LCOV - code coverage report
Current view: top level - src/backend/optimizer/plan - planner.c (source / functions) Hit Total Coverage
Test: PostgreSQL 17devel Lines: 2129 2199 96.8 %
Date: 2024-03-29 14:11:41 Functions: 58 58 100.0 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : /*-------------------------------------------------------------------------
       2             :  *
       3             :  * planner.c
       4             :  *    The query optimizer external interface.
       5             :  *
       6             :  * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
       7             :  * Portions Copyright (c) 1994, Regents of the University of California
       8             :  *
       9             :  *
      10             :  * IDENTIFICATION
      11             :  *    src/backend/optimizer/plan/planner.c
      12             :  *
      13             :  *-------------------------------------------------------------------------
      14             :  */
      15             : 
      16             : #include "postgres.h"
      17             : 
      18             : #include <limits.h>
      19             : #include <math.h>
      20             : 
      21             : #include "access/genam.h"
      22             : #include "access/parallel.h"
      23             : #include "access/sysattr.h"
      24             : #include "access/table.h"
      25             : #include "catalog/pg_aggregate.h"
      26             : #include "catalog/pg_constraint.h"
      27             : #include "catalog/pg_inherits.h"
      28             : #include "catalog/pg_proc.h"
      29             : #include "catalog/pg_type.h"
      30             : #include "executor/executor.h"
      31             : #include "foreign/fdwapi.h"
      32             : #include "jit/jit.h"
      33             : #include "lib/bipartite_match.h"
      34             : #include "lib/knapsack.h"
      35             : #include "miscadmin.h"
      36             : #include "nodes/makefuncs.h"
      37             : #include "nodes/nodeFuncs.h"
      38             : #ifdef OPTIMIZER_DEBUG
      39             : #include "nodes/print.h"
      40             : #endif
      41             : #include "nodes/supportnodes.h"
      42             : #include "optimizer/appendinfo.h"
      43             : #include "optimizer/clauses.h"
      44             : #include "optimizer/cost.h"
      45             : #include "optimizer/optimizer.h"
      46             : #include "optimizer/paramassign.h"
      47             : #include "optimizer/pathnode.h"
      48             : #include "optimizer/paths.h"
      49             : #include "optimizer/plancat.h"
      50             : #include "optimizer/planmain.h"
      51             : #include "optimizer/planner.h"
      52             : #include "optimizer/prep.h"
      53             : #include "optimizer/subselect.h"
      54             : #include "optimizer/tlist.h"
      55             : #include "parser/analyze.h"
      56             : #include "parser/parse_agg.h"
      57             : #include "parser/parse_clause.h"
      58             : #include "parser/parse_relation.h"
      59             : #include "parser/parsetree.h"
      60             : #include "partitioning/partdesc.h"
      61             : #include "utils/lsyscache.h"
      62             : #include "utils/rel.h"
      63             : #include "utils/selfuncs.h"
      64             : 
      65             : /* GUC parameters */
      66             : double      cursor_tuple_fraction = DEFAULT_CURSOR_TUPLE_FRACTION;
      67             : int         debug_parallel_query = DEBUG_PARALLEL_OFF;
      68             : bool        parallel_leader_participation = true;
      69             : 
      70             : /* Hook for plugins to get control in planner() */
      71             : planner_hook_type planner_hook = NULL;
      72             : 
      73             : /* Hook for plugins to get control when grouping_planner() plans upper rels */
      74             : create_upper_paths_hook_type create_upper_paths_hook = NULL;
      75             : 
      76             : 
      77             : /* Expression kind codes for preprocess_expression */
      78             : #define EXPRKIND_QUAL               0
      79             : #define EXPRKIND_TARGET             1
      80             : #define EXPRKIND_RTFUNC             2
      81             : #define EXPRKIND_RTFUNC_LATERAL     3
      82             : #define EXPRKIND_VALUES             4
      83             : #define EXPRKIND_VALUES_LATERAL     5
      84             : #define EXPRKIND_LIMIT              6
      85             : #define EXPRKIND_APPINFO            7
      86             : #define EXPRKIND_PHV                8
      87             : #define EXPRKIND_TABLESAMPLE        9
      88             : #define EXPRKIND_ARBITER_ELEM       10
      89             : #define EXPRKIND_TABLEFUNC          11
      90             : #define EXPRKIND_TABLEFUNC_LATERAL  12
      91             : 
      92             : /*
      93             :  * Data specific to grouping sets
      94             :  */
      95             : typedef struct
      96             : {
      97             :     List       *rollups;
      98             :     List       *hash_sets_idx;
      99             :     double      dNumHashGroups;
     100             :     bool        any_hashable;
     101             :     Bitmapset  *unsortable_refs;
     102             :     Bitmapset  *unhashable_refs;
     103             :     List       *unsortable_sets;
     104             :     int        *tleref_to_colnum_map;
     105             : } grouping_sets_data;
     106             : 
     107             : /*
     108             :  * Temporary structure for use during WindowClause reordering in order to be
     109             :  * able to sort WindowClauses on partitioning/ordering prefix.
     110             :  */
     111             : typedef struct
     112             : {
     113             :     WindowClause *wc;
     114             :     List       *uniqueOrder;    /* A List of unique ordering/partitioning
     115             :                                  * clauses per Window */
     116             : } WindowClauseSortData;
     117             : 
     118             : /* Passthrough data for standard_qp_callback */
     119             : typedef struct
     120             : {
     121             :     List       *activeWindows;  /* active windows, if any */
     122             :     grouping_sets_data *gset_data;  /* grouping sets data, if any */
     123             :     SetOperationStmt *setop;    /* parent set operation or NULL if not a
     124             :                                  * subquery belonging to a set operation */
     125             : } standard_qp_extra;
     126             : 
     127             : /* Local functions */
     128             : static Node *preprocess_expression(PlannerInfo *root, Node *expr, int kind);
     129             : static void preprocess_qual_conditions(PlannerInfo *root, Node *jtnode);
     130             : static void grouping_planner(PlannerInfo *root, double tuple_fraction);
     131             : static grouping_sets_data *preprocess_grouping_sets(PlannerInfo *root);
     132             : static List *remap_to_groupclause_idx(List *groupClause, List *gsets,
     133             :                                       int *tleref_to_colnum_map);
     134             : static void preprocess_rowmarks(PlannerInfo *root);
     135             : static double preprocess_limit(PlannerInfo *root,
     136             :                                double tuple_fraction,
     137             :                                int64 *offset_est, int64 *count_est);
     138             : static void remove_useless_groupby_columns(PlannerInfo *root);
     139             : static List *groupclause_apply_groupingset(PlannerInfo *root, List *force);
     140             : static List *extract_rollup_sets(List *groupingSets);
     141             : static List *reorder_grouping_sets(List *groupingSets, List *sortclause);
     142             : static void standard_qp_callback(PlannerInfo *root, void *extra);
     143             : static double get_number_of_groups(PlannerInfo *root,
     144             :                                    double path_rows,
     145             :                                    grouping_sets_data *gd,
     146             :                                    List *target_list);
     147             : static RelOptInfo *create_grouping_paths(PlannerInfo *root,
     148             :                                          RelOptInfo *input_rel,
     149             :                                          PathTarget *target,
     150             :                                          bool target_parallel_safe,
     151             :                                          grouping_sets_data *gd);
     152             : static bool is_degenerate_grouping(PlannerInfo *root);
     153             : static void create_degenerate_grouping_paths(PlannerInfo *root,
     154             :                                              RelOptInfo *input_rel,
     155             :                                              RelOptInfo *grouped_rel);
     156             : static RelOptInfo *make_grouping_rel(PlannerInfo *root, RelOptInfo *input_rel,
     157             :                                      PathTarget *target, bool target_parallel_safe,
     158             :                                      Node *havingQual);
     159             : static void create_ordinary_grouping_paths(PlannerInfo *root,
     160             :                                            RelOptInfo *input_rel,
     161             :                                            RelOptInfo *grouped_rel,
     162             :                                            const AggClauseCosts *agg_costs,
     163             :                                            grouping_sets_data *gd,
     164             :                                            GroupPathExtraData *extra,
     165             :                                            RelOptInfo **partially_grouped_rel_p);
     166             : static void consider_groupingsets_paths(PlannerInfo *root,
     167             :                                         RelOptInfo *grouped_rel,
     168             :                                         Path *path,
     169             :                                         bool is_sorted,
     170             :                                         bool can_hash,
     171             :                                         grouping_sets_data *gd,
     172             :                                         const AggClauseCosts *agg_costs,
     173             :                                         double dNumGroups);
     174             : static RelOptInfo *create_window_paths(PlannerInfo *root,
     175             :                                        RelOptInfo *input_rel,
     176             :                                        PathTarget *input_target,
     177             :                                        PathTarget *output_target,
     178             :                                        bool output_target_parallel_safe,
     179             :                                        WindowFuncLists *wflists,
     180             :                                        List *activeWindows);
     181             : static void create_one_window_path(PlannerInfo *root,
     182             :                                    RelOptInfo *window_rel,
     183             :                                    Path *path,
     184             :                                    PathTarget *input_target,
     185             :                                    PathTarget *output_target,
     186             :                                    WindowFuncLists *wflists,
     187             :                                    List *activeWindows);
     188             : static RelOptInfo *create_distinct_paths(PlannerInfo *root,
     189             :                                          RelOptInfo *input_rel,
     190             :                                          PathTarget *target);
     191             : static void create_partial_distinct_paths(PlannerInfo *root,
     192             :                                           RelOptInfo *input_rel,
     193             :                                           RelOptInfo *final_distinct_rel,
     194             :                                           PathTarget *target);
     195             : static RelOptInfo *create_final_distinct_paths(PlannerInfo *root,
     196             :                                                RelOptInfo *input_rel,
     197             :                                                RelOptInfo *distinct_rel);
     198             : static RelOptInfo *create_ordered_paths(PlannerInfo *root,
     199             :                                         RelOptInfo *input_rel,
     200             :                                         PathTarget *target,
     201             :                                         bool target_parallel_safe,
     202             :                                         double limit_tuples);
     203             : static PathTarget *make_group_input_target(PlannerInfo *root,
     204             :                                            PathTarget *final_target);
     205             : static PathTarget *make_partial_grouping_target(PlannerInfo *root,
     206             :                                                 PathTarget *grouping_target,
     207             :                                                 Node *havingQual);
     208             : static List *postprocess_setop_tlist(List *new_tlist, List *orig_tlist);
     209             : static void optimize_window_clauses(PlannerInfo *root,
     210             :                                     WindowFuncLists *wflists);
     211             : static List *select_active_windows(PlannerInfo *root, WindowFuncLists *wflists);
     212             : static PathTarget *make_window_input_target(PlannerInfo *root,
     213             :                                             PathTarget *final_target,
     214             :                                             List *activeWindows);
     215             : static List *make_pathkeys_for_window(PlannerInfo *root, WindowClause *wc,
     216             :                                       List *tlist);
     217             : static PathTarget *make_sort_input_target(PlannerInfo *root,
     218             :                                           PathTarget *final_target,
     219             :                                           bool *have_postponed_srfs);
     220             : static void adjust_paths_for_srfs(PlannerInfo *root, RelOptInfo *rel,
     221             :                                   List *targets, List *targets_contain_srfs);
     222             : static void add_paths_to_grouping_rel(PlannerInfo *root, RelOptInfo *input_rel,
     223             :                                       RelOptInfo *grouped_rel,
     224             :                                       RelOptInfo *partially_grouped_rel,
     225             :                                       const AggClauseCosts *agg_costs,
     226             :                                       grouping_sets_data *gd,
     227             :                                       double dNumGroups,
     228             :                                       GroupPathExtraData *extra);
     229             : static RelOptInfo *create_partial_grouping_paths(PlannerInfo *root,
     230             :                                                  RelOptInfo *grouped_rel,
     231             :                                                  RelOptInfo *input_rel,
     232             :                                                  grouping_sets_data *gd,
     233             :                                                  GroupPathExtraData *extra,
     234             :                                                  bool force_rel_creation);
     235             : static void gather_grouping_paths(PlannerInfo *root, RelOptInfo *rel);
     236             : static bool can_partial_agg(PlannerInfo *root);
     237             : static void apply_scanjoin_target_to_paths(PlannerInfo *root,
     238             :                                            RelOptInfo *rel,
     239             :                                            List *scanjoin_targets,
     240             :                                            List *scanjoin_targets_contain_srfs,
     241             :                                            bool scanjoin_target_parallel_safe,
     242             :                                            bool tlist_same_exprs);
     243             : static void create_partitionwise_grouping_paths(PlannerInfo *root,
     244             :                                                 RelOptInfo *input_rel,
     245             :                                                 RelOptInfo *grouped_rel,
     246             :                                                 RelOptInfo *partially_grouped_rel,
     247             :                                                 const AggClauseCosts *agg_costs,
     248             :                                                 grouping_sets_data *gd,
     249             :                                                 PartitionwiseAggregateType patype,
     250             :                                                 GroupPathExtraData *extra);
     251             : static bool group_by_has_partkey(RelOptInfo *input_rel,
     252             :                                  List *targetList,
     253             :                                  List *groupClause);
     254             : static int  common_prefix_cmp(const void *a, const void *b);
     255             : static List *generate_setop_child_grouplist(SetOperationStmt *op,
     256             :                                             List *targetlist);
     257             : 
     258             : 
     259             : /*****************************************************************************
     260             :  *
     261             :  *     Query optimizer entry point
     262             :  *
     263             :  * To support loadable plugins that monitor or modify planner behavior,
     264             :  * we provide a hook variable that lets a plugin get control before and
     265             :  * after the standard planning process.  The plugin would normally call
     266             :  * standard_planner().
     267             :  *
     268             :  * Note to plugin authors: standard_planner() scribbles on its Query input,
     269             :  * so you'd better copy that data structure if you want to plan more than once.
     270             :  *
     271             :  *****************************************************************************/
     272             : PlannedStmt *
     273      429080 : planner(Query *parse, const char *query_string, int cursorOptions,
     274             :         ParamListInfo boundParams)
     275             : {
     276             :     PlannedStmt *result;
     277             : 
     278      429080 :     if (planner_hook)
     279       80052 :         result = (*planner_hook) (parse, query_string, cursorOptions, boundParams);
     280             :     else
     281      349028 :         result = standard_planner(parse, query_string, cursorOptions, boundParams);
     282      425284 :     return result;
     283             : }
     284             : 
     285             : PlannedStmt *
     286      429080 : standard_planner(Query *parse, const char *query_string, int cursorOptions,
     287             :                  ParamListInfo boundParams)
     288             : {
     289             :     PlannedStmt *result;
     290             :     PlannerGlobal *glob;
     291             :     double      tuple_fraction;
     292             :     PlannerInfo *root;
     293             :     RelOptInfo *final_rel;
     294             :     Path       *best_path;
     295             :     Plan       *top_plan;
     296             :     ListCell   *lp,
     297             :                *lr;
     298             : 
     299             :     /*
     300             :      * Set up global state for this planner invocation.  This data is needed
     301             :      * across all levels of sub-Query that might exist in the given command,
     302             :      * so we keep it in a separate struct that's linked to by each per-Query
     303             :      * PlannerInfo.
     304             :      */
     305      429080 :     glob = makeNode(PlannerGlobal);
     306             : 
     307      429080 :     glob->boundParams = boundParams;
     308      429080 :     glob->subplans = NIL;
     309      429080 :     glob->subpaths = NIL;
     310      429080 :     glob->subroots = NIL;
     311      429080 :     glob->rewindPlanIDs = NULL;
     312      429080 :     glob->finalrtable = NIL;
     313      429080 :     glob->finalrteperminfos = NIL;
     314      429080 :     glob->finalrowmarks = NIL;
     315      429080 :     glob->resultRelations = NIL;
     316      429080 :     glob->appendRelations = NIL;
     317      429080 :     glob->relationOids = NIL;
     318      429080 :     glob->invalItems = NIL;
     319      429080 :     glob->paramExecTypes = NIL;
     320      429080 :     glob->lastPHId = 0;
     321      429080 :     glob->lastRowMarkId = 0;
     322      429080 :     glob->lastPlanNodeId = 0;
     323      429080 :     glob->transientPlan = false;
     324      429080 :     glob->dependsOnRole = false;
     325             : 
     326             :     /*
     327             :      * Assess whether it's feasible to use parallel mode for this query. We
     328             :      * can't do this in a standalone backend, or if the command will try to
     329             :      * modify any data, or if this is a cursor operation, or if GUCs are set
     330             :      * to values that don't permit parallelism, or if parallel-unsafe
     331             :      * functions are present in the query tree.
     332             :      *
     333             :      * (Note that we do allow CREATE TABLE AS, SELECT INTO, and CREATE
     334             :      * MATERIALIZED VIEW to use parallel plans, but this is safe only because
     335             :      * the command is writing into a completely new table which workers won't
     336             :      * be able to see.  If the workers could see the table, the fact that
     337             :      * group locking would cause them to ignore the leader's heavyweight GIN
     338             :      * page locks would make this unsafe.  We'll have to fix that somehow if
     339             :      * we want to allow parallel inserts in general; updates and deletes have
     340             :      * additional problems especially around combo CIDs.)
     341             :      *
     342             :      * For now, we don't try to use parallel mode if we're running inside a
     343             :      * parallel worker.  We might eventually be able to relax this
     344             :      * restriction, but for now it seems best not to have parallel workers
     345             :      * trying to create their own parallel workers.
     346             :      */
     347      429080 :     if ((cursorOptions & CURSOR_OPT_PARALLEL_OK) != 0 &&
     348      404544 :         IsUnderPostmaster &&
     349      404544 :         parse->commandType == CMD_SELECT &&
     350      321580 :         !parse->hasModifyingCTE &&
     351      321440 :         max_parallel_workers_per_gather > 0 &&
     352      320976 :         !IsParallelWorker())
     353             :     {
     354             :         /* all the cheap tests pass, so scan the query tree */
     355      320924 :         glob->maxParallelHazard = max_parallel_hazard(parse);
     356      320924 :         glob->parallelModeOK = (glob->maxParallelHazard != PROPARALLEL_UNSAFE);
     357             :     }
     358             :     else
     359             :     {
     360             :         /* skip the query tree scan, just assume it's unsafe */
     361      108156 :         glob->maxParallelHazard = PROPARALLEL_UNSAFE;
     362      108156 :         glob->parallelModeOK = false;
     363             :     }
     364             : 
     365             :     /*
     366             :      * glob->parallelModeNeeded is normally set to false here and changed to
     367             :      * true during plan creation if a Gather or Gather Merge plan is actually
     368             :      * created (cf. create_gather_plan, create_gather_merge_plan).
     369             :      *
     370             :      * However, if debug_parallel_query = on or debug_parallel_query =
     371             :      * regress, then we impose parallel mode whenever it's safe to do so, even
     372             :      * if the final plan doesn't use parallelism.  It's not safe to do so if
     373             :      * the query contains anything parallel-unsafe; parallelModeOK will be
     374             :      * false in that case.  Note that parallelModeOK can't change after this
     375             :      * point. Otherwise, everything in the query is either parallel-safe or
     376             :      * parallel-restricted, and in either case it should be OK to impose
     377             :      * parallel-mode restrictions.  If that ends up breaking something, then
     378             :      * either some function the user included in the query is incorrectly
     379             :      * labeled as parallel-safe or parallel-restricted when in reality it's
     380             :      * parallel-unsafe, or else the query planner itself has a bug.
     381             :      */
     382      695370 :     glob->parallelModeNeeded = glob->parallelModeOK &&
     383      266290 :         (debug_parallel_query != DEBUG_PARALLEL_OFF);
     384             : 
     385             :     /* Determine what fraction of the plan is likely to be scanned */
     386      429080 :     if (cursorOptions & CURSOR_OPT_FAST_PLAN)
     387             :     {
     388             :         /*
     389             :          * We have no real idea how many tuples the user will ultimately FETCH
     390             :          * from a cursor, but it is often the case that he doesn't want 'em
     391             :          * all, or would prefer a fast-start plan anyway so that he can
     392             :          * process some of the tuples sooner.  Use a GUC parameter to decide
     393             :          * what fraction to optimize for.
     394             :          */
     395        2962 :         tuple_fraction = cursor_tuple_fraction;
     396             : 
     397             :         /*
     398             :          * We document cursor_tuple_fraction as simply being a fraction, which
     399             :          * means the edge cases 0 and 1 have to be treated specially here.  We
     400             :          * convert 1 to 0 ("all the tuples") and 0 to a very small fraction.
     401             :          */
     402        2962 :         if (tuple_fraction >= 1.0)
     403           0 :             tuple_fraction = 0.0;
     404        2962 :         else if (tuple_fraction <= 0.0)
     405           0 :             tuple_fraction = 1e-10;
     406             :     }
     407             :     else
     408             :     {
     409             :         /* Default assumption is we need all the tuples */
     410      426118 :         tuple_fraction = 0.0;
     411             :     }
     412             : 
     413             :     /* primary planning entry point (may recurse for subqueries) */
     414      429080 :     root = subquery_planner(glob, parse, NULL,
     415             :                             false, tuple_fraction);
     416             : 
     417             :     /* Select best Path and turn it into a Plan */
     418      425462 :     final_rel = fetch_upper_rel(root, UPPERREL_FINAL, NULL);
     419      425462 :     best_path = get_cheapest_fractional_path(final_rel, tuple_fraction);
     420             : 
     421      425462 :     top_plan = create_plan(root, best_path);
     422             : 
     423             :     /*
     424             :      * If creating a plan for a scrollable cursor, make sure it can run
     425             :      * backwards on demand.  Add a Material node at the top at need.
     426             :      */
     427      425284 :     if (cursorOptions & CURSOR_OPT_SCROLL)
     428             :     {
     429         264 :         if (!ExecSupportsBackwardScan(top_plan))
     430          30 :             top_plan = materialize_finished_plan(top_plan);
     431             :     }
     432             : 
     433             :     /*
     434             :      * Optionally add a Gather node for testing purposes, provided this is
     435             :      * actually a safe thing to do.
     436             :      *
     437             :      * We can add Gather even when top_plan has parallel-safe initPlans, but
     438             :      * then we have to move the initPlans to the Gather node because of
     439             :      * SS_finalize_plan's limitations.  That would cause cosmetic breakage of
     440             :      * regression tests when debug_parallel_query = regress, because initPlans
     441             :      * that would normally appear on the top_plan move to the Gather, causing
     442             :      * them to disappear from EXPLAIN output.  That doesn't seem worth kluging
     443             :      * EXPLAIN to hide, so skip it when debug_parallel_query = regress.
     444             :      */
     445      425284 :     if (debug_parallel_query != DEBUG_PARALLEL_OFF &&
     446         116 :         top_plan->parallel_safe &&
     447          36 :         (top_plan->initPlan == NIL ||
     448           0 :          debug_parallel_query != DEBUG_PARALLEL_REGRESS))
     449             :     {
     450          36 :         Gather     *gather = makeNode(Gather);
     451             :         Cost        initplan_cost;
     452             :         bool        unsafe_initplans;
     453             : 
     454          36 :         gather->plan.targetlist = top_plan->targetlist;
     455          36 :         gather->plan.qual = NIL;
     456          36 :         gather->plan.lefttree = top_plan;
     457          36 :         gather->plan.righttree = NULL;
     458          36 :         gather->num_workers = 1;
     459          36 :         gather->single_copy = true;
     460          36 :         gather->invisible = (debug_parallel_query == DEBUG_PARALLEL_REGRESS);
     461             : 
     462             :         /* Transfer any initPlans to the new top node */
     463          36 :         gather->plan.initPlan = top_plan->initPlan;
     464          36 :         top_plan->initPlan = NIL;
     465             : 
     466             :         /*
     467             :          * Since this Gather has no parallel-aware descendants to signal to,
     468             :          * we don't need a rescan Param.
     469             :          */
     470          36 :         gather->rescan_param = -1;
     471             : 
     472             :         /*
     473             :          * Ideally we'd use cost_gather here, but setting up dummy path data
     474             :          * to satisfy it doesn't seem much cleaner than knowing what it does.
     475             :          */
     476          36 :         gather->plan.startup_cost = top_plan->startup_cost +
     477             :             parallel_setup_cost;
     478          36 :         gather->plan.total_cost = top_plan->total_cost +
     479          36 :             parallel_setup_cost + parallel_tuple_cost * top_plan->plan_rows;
     480          36 :         gather->plan.plan_rows = top_plan->plan_rows;
     481          36 :         gather->plan.plan_width = top_plan->plan_width;
     482          36 :         gather->plan.parallel_aware = false;
     483          36 :         gather->plan.parallel_safe = false;
     484             : 
     485             :         /*
     486             :          * Delete the initplans' cost from top_plan.  We needn't add it to the
     487             :          * Gather node, since the above coding already included it there.
     488             :          */
     489          36 :         SS_compute_initplan_cost(gather->plan.initPlan,
     490             :                                  &initplan_cost, &unsafe_initplans);
     491          36 :         top_plan->startup_cost -= initplan_cost;
     492          36 :         top_plan->total_cost -= initplan_cost;
     493             : 
     494             :         /* use parallel mode for parallel plans. */
     495          36 :         root->glob->parallelModeNeeded = true;
     496             : 
     497          36 :         top_plan = &gather->plan;
     498             :     }
     499             : 
     500             :     /*
     501             :      * If any Params were generated, run through the plan tree and compute
     502             :      * each plan node's extParam/allParam sets.  Ideally we'd merge this into
     503             :      * set_plan_references' tree traversal, but for now it has to be separate
     504             :      * because we need to visit subplans before not after main plan.
     505             :      */
     506      425284 :     if (glob->paramExecTypes != NIL)
     507             :     {
     508             :         Assert(list_length(glob->subplans) == list_length(glob->subroots));
     509      179932 :         forboth(lp, glob->subplans, lr, glob->subroots)
     510             :         {
     511       35750 :             Plan       *subplan = (Plan *) lfirst(lp);
     512       35750 :             PlannerInfo *subroot = lfirst_node(PlannerInfo, lr);
     513             : 
     514       35750 :             SS_finalize_plan(subroot, subplan);
     515             :         }
     516      144182 :         SS_finalize_plan(root, top_plan);
     517             :     }
     518             : 
     519             :     /* final cleanup of the plan */
     520             :     Assert(glob->finalrtable == NIL);
     521             :     Assert(glob->finalrteperminfos == NIL);
     522             :     Assert(glob->finalrowmarks == NIL);
     523             :     Assert(glob->resultRelations == NIL);
     524             :     Assert(glob->appendRelations == NIL);
     525      425284 :     top_plan = set_plan_references(root, top_plan);
     526             :     /* ... and the subplans (both regular subplans and initplans) */
     527             :     Assert(list_length(glob->subplans) == list_length(glob->subroots));
     528      461034 :     forboth(lp, glob->subplans, lr, glob->subroots)
     529             :     {
     530       35750 :         Plan       *subplan = (Plan *) lfirst(lp);
     531       35750 :         PlannerInfo *subroot = lfirst_node(PlannerInfo, lr);
     532             : 
     533       35750 :         lfirst(lp) = set_plan_references(subroot, subplan);
     534             :     }
     535             : 
     536             :     /* build the PlannedStmt result */
     537      425284 :     result = makeNode(PlannedStmt);
     538             : 
     539      425284 :     result->commandType = parse->commandType;
     540      425284 :     result->queryId = parse->queryId;
     541      425284 :     result->hasReturning = (parse->returningList != NIL);
     542      425284 :     result->hasModifyingCTE = parse->hasModifyingCTE;
     543      425284 :     result->canSetTag = parse->canSetTag;
     544      425284 :     result->transientPlan = glob->transientPlan;
     545      425284 :     result->dependsOnRole = glob->dependsOnRole;
     546      425284 :     result->parallelModeNeeded = glob->parallelModeNeeded;
     547      425284 :     result->planTree = top_plan;
     548      425284 :     result->rtable = glob->finalrtable;
     549      425284 :     result->permInfos = glob->finalrteperminfos;
     550      425284 :     result->resultRelations = glob->resultRelations;
     551      425284 :     result->appendRelations = glob->appendRelations;
     552      425284 :     result->subplans = glob->subplans;
     553      425284 :     result->rewindPlanIDs = glob->rewindPlanIDs;
     554      425284 :     result->rowMarks = glob->finalrowmarks;
     555      425284 :     result->relationOids = glob->relationOids;
     556      425284 :     result->invalItems = glob->invalItems;
     557      425284 :     result->paramExecTypes = glob->paramExecTypes;
     558             :     /* utilityStmt should be null, but we might as well copy it */
     559      425284 :     result->utilityStmt = parse->utilityStmt;
     560      425284 :     result->stmt_location = parse->stmt_location;
     561      425284 :     result->stmt_len = parse->stmt_len;
     562             : 
     563      425284 :     result->jitFlags = PGJIT_NONE;
     564      425284 :     if (jit_enabled && jit_above_cost >= 0 &&
     565      424936 :         top_plan->total_cost > jit_above_cost)
     566             :     {
     567        1350 :         result->jitFlags |= PGJIT_PERFORM;
     568             : 
     569             :         /*
     570             :          * Decide how much effort should be put into generating better code.
     571             :          */
     572        1350 :         if (jit_optimize_above_cost >= 0 &&
     573        1350 :             top_plan->total_cost > jit_optimize_above_cost)
     574         970 :             result->jitFlags |= PGJIT_OPT3;
     575        1350 :         if (jit_inline_above_cost >= 0 &&
     576        1350 :             top_plan->total_cost > jit_inline_above_cost)
     577         970 :             result->jitFlags |= PGJIT_INLINE;
     578             : 
     579             :         /*
     580             :          * Decide which operations should be JITed.
     581             :          */
     582        1350 :         if (jit_expressions)
     583        1350 :             result->jitFlags |= PGJIT_EXPR;
     584        1350 :         if (jit_tuple_deforming)
     585        1350 :             result->jitFlags |= PGJIT_DEFORM;
     586             :     }
     587             : 
     588      425284 :     if (glob->partition_directory != NULL)
     589       10888 :         DestroyPartitionDirectory(glob->partition_directory);
     590             : 
     591      425284 :     return result;
     592             : }
     593             : 
     594             : 
     595             : /*--------------------
     596             :  * subquery_planner
     597             :  *    Invokes the planner on a subquery.  We recurse to here for each
     598             :  *    sub-SELECT found in the query tree.
     599             :  *
     600             :  * glob is the global state for the current planner run.
     601             :  * parse is the querytree produced by the parser & rewriter.
     602             :  * parent_root is the immediate parent Query's info (NULL at the top level).
     603             :  * hasRecursion is true if this is a recursive WITH query.
     604             :  * tuple_fraction is the fraction of tuples we expect will be retrieved.
     605             :  * tuple_fraction is interpreted as explained for grouping_planner, below.
     606             :  *
     607             :  * Basically, this routine does the stuff that should only be done once
     608             :  * per Query object.  It then calls grouping_planner.  At one time,
     609             :  * grouping_planner could be invoked recursively on the same Query object;
     610             :  * that's not currently true, but we keep the separation between the two
     611             :  * routines anyway, in case we need it again someday.
     612             :  *
     613             :  * subquery_planner will be called recursively to handle sub-Query nodes
     614             :  * found within the query's expressions and rangetable.
     615             :  *
     616             :  * Returns the PlannerInfo struct ("root") that contains all data generated
     617             :  * while planning the subquery.  In particular, the Path(s) attached to
     618             :  * the (UPPERREL_FINAL, NULL) upperrel represent our conclusions about the
     619             :  * cheapest way(s) to implement the query.  The top level will select the
     620             :  * best Path and pass it through createplan.c to produce a finished Plan.
     621             :  *--------------------
     622             :  */
     623             : PlannerInfo *
     624      485716 : subquery_planner(PlannerGlobal *glob, Query *parse,
     625             :                  PlannerInfo *parent_root,
     626             :                  bool hasRecursion, double tuple_fraction)
     627             : {
     628             :     PlannerInfo *root;
     629             :     List       *newWithCheckOptions;
     630             :     List       *newHaving;
     631             :     bool        hasOuterJoins;
     632             :     bool        hasResultRTEs;
     633             :     RelOptInfo *final_rel;
     634             :     ListCell   *l;
     635             : 
     636             :     /* Create a PlannerInfo data structure for this subquery */
     637      485716 :     root = makeNode(PlannerInfo);
     638      485716 :     root->parse = parse;
     639      485716 :     root->glob = glob;
     640      485716 :     root->query_level = parent_root ? parent_root->query_level + 1 : 1;
     641      485716 :     root->parent_root = parent_root;
     642      485716 :     root->plan_params = NIL;
     643      485716 :     root->outer_params = NULL;
     644      485716 :     root->planner_cxt = CurrentMemoryContext;
     645      485716 :     root->init_plans = NIL;
     646      485716 :     root->cte_plan_ids = NIL;
     647      485716 :     root->multiexpr_params = NIL;
     648      485716 :     root->join_domains = NIL;
     649      485716 :     root->eq_classes = NIL;
     650      485716 :     root->ec_merging_done = false;
     651      485716 :     root->last_rinfo_serial = 0;
     652      485716 :     root->all_result_relids =
     653      485716 :         parse->resultRelation ? bms_make_singleton(parse->resultRelation) : NULL;
     654      485716 :     root->leaf_result_relids = NULL; /* we'll find out leaf-ness later */
     655      485716 :     root->append_rel_list = NIL;
     656      485716 :     root->row_identity_vars = NIL;
     657      485716 :     root->rowMarks = NIL;
     658      485716 :     memset(root->upper_rels, 0, sizeof(root->upper_rels));
     659      485716 :     memset(root->upper_targets, 0, sizeof(root->upper_targets));
     660      485716 :     root->processed_groupClause = NIL;
     661      485716 :     root->processed_distinctClause = NIL;
     662      485716 :     root->processed_tlist = NIL;
     663      485716 :     root->update_colnos = NIL;
     664      485716 :     root->grouping_map = NULL;
     665      485716 :     root->minmax_aggs = NIL;
     666      485716 :     root->qual_security_level = 0;
     667      485716 :     root->hasPseudoConstantQuals = false;
     668      485716 :     root->hasAlternativeSubPlans = false;
     669      485716 :     root->placeholdersFrozen = false;
     670      485716 :     root->hasRecursion = hasRecursion;
     671      485716 :     if (hasRecursion)
     672         808 :         root->wt_param_id = assign_special_exec_param(root);
     673             :     else
     674      484908 :         root->wt_param_id = -1;
     675      485716 :     root->non_recursive_path = NULL;
     676      485716 :     root->partColsUpdated = false;
     677             : 
     678             :     /*
     679             :      * Create the top-level join domain.  This won't have valid contents until
     680             :      * deconstruct_jointree fills it in, but the node needs to exist before
     681             :      * that so we can build EquivalenceClasses referencing it.
     682             :      */
     683      485716 :     root->join_domains = list_make1(makeNode(JoinDomain));
     684             : 
     685             :     /*
     686             :      * If there is a WITH list, process each WITH query and either convert it
     687             :      * to RTE_SUBQUERY RTE(s) or build an initplan SubPlan structure for it.
     688             :      */
     689      485716 :     if (parse->cteList)
     690        2392 :         SS_process_ctes(root);
     691             : 
     692             :     /*
     693             :      * If it's a MERGE command, transform the joinlist as appropriate.
     694             :      */
     695      485710 :     transform_MERGE_to_join(parse);
     696             : 
     697             :     /*
     698             :      * If the FROM clause is empty, replace it with a dummy RTE_RESULT RTE, so
     699             :      * that we don't need so many special cases to deal with that situation.
     700             :      */
     701      485710 :     replace_empty_jointree(parse);
     702             : 
     703             :     /*
     704             :      * Look for ANY and EXISTS SubLinks in WHERE and JOIN/ON clauses, and try
     705             :      * to transform them into joins.  Note that this step does not descend
     706             :      * into subqueries; if we pull up any subqueries below, their SubLinks are
     707             :      * processed just before pulling them up.
     708             :      */
     709      485710 :     if (parse->hasSubLinks)
     710       27784 :         pull_up_sublinks(root);
     711             : 
     712             :     /*
     713             :      * Scan the rangetable for function RTEs, do const-simplification on them,
     714             :      * and then inline them if possible (producing subqueries that might get
     715             :      * pulled up next).  Recursion issues here are handled in the same way as
     716             :      * for SubLinks.
     717             :      */
     718      485710 :     preprocess_function_rtes(root);
     719             : 
     720             :     /*
     721             :      * Check to see if any subqueries in the jointree can be merged into this
     722             :      * query.
     723             :      */
     724      485704 :     pull_up_subqueries(root);
     725             : 
     726             :     /*
     727             :      * If this is a simple UNION ALL query, flatten it into an appendrel. We
     728             :      * do this now because it requires applying pull_up_subqueries to the leaf
     729             :      * queries of the UNION ALL, which weren't touched above because they
     730             :      * weren't referenced by the jointree (they will be after we do this).
     731             :      */
     732      485698 :     if (parse->setOperations)
     733        5482 :         flatten_simple_union_all(root);
     734             : 
     735             :     /*
     736             :      * Survey the rangetable to see what kinds of entries are present.  We can
     737             :      * skip some later processing if relevant SQL features are not used; for
     738             :      * example if there are no JOIN RTEs we can avoid the expense of doing
     739             :      * flatten_join_alias_vars().  This must be done after we have finished
     740             :      * adding rangetable entries, of course.  (Note: actually, processing of
     741             :      * inherited or partitioned rels can cause RTEs for their child tables to
     742             :      * get added later; but those must all be RTE_RELATION entries, so they
     743             :      * don't invalidate the conclusions drawn here.)
     744             :      */
     745      485698 :     root->hasJoinRTEs = false;
     746      485698 :     root->hasLateralRTEs = false;
     747      485698 :     hasOuterJoins = false;
     748      485698 :     hasResultRTEs = false;
     749     1289098 :     foreach(l, parse->rtable)
     750             :     {
     751      803400 :         RangeTblEntry *rte = lfirst_node(RangeTblEntry, l);
     752             : 
     753      803400 :         switch (rte->rtekind)
     754             :         {
     755      414982 :             case RTE_RELATION:
     756      414982 :                 if (rte->inh)
     757             :                 {
     758             :                     /*
     759             :                      * Check to see if the relation actually has any children;
     760             :                      * if not, clear the inh flag so we can treat it as a
     761             :                      * plain base relation.
     762             :                      *
     763             :                      * Note: this could give a false-positive result, if the
     764             :                      * rel once had children but no longer does.  We used to
     765             :                      * be able to clear rte->inh later on when we discovered
     766             :                      * that, but no more; we have to handle such cases as
     767             :                      * full-fledged inheritance.
     768             :                      */
     769      332394 :                     rte->inh = has_subclass(rte->relid);
     770             :                 }
     771      414982 :                 break;
     772       75070 :             case RTE_JOIN:
     773       75070 :                 root->hasJoinRTEs = true;
     774       75070 :                 if (IS_OUTER_JOIN(rte->jointype))
     775       44254 :                     hasOuterJoins = true;
     776       75070 :                 break;
     777      209434 :             case RTE_RESULT:
     778      209434 :                 hasResultRTEs = true;
     779      209434 :                 break;
     780      103914 :             default:
     781             :                 /* No work here for other RTE types */
     782      103914 :                 break;
     783             :         }
     784             : 
     785      803400 :         if (rte->lateral)
     786        9812 :             root->hasLateralRTEs = true;
     787             : 
     788             :         /*
     789             :          * We can also determine the maximum security level required for any
     790             :          * securityQuals now.  Addition of inheritance-child RTEs won't affect
     791             :          * this, because child tables don't have their own securityQuals; see
     792             :          * expand_single_inheritance_child().
     793             :          */
     794      803400 :         if (rte->securityQuals)
     795        2364 :             root->qual_security_level = Max(root->qual_security_level,
     796             :                                             list_length(rte->securityQuals));
     797             :     }
     798             : 
     799             :     /*
     800             :      * If we have now verified that the query target relation is
     801             :      * non-inheriting, mark it as a leaf target.
     802             :      */
     803      485698 :     if (parse->resultRelation)
     804             :     {
     805       88644 :         RangeTblEntry *rte = rt_fetch(parse->resultRelation, parse->rtable);
     806             : 
     807       88644 :         if (!rte->inh)
     808       86118 :             root->leaf_result_relids =
     809       86118 :                 bms_make_singleton(parse->resultRelation);
     810             :     }
     811             : 
     812             :     /*
     813             :      * Preprocess RowMark information.  We need to do this after subquery
     814             :      * pullup, so that all base relations are present.
     815             :      */
     816      485698 :     preprocess_rowmarks(root);
     817             : 
     818             :     /*
     819             :      * Set hasHavingQual to remember if HAVING clause is present.  Needed
     820             :      * because preprocess_expression will reduce a constant-true condition to
     821             :      * an empty qual list ... but "HAVING TRUE" is not a semantic no-op.
     822             :      */
     823      485698 :     root->hasHavingQual = (parse->havingQual != NULL);
     824             : 
     825             :     /*
     826             :      * Do expression preprocessing on targetlist and quals, as well as other
     827             :      * random expressions in the querytree.  Note that we do not need to
     828             :      * handle sort/group expressions explicitly, because they are actually
     829             :      * part of the targetlist.
     830             :      */
     831      482156 :     parse->targetList = (List *)
     832      485698 :         preprocess_expression(root, (Node *) parse->targetList,
     833             :                               EXPRKIND_TARGET);
     834             : 
     835             :     /* Constant-folding might have removed all set-returning functions */
     836      482156 :     if (parse->hasTargetSRFs)
     837        8340 :         parse->hasTargetSRFs = expression_returns_set((Node *) parse->targetList);
     838             : 
     839      482156 :     newWithCheckOptions = NIL;
     840      484476 :     foreach(l, parse->withCheckOptions)
     841             :     {
     842        2320 :         WithCheckOption *wco = lfirst_node(WithCheckOption, l);
     843             : 
     844        2320 :         wco->qual = preprocess_expression(root, wco->qual,
     845             :                                           EXPRKIND_QUAL);
     846        2320 :         if (wco->qual != NULL)
     847        1920 :             newWithCheckOptions = lappend(newWithCheckOptions, wco);
     848             :     }
     849      482156 :     parse->withCheckOptions = newWithCheckOptions;
     850             : 
     851      482156 :     parse->returningList = (List *)
     852      482156 :         preprocess_expression(root, (Node *) parse->returningList,
     853             :                               EXPRKIND_TARGET);
     854             : 
     855      482156 :     preprocess_qual_conditions(root, (Node *) parse->jointree);
     856             : 
     857      482156 :     parse->havingQual = preprocess_expression(root, parse->havingQual,
     858             :                                               EXPRKIND_QUAL);
     859             : 
     860      484672 :     foreach(l, parse->windowClause)
     861             :     {
     862        2516 :         WindowClause *wc = lfirst_node(WindowClause, l);
     863             : 
     864             :         /* partitionClause/orderClause are sort/group expressions */
     865        2516 :         wc->startOffset = preprocess_expression(root, wc->startOffset,
     866             :                                                 EXPRKIND_LIMIT);
     867        2516 :         wc->endOffset = preprocess_expression(root, wc->endOffset,
     868             :                                               EXPRKIND_LIMIT);
     869        2516 :         wc->runCondition = (List *) preprocess_expression(root,
     870        2516 :                                                           (Node *) wc->runCondition,
     871             :                                                           EXPRKIND_TARGET);
     872             :     }
     873             : 
     874      482156 :     parse->limitOffset = preprocess_expression(root, parse->limitOffset,
     875             :                                                EXPRKIND_LIMIT);
     876      482156 :     parse->limitCount = preprocess_expression(root, parse->limitCount,
     877             :                                               EXPRKIND_LIMIT);
     878             : 
     879      482156 :     if (parse->onConflict)
     880             :     {
     881        2860 :         parse->onConflict->arbiterElems = (List *)
     882        1430 :             preprocess_expression(root,
     883        1430 :                                   (Node *) parse->onConflict->arbiterElems,
     884             :                                   EXPRKIND_ARBITER_ELEM);
     885        2860 :         parse->onConflict->arbiterWhere =
     886        1430 :             preprocess_expression(root,
     887        1430 :                                   parse->onConflict->arbiterWhere,
     888             :                                   EXPRKIND_QUAL);
     889        2860 :         parse->onConflict->onConflictSet = (List *)
     890        1430 :             preprocess_expression(root,
     891        1430 :                                   (Node *) parse->onConflict->onConflictSet,
     892             :                                   EXPRKIND_TARGET);
     893        1430 :         parse->onConflict->onConflictWhere =
     894        1430 :             preprocess_expression(root,
     895        1430 :                                   parse->onConflict->onConflictWhere,
     896             :                                   EXPRKIND_QUAL);
     897             :         /* exclRelTlist contains only Vars, so no preprocessing needed */
     898             :     }
     899             : 
     900      484564 :     foreach(l, parse->mergeActionList)
     901             :     {
     902        2408 :         MergeAction *action = (MergeAction *) lfirst(l);
     903             : 
     904        2408 :         action->targetList = (List *)
     905        2408 :             preprocess_expression(root,
     906        2408 :                                   (Node *) action->targetList,
     907             :                                   EXPRKIND_TARGET);
     908        2408 :         action->qual =
     909        2408 :             preprocess_expression(root,
     910             :                                   (Node *) action->qual,
     911             :                                   EXPRKIND_QUAL);
     912             :     }
     913             : 
     914      482156 :     root->append_rel_list = (List *)
     915      482156 :         preprocess_expression(root, (Node *) root->append_rel_list,
     916             :                               EXPRKIND_APPINFO);
     917             : 
     918             :     /* Also need to preprocess expressions within RTEs */
     919     1281748 :     foreach(l, parse->rtable)
     920             :     {
     921      799592 :         RangeTblEntry *rte = lfirst_node(RangeTblEntry, l);
     922             :         int         kind;
     923             :         ListCell   *lcsq;
     924             : 
     925      799592 :         if (rte->rtekind == RTE_RELATION)
     926             :         {
     927      414728 :             if (rte->tablesample)
     928         222 :                 rte->tablesample = (TableSampleClause *)
     929         222 :                     preprocess_expression(root,
     930         222 :                                           (Node *) rte->tablesample,
     931             :                                           EXPRKIND_TABLESAMPLE);
     932             :         }
     933      384864 :         else if (rte->rtekind == RTE_SUBQUERY)
     934             :         {
     935             :             /*
     936             :              * We don't want to do all preprocessing yet on the subquery's
     937             :              * expressions, since that will happen when we plan it.  But if it
     938             :              * contains any join aliases of our level, those have to get
     939             :              * expanded now, because planning of the subquery won't do it.
     940             :              * That's only possible if the subquery is LATERAL.
     941             :              */
     942       51726 :             if (rte->lateral && root->hasJoinRTEs)
     943         854 :                 rte->subquery = (Query *)
     944         854 :                     flatten_join_alias_vars(root, root->parse,
     945         854 :                                             (Node *) rte->subquery);
     946             :         }
     947      333138 :         else if (rte->rtekind == RTE_FUNCTION)
     948             :         {
     949             :             /* Preprocess the function expression(s) fully */
     950       39778 :             kind = rte->lateral ? EXPRKIND_RTFUNC_LATERAL : EXPRKIND_RTFUNC;
     951       39778 :             rte->functions = (List *)
     952       39778 :                 preprocess_expression(root, (Node *) rte->functions, kind);
     953             :         }
     954      293360 :         else if (rte->rtekind == RTE_TABLEFUNC)
     955             :         {
     956             :             /* Preprocess the function expression(s) fully */
     957         222 :             kind = rte->lateral ? EXPRKIND_TABLEFUNC_LATERAL : EXPRKIND_TABLEFUNC;
     958         222 :             rte->tablefunc = (TableFunc *)
     959         222 :                 preprocess_expression(root, (Node *) rte->tablefunc, kind);
     960             :         }
     961      293138 :         else if (rte->rtekind == RTE_VALUES)
     962             :         {
     963             :             /* Preprocess the values lists fully */
     964        7704 :             kind = rte->lateral ? EXPRKIND_VALUES_LATERAL : EXPRKIND_VALUES;
     965        7704 :             rte->values_lists = (List *)
     966        7704 :                 preprocess_expression(root, (Node *) rte->values_lists, kind);
     967             :         }
     968             : 
     969             :         /*
     970             :          * Process each element of the securityQuals list as if it were a
     971             :          * separate qual expression (as indeed it is).  We need to do it this
     972             :          * way to get proper canonicalization of AND/OR structure.  Note that
     973             :          * this converts each element into an implicit-AND sublist.
     974             :          */
     975      802302 :         foreach(lcsq, rte->securityQuals)
     976             :         {
     977        2710 :             lfirst(lcsq) = preprocess_expression(root,
     978        2710 :                                                  (Node *) lfirst(lcsq),
     979             :                                                  EXPRKIND_QUAL);
     980             :         }
     981             :     }
     982             : 
     983             :     /*
     984             :      * Now that we are done preprocessing expressions, and in particular done
     985             :      * flattening join alias variables, get rid of the joinaliasvars lists.
     986             :      * They no longer match what expressions in the rest of the tree look
     987             :      * like, because we have not preprocessed expressions in those lists (and
     988             :      * do not want to; for example, expanding a SubLink there would result in
     989             :      * a useless unreferenced subplan).  Leaving them in place simply creates
     990             :      * a hazard for later scans of the tree.  We could try to prevent that by
     991             :      * using QTW_IGNORE_JOINALIASES in every tree scan done after this point,
     992             :      * but that doesn't sound very reliable.
     993             :      */
     994      482156 :     if (root->hasJoinRTEs)
     995             :     {
     996      257246 :         foreach(l, parse->rtable)
     997             :         {
     998      212296 :             RangeTblEntry *rte = lfirst_node(RangeTblEntry, l);
     999             : 
    1000      212296 :             rte->joinaliasvars = NIL;
    1001             :         }
    1002             :     }
    1003             : 
    1004             :     /*
    1005             :      * In some cases we may want to transfer a HAVING clause into WHERE. We
    1006             :      * cannot do so if the HAVING clause contains aggregates (obviously) or
    1007             :      * volatile functions (since a HAVING clause is supposed to be executed
    1008             :      * only once per group).  We also can't do this if there are any nonempty
    1009             :      * grouping sets; moving such a clause into WHERE would potentially change
    1010             :      * the results, if any referenced column isn't present in all the grouping
    1011             :      * sets.  (If there are only empty grouping sets, then the HAVING clause
    1012             :      * must be degenerate as discussed below.)
    1013             :      *
    1014             :      * Also, it may be that the clause is so expensive to execute that we're
    1015             :      * better off doing it only once per group, despite the loss of
    1016             :      * selectivity.  This is hard to estimate short of doing the entire
    1017             :      * planning process twice, so we use a heuristic: clauses containing
    1018             :      * subplans are left in HAVING.  Otherwise, we move or copy the HAVING
    1019             :      * clause into WHERE, in hopes of eliminating tuples before aggregation
    1020             :      * instead of after.
    1021             :      *
    1022             :      * If the query has explicit grouping then we can simply move such a
    1023             :      * clause into WHERE; any group that fails the clause will not be in the
    1024             :      * output because none of its tuples will reach the grouping or
    1025             :      * aggregation stage.  Otherwise we must have a degenerate (variable-free)
    1026             :      * HAVING clause, which we put in WHERE so that query_planner() can use it
    1027             :      * in a gating Result node, but also keep in HAVING to ensure that we
    1028             :      * don't emit a bogus aggregated row. (This could be done better, but it
    1029             :      * seems not worth optimizing.)
    1030             :      *
    1031             :      * Note that both havingQual and parse->jointree->quals are in
    1032             :      * implicitly-ANDed-list form at this point, even though they are declared
    1033             :      * as Node *.
    1034             :      */
    1035      482156 :     newHaving = NIL;
    1036      483298 :     foreach(l, (List *) parse->havingQual)
    1037             :     {
    1038        1142 :         Node       *havingclause = (Node *) lfirst(l);
    1039             : 
    1040        2242 :         if ((parse->groupClause && parse->groupingSets) ||
    1041        1242 :             contain_agg_clause(havingclause) ||
    1042         284 :             contain_volatile_functions(havingclause) ||
    1043         142 :             contain_subplans(havingclause))
    1044             :         {
    1045             :             /* keep it in HAVING */
    1046        1000 :             newHaving = lappend(newHaving, havingclause);
    1047             :         }
    1048         142 :         else if (parse->groupClause && !parse->groupingSets)
    1049             :         {
    1050             :             /* move it to WHERE */
    1051         124 :             parse->jointree->quals = (Node *)
    1052         124 :                 lappend((List *) parse->jointree->quals, havingclause);
    1053             :         }
    1054             :         else
    1055             :         {
    1056             :             /* put a copy in WHERE, keep it in HAVING */
    1057          36 :             parse->jointree->quals = (Node *)
    1058          18 :                 lappend((List *) parse->jointree->quals,
    1059             :                         copyObject(havingclause));
    1060          18 :             newHaving = lappend(newHaving, havingclause);
    1061             :         }
    1062             :     }
    1063      482156 :     parse->havingQual = (Node *) newHaving;
    1064             : 
    1065             :     /*
    1066             :      * If we have any outer joins, try to reduce them to plain inner joins.
    1067             :      * This step is most easily done after we've done expression
    1068             :      * preprocessing.
    1069             :      */
    1070      482156 :     if (hasOuterJoins)
    1071       29174 :         reduce_outer_joins(root);
    1072             : 
    1073             :     /*
    1074             :      * If we have any RTE_RESULT relations, see if they can be deleted from
    1075             :      * the jointree.  We also rely on this processing to flatten single-child
    1076             :      * FromExprs underneath outer joins.  This step is most effectively done
    1077             :      * after we've done expression preprocessing and outer join reduction.
    1078             :      */
    1079      482156 :     if (hasResultRTEs || hasOuterJoins)
    1080      234048 :         remove_useless_result_rtes(root);
    1081             : 
    1082             :     /*
    1083             :      * Do the main planning.
    1084             :      */
    1085      482156 :     grouping_planner(root, tuple_fraction);
    1086             : 
    1087             :     /*
    1088             :      * Capture the set of outer-level param IDs we have access to, for use in
    1089             :      * extParam/allParam calculations later.
    1090             :      */
    1091      482092 :     SS_identify_outer_params(root);
    1092             : 
    1093             :     /*
    1094             :      * If any initPlans were created in this query level, adjust the surviving
    1095             :      * Paths' costs and parallel-safety flags to account for them.  The
    1096             :      * initPlans won't actually get attached to the plan tree till
    1097             :      * create_plan() runs, but we must include their effects now.
    1098             :      */
    1099      482092 :     final_rel = fetch_upper_rel(root, UPPERREL_FINAL, NULL);
    1100      482092 :     SS_charge_for_initplans(root, final_rel);
    1101             : 
    1102             :     /*
    1103             :      * Make sure we've identified the cheapest Path for the final rel.  (By
    1104             :      * doing this here not in grouping_planner, we include initPlan costs in
    1105             :      * the decision, though it's unlikely that will change anything.)
    1106             :      */
    1107      482092 :     set_cheapest(final_rel);
    1108             : 
    1109      482092 :     return root;
    1110             : }
    1111             : 
    1112             : /*
    1113             :  * preprocess_expression
    1114             :  *      Do subquery_planner's preprocessing work for an expression,
    1115             :  *      which can be a targetlist, a WHERE clause (including JOIN/ON
    1116             :  *      conditions), a HAVING clause, or a few other things.
    1117             :  */
    1118             : static Node *
    1119     3538432 : preprocess_expression(PlannerInfo *root, Node *expr, int kind)
    1120             : {
    1121             :     /*
    1122             :      * Fall out quickly if expression is empty.  This occurs often enough to
    1123             :      * be worth checking.  Note that null->null is the correct conversion for
    1124             :      * implicit-AND result format, too.
    1125             :      */
    1126     3538432 :     if (expr == NULL)
    1127     2731314 :         return NULL;
    1128             : 
    1129             :     /*
    1130             :      * If the query has any join RTEs, replace join alias variables with
    1131             :      * base-relation variables.  We must do this first, since any expressions
    1132             :      * we may extract from the joinaliasvars lists have not been preprocessed.
    1133             :      * For example, if we did this after sublink processing, sublinks expanded
    1134             :      * out from join aliases would not get processed.  But we can skip this in
    1135             :      * non-lateral RTE functions, VALUES lists, and TABLESAMPLE clauses, since
    1136             :      * they can't contain any Vars of the current query level.
    1137             :      */
    1138      807118 :     if (root->hasJoinRTEs &&
    1139      324060 :         !(kind == EXPRKIND_RTFUNC ||
    1140      161844 :           kind == EXPRKIND_VALUES ||
    1141             :           kind == EXPRKIND_TABLESAMPLE ||
    1142             :           kind == EXPRKIND_TABLEFUNC))
    1143      161832 :         expr = flatten_join_alias_vars(root, root->parse, expr);
    1144             : 
    1145             :     /*
    1146             :      * Simplify constant expressions.  For function RTEs, this was already
    1147             :      * done by preprocess_function_rtes.  (But note we must do it again for
    1148             :      * EXPRKIND_RTFUNC_LATERAL, because those might by now contain
    1149             :      * un-simplified subexpressions inserted by flattening of subqueries or
    1150             :      * join alias variables.)
    1151             :      *
    1152             :      * Note: an essential effect of this is to convert named-argument function
    1153             :      * calls to positional notation and insert the current actual values of
    1154             :      * any default arguments for functions.  To ensure that happens, we *must*
    1155             :      * process all expressions here.  Previous PG versions sometimes skipped
    1156             :      * const-simplification if it didn't seem worth the trouble, but we can't
    1157             :      * do that anymore.
    1158             :      *
    1159             :      * Note: this also flattens nested AND and OR expressions into N-argument
    1160             :      * form.  All processing of a qual expression after this point must be
    1161             :      * careful to maintain AND/OR flatness --- that is, do not generate a tree
    1162             :      * with AND directly under AND, nor OR directly under OR.
    1163             :      */
    1164      807118 :     if (kind != EXPRKIND_RTFUNC)
    1165      775518 :         expr = eval_const_expressions(root, expr);
    1166             : 
    1167             :     /*
    1168             :      * If it's a qual or havingQual, canonicalize it.
    1169             :      */
    1170      803576 :     if (kind == EXPRKIND_QUAL)
    1171             :     {
    1172      276344 :         expr = (Node *) canonicalize_qual((Expr *) expr, false);
    1173             : 
    1174             : #ifdef OPTIMIZER_DEBUG
    1175             :         printf("After canonicalize_qual()\n");
    1176             :         pprint(expr);
    1177             : #endif
    1178             :     }
    1179             : 
    1180             :     /*
    1181             :      * Check for ANY ScalarArrayOpExpr with Const arrays and set the
    1182             :      * hashfuncid of any that might execute more quickly by using hash lookups
    1183             :      * instead of a linear search.
    1184             :      */
    1185      803576 :     if (kind == EXPRKIND_QUAL || kind == EXPRKIND_TARGET)
    1186             :     {
    1187      745896 :         convert_saop_to_hashed_saop(expr);
    1188             :     }
    1189             : 
    1190             :     /* Expand SubLinks to SubPlans */
    1191      803576 :     if (root->parse->hasSubLinks)
    1192       76788 :         expr = SS_process_sublinks(root, expr, (kind == EXPRKIND_QUAL));
    1193             : 
    1194             :     /*
    1195             :      * XXX do not insert anything here unless you have grokked the comments in
    1196             :      * SS_replace_correlation_vars ...
    1197             :      */
    1198             : 
    1199             :     /* Replace uplevel vars with Param nodes (this IS possible in VALUES) */
    1200      803576 :     if (root->query_level > 1)
    1201      125264 :         expr = SS_replace_correlation_vars(root, expr);
    1202             : 
    1203             :     /*
    1204             :      * If it's a qual or havingQual, convert it to implicit-AND format. (We
    1205             :      * don't want to do this before eval_const_expressions, since the latter
    1206             :      * would be unable to simplify a top-level AND correctly. Also,
    1207             :      * SS_process_sublinks expects explicit-AND format.)
    1208             :      */
    1209      803576 :     if (kind == EXPRKIND_QUAL)
    1210      276344 :         expr = (Node *) make_ands_implicit((Expr *) expr);
    1211             : 
    1212      803576 :     return expr;
    1213             : }
    1214             : 
    1215             : /*
    1216             :  * preprocess_qual_conditions
    1217             :  *      Recursively scan the query's jointree and do subquery_planner's
    1218             :  *      preprocessing work on each qual condition found therein.
    1219             :  */
    1220             : static void
    1221     1171540 : preprocess_qual_conditions(PlannerInfo *root, Node *jtnode)
    1222             : {
    1223     1171540 :     if (jtnode == NULL)
    1224           0 :         return;
    1225     1171540 :     if (IsA(jtnode, RangeTblRef))
    1226             :     {
    1227             :         /* nothing to do here */
    1228             :     }
    1229      570842 :     else if (IsA(jtnode, FromExpr))
    1230             :     {
    1231      491350 :         FromExpr   *f = (FromExpr *) jtnode;
    1232             :         ListCell   *l;
    1233             : 
    1234     1021750 :         foreach(l, f->fromlist)
    1235      530400 :             preprocess_qual_conditions(root, lfirst(l));
    1236             : 
    1237      491350 :         f->quals = preprocess_expression(root, f->quals, EXPRKIND_QUAL);
    1238             :     }
    1239       79492 :     else if (IsA(jtnode, JoinExpr))
    1240             :     {
    1241       79492 :         JoinExpr   *j = (JoinExpr *) jtnode;
    1242             : 
    1243       79492 :         preprocess_qual_conditions(root, j->larg);
    1244       79492 :         preprocess_qual_conditions(root, j->rarg);
    1245             : 
    1246       79492 :         j->quals = preprocess_expression(root, j->quals, EXPRKIND_QUAL);
    1247             :     }
    1248             :     else
    1249           0 :         elog(ERROR, "unrecognized node type: %d",
    1250             :              (int) nodeTag(jtnode));
    1251             : }
    1252             : 
    1253             : /*
    1254             :  * preprocess_phv_expression
    1255             :  *    Do preprocessing on a PlaceHolderVar expression that's been pulled up.
    1256             :  *
    1257             :  * If a LATERAL subquery references an output of another subquery, and that
    1258             :  * output must be wrapped in a PlaceHolderVar because of an intermediate outer
    1259             :  * join, then we'll push the PlaceHolderVar expression down into the subquery
    1260             :  * and later pull it back up during find_lateral_references, which runs after
    1261             :  * subquery_planner has preprocessed all the expressions that were in the
    1262             :  * current query level to start with.  So we need to preprocess it then.
    1263             :  */
    1264             : Expr *
    1265          72 : preprocess_phv_expression(PlannerInfo *root, Expr *expr)
    1266             : {
    1267          72 :     return (Expr *) preprocess_expression(root, (Node *) expr, EXPRKIND_PHV);
    1268             : }
    1269             : 
    1270             : /*--------------------
    1271             :  * grouping_planner
    1272             :  *    Perform planning steps related to grouping, aggregation, etc.
    1273             :  *
    1274             :  * This function adds all required top-level processing to the scan/join
    1275             :  * Path(s) produced by query_planner.
    1276             :  *
    1277             :  * tuple_fraction is the fraction of tuples we expect will be retrieved.
    1278             :  * tuple_fraction is interpreted as follows:
    1279             :  *    0: expect all tuples to be retrieved (normal case)
    1280             :  *    0 < tuple_fraction < 1: expect the given fraction of tuples available
    1281             :  *      from the plan to be retrieved
    1282             :  *    tuple_fraction >= 1: tuple_fraction is the absolute number of tuples
    1283             :  *      expected to be retrieved (ie, a LIMIT specification)
    1284             :  *
    1285             :  * Returns nothing; the useful output is in the Paths we attach to the
    1286             :  * (UPPERREL_FINAL, NULL) upperrel in *root.  In addition,
    1287             :  * root->processed_tlist contains the final processed targetlist.
    1288             :  *
    1289             :  * Note that we have not done set_cheapest() on the final rel; it's convenient
    1290             :  * to leave this to the caller.
    1291             :  *--------------------
    1292             :  */
    1293             : static void
    1294      482156 : grouping_planner(PlannerInfo *root, double tuple_fraction)
    1295             : {
    1296      482156 :     Query      *parse = root->parse;
    1297      482156 :     int64       offset_est = 0;
    1298      482156 :     int64       count_est = 0;
    1299      482156 :     double      limit_tuples = -1.0;
    1300      482156 :     bool        have_postponed_srfs = false;
    1301             :     PathTarget *final_target;
    1302             :     List       *final_targets;
    1303             :     List       *final_targets_contain_srfs;
    1304             :     bool        final_target_parallel_safe;
    1305             :     RelOptInfo *current_rel;
    1306             :     RelOptInfo *final_rel;
    1307             :     FinalPathExtraData extra;
    1308             :     ListCell   *lc;
    1309             : 
    1310             :     /* Tweak caller-supplied tuple_fraction if have LIMIT/OFFSET */
    1311      482156 :     if (parse->limitCount || parse->limitOffset)
    1312             :     {
    1313        4650 :         tuple_fraction = preprocess_limit(root, tuple_fraction,
    1314             :                                           &offset_est, &count_est);
    1315             : 
    1316             :         /*
    1317             :          * If we have a known LIMIT, and don't have an unknown OFFSET, we can
    1318             :          * estimate the effects of using a bounded sort.
    1319             :          */
    1320        4650 :         if (count_est > 0 && offset_est >= 0)
    1321        4168 :             limit_tuples = (double) count_est + (double) offset_est;
    1322             :     }
    1323             : 
    1324             :     /* Make tuple_fraction accessible to lower-level routines */
    1325      482156 :     root->tuple_fraction = tuple_fraction;
    1326             : 
    1327      482156 :     if (parse->setOperations)
    1328             :     {
    1329             :         /*
    1330             :          * If there's a top-level ORDER BY, assume we have to fetch all the
    1331             :          * tuples.  This might be too simplistic given all the hackery below
    1332             :          * to possibly avoid the sort; but the odds of accurate estimates here
    1333             :          * are pretty low anyway.  XXX try to get rid of this in favor of
    1334             :          * letting plan_set_operations generate both fast-start and
    1335             :          * cheapest-total paths.
    1336             :          */
    1337        5158 :         if (parse->sortClause)
    1338        3352 :             root->tuple_fraction = 0.0;
    1339             : 
    1340             :         /*
    1341             :          * Construct Paths for set operations.  The results will not need any
    1342             :          * work except perhaps a top-level sort and/or LIMIT.  Note that any
    1343             :          * special work for recursive unions is the responsibility of
    1344             :          * plan_set_operations.
    1345             :          */
    1346        5158 :         current_rel = plan_set_operations(root);
    1347             : 
    1348             :         /*
    1349             :          * We should not need to call preprocess_targetlist, since we must be
    1350             :          * in a SELECT query node.  Instead, use the processed_tlist returned
    1351             :          * by plan_set_operations (since this tells whether it returned any
    1352             :          * resjunk columns!), and transfer any sort key information from the
    1353             :          * original tlist.
    1354             :          */
    1355             :         Assert(parse->commandType == CMD_SELECT);
    1356             : 
    1357             :         /* for safety, copy processed_tlist instead of modifying in-place */
    1358        5152 :         root->processed_tlist =
    1359        5152 :             postprocess_setop_tlist(copyObject(root->processed_tlist),
    1360             :                                     parse->targetList);
    1361             : 
    1362             :         /* Also extract the PathTarget form of the setop result tlist */
    1363        5152 :         final_target = current_rel->cheapest_total_path->pathtarget;
    1364             : 
    1365             :         /* And check whether it's parallel safe */
    1366             :         final_target_parallel_safe =
    1367        5152 :             is_parallel_safe(root, (Node *) final_target->exprs);
    1368             : 
    1369             :         /* The setop result tlist couldn't contain any SRFs */
    1370             :         Assert(!parse->hasTargetSRFs);
    1371        5152 :         final_targets = final_targets_contain_srfs = NIL;
    1372             : 
    1373             :         /*
    1374             :          * Can't handle FOR [KEY] UPDATE/SHARE here (parser should have
    1375             :          * checked already, but let's make sure).
    1376             :          */
    1377        5152 :         if (parse->rowMarks)
    1378           0 :             ereport(ERROR,
    1379             :                     (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
    1380             :             /*------
    1381             :               translator: %s is a SQL row locking clause such as FOR UPDATE */
    1382             :                      errmsg("%s is not allowed with UNION/INTERSECT/EXCEPT",
    1383             :                             LCS_asString(linitial_node(RowMarkClause,
    1384             :                                                        parse->rowMarks)->strength))));
    1385             : 
    1386             :         /*
    1387             :          * Calculate pathkeys that represent result ordering requirements
    1388             :          */
    1389             :         Assert(parse->distinctClause == NIL);
    1390        5152 :         root->sort_pathkeys = make_pathkeys_for_sortclauses(root,
    1391             :                                                             parse->sortClause,
    1392             :                                                             root->processed_tlist);
    1393             :     }
    1394             :     else
    1395             :     {
    1396             :         /* No set operations, do regular planning */
    1397             :         PathTarget *sort_input_target;
    1398             :         List       *sort_input_targets;
    1399             :         List       *sort_input_targets_contain_srfs;
    1400             :         bool        sort_input_target_parallel_safe;
    1401             :         PathTarget *grouping_target;
    1402             :         List       *grouping_targets;
    1403             :         List       *grouping_targets_contain_srfs;
    1404             :         bool        grouping_target_parallel_safe;
    1405             :         PathTarget *scanjoin_target;
    1406             :         List       *scanjoin_targets;
    1407             :         List       *scanjoin_targets_contain_srfs;
    1408             :         bool        scanjoin_target_parallel_safe;
    1409             :         bool        scanjoin_target_same_exprs;
    1410             :         bool        have_grouping;
    1411      476998 :         WindowFuncLists *wflists = NULL;
    1412      476998 :         List       *activeWindows = NIL;
    1413      476998 :         grouping_sets_data *gset_data = NULL;
    1414             :         standard_qp_extra qp_extra;
    1415             : 
    1416             :         /* A recursive query should always have setOperations */
    1417             :         Assert(!root->hasRecursion);
    1418             : 
    1419             :         /* Preprocess grouping sets and GROUP BY clause, if any */
    1420      476998 :         if (parse->groupingSets)
    1421             :         {
    1422         734 :             gset_data = preprocess_grouping_sets(root);
    1423             :         }
    1424      476264 :         else if (parse->groupClause)
    1425             :         {
    1426             :             /* Preprocess regular GROUP BY clause, if any */
    1427        3366 :             root->processed_groupClause = list_copy(parse->groupClause);
    1428             :             /* Remove any redundant GROUP BY columns */
    1429        3366 :             remove_useless_groupby_columns(root);
    1430             :         }
    1431             : 
    1432             :         /*
    1433             :          * Preprocess targetlist.  Note that much of the remaining planning
    1434             :          * work will be done with the PathTarget representation of tlists, but
    1435             :          * we must also maintain the full representation of the final tlist so
    1436             :          * that we can transfer its decoration (resnames etc) to the topmost
    1437             :          * tlist of the finished Plan.  This is kept in processed_tlist.
    1438             :          */
    1439      476992 :         preprocess_targetlist(root);
    1440             : 
    1441             :         /*
    1442             :          * Mark all the aggregates with resolved aggtranstypes, and detect
    1443             :          * aggregates that are duplicates or can share transition state.  We
    1444             :          * must do this before slicing and dicing the tlist into various
    1445             :          * pathtargets, else some copies of the Aggref nodes might escape
    1446             :          * being marked.
    1447             :          */
    1448      476992 :         if (parse->hasAggs)
    1449             :         {
    1450       33544 :             preprocess_aggrefs(root, (Node *) root->processed_tlist);
    1451       33544 :             preprocess_aggrefs(root, (Node *) parse->havingQual);
    1452             :         }
    1453             : 
    1454             :         /*
    1455             :          * Locate any window functions in the tlist.  (We don't need to look
    1456             :          * anywhere else, since expressions used in ORDER BY will be in there
    1457             :          * too.)  Note that they could all have been eliminated by constant
    1458             :          * folding, in which case we don't need to do any more work.
    1459             :          */
    1460      476992 :         if (parse->hasWindowFuncs)
    1461             :         {
    1462        2300 :             wflists = find_window_functions((Node *) root->processed_tlist,
    1463        2300 :                                             list_length(parse->windowClause));
    1464        2300 :             if (wflists->numWindowFuncs > 0)
    1465             :             {
    1466             :                 /*
    1467             :                  * See if any modifications can be made to each WindowClause
    1468             :                  * to allow the executor to execute the WindowFuncs more
    1469             :                  * quickly.
    1470             :                  */
    1471        2294 :                 optimize_window_clauses(root, wflists);
    1472             : 
    1473        2294 :                 activeWindows = select_active_windows(root, wflists);
    1474             :             }
    1475             :             else
    1476           6 :                 parse->hasWindowFuncs = false;
    1477             :         }
    1478             : 
    1479             :         /*
    1480             :          * Preprocess MIN/MAX aggregates, if any.  Note: be careful about
    1481             :          * adding logic between here and the query_planner() call.  Anything
    1482             :          * that is needed in MIN/MAX-optimizable cases will have to be
    1483             :          * duplicated in planagg.c.
    1484             :          */
    1485      476992 :         if (parse->hasAggs)
    1486       33544 :             preprocess_minmax_aggregates(root);
    1487             : 
    1488             :         /*
    1489             :          * Figure out whether there's a hard limit on the number of rows that
    1490             :          * query_planner's result subplan needs to return.  Even if we know a
    1491             :          * hard limit overall, it doesn't apply if the query has any
    1492             :          * grouping/aggregation operations, or SRFs in the tlist.
    1493             :          */
    1494      476992 :         if (parse->groupClause ||
    1495      472940 :             parse->groupingSets ||
    1496      472898 :             parse->distinctClause ||
    1497      470726 :             parse->hasAggs ||
    1498      440838 :             parse->hasWindowFuncs ||
    1499      438670 :             parse->hasTargetSRFs ||
    1500      430756 :             root->hasHavingQual)
    1501       46254 :             root->limit_tuples = -1.0;
    1502             :         else
    1503      430738 :             root->limit_tuples = limit_tuples;
    1504             : 
    1505             :         /* Set up data needed by standard_qp_callback */
    1506      476992 :         qp_extra.activeWindows = activeWindows;
    1507      476992 :         qp_extra.gset_data = gset_data;
    1508             : 
    1509             :         /*
    1510             :          * Check if we're a subquery for a set operation.  If we are, store
    1511             :          * the SetOperationStmt in qp_extra.
    1512             :          */
    1513      476992 :         if (root->parent_root != NULL &&
    1514       55334 :             root->parent_root->parse->setOperations != NULL &&
    1515       13784 :             IsA(root->parent_root->parse->setOperations, SetOperationStmt))
    1516       13784 :             qp_extra.setop =
    1517       13784 :                 (SetOperationStmt *) root->parent_root->parse->setOperations;
    1518             :         else
    1519      463208 :             qp_extra.setop = NULL;
    1520             : 
    1521             :         /*
    1522             :          * Generate the best unsorted and presorted paths for the scan/join
    1523             :          * portion of this Query, ie the processing represented by the
    1524             :          * FROM/WHERE clauses.  (Note there may not be any presorted paths.)
    1525             :          * We also generate (in standard_qp_callback) pathkey representations
    1526             :          * of the query's sort clause, distinct clause, etc.
    1527             :          */
    1528      476992 :         current_rel = query_planner(root, standard_qp_callback, &qp_extra);
    1529             : 
    1530             :         /*
    1531             :          * Convert the query's result tlist into PathTarget format.
    1532             :          *
    1533             :          * Note: this cannot be done before query_planner() has performed
    1534             :          * appendrel expansion, because that might add resjunk entries to
    1535             :          * root->processed_tlist.  Waiting till afterwards is also helpful
    1536             :          * because the target width estimates can use per-Var width numbers
    1537             :          * that were obtained within query_planner().
    1538             :          */
    1539      476948 :         final_target = create_pathtarget(root, root->processed_tlist);
    1540             :         final_target_parallel_safe =
    1541      476948 :             is_parallel_safe(root, (Node *) final_target->exprs);
    1542             : 
    1543             :         /*
    1544             :          * If ORDER BY was given, consider whether we should use a post-sort
    1545             :          * projection, and compute the adjusted target for preceding steps if
    1546             :          * so.
    1547             :          */
    1548      476948 :         if (parse->sortClause)
    1549             :         {
    1550       53510 :             sort_input_target = make_sort_input_target(root,
    1551             :                                                        final_target,
    1552             :                                                        &have_postponed_srfs);
    1553             :             sort_input_target_parallel_safe =
    1554       53510 :                 is_parallel_safe(root, (Node *) sort_input_target->exprs);
    1555             :         }
    1556             :         else
    1557             :         {
    1558      423438 :             sort_input_target = final_target;
    1559      423438 :             sort_input_target_parallel_safe = final_target_parallel_safe;
    1560             :         }
    1561             : 
    1562             :         /*
    1563             :          * If we have window functions to deal with, the output from any
    1564             :          * grouping step needs to be what the window functions want;
    1565             :          * otherwise, it should be sort_input_target.
    1566             :          */
    1567      476948 :         if (activeWindows)
    1568             :         {
    1569        2294 :             grouping_target = make_window_input_target(root,
    1570             :                                                        final_target,
    1571             :                                                        activeWindows);
    1572             :             grouping_target_parallel_safe =
    1573        2294 :                 is_parallel_safe(root, (Node *) grouping_target->exprs);
    1574             :         }
    1575             :         else
    1576             :         {
    1577      474654 :             grouping_target = sort_input_target;
    1578      474654 :             grouping_target_parallel_safe = sort_input_target_parallel_safe;
    1579             :         }
    1580             : 
    1581             :         /*
    1582             :          * If we have grouping or aggregation to do, the topmost scan/join
    1583             :          * plan node must emit what the grouping step wants; otherwise, it
    1584             :          * should emit grouping_target.
    1585             :          */
    1586      472896 :         have_grouping = (parse->groupClause || parse->groupingSets ||
    1587      949844 :                          parse->hasAggs || root->hasHavingQual);
    1588      476948 :         if (have_grouping)
    1589             :         {
    1590       34026 :             scanjoin_target = make_group_input_target(root, final_target);
    1591             :             scanjoin_target_parallel_safe =
    1592       34026 :                 is_parallel_safe(root, (Node *) scanjoin_target->exprs);
    1593             :         }
    1594             :         else
    1595             :         {
    1596      442922 :             scanjoin_target = grouping_target;
    1597      442922 :             scanjoin_target_parallel_safe = grouping_target_parallel_safe;
    1598             :         }
    1599             : 
    1600             :         /*
    1601             :          * If there are any SRFs in the targetlist, we must separate each of
    1602             :          * these PathTargets into SRF-computing and SRF-free targets.  Replace
    1603             :          * each of the named targets with a SRF-free version, and remember the
    1604             :          * list of additional projection steps we need to add afterwards.
    1605             :          */
    1606      476948 :         if (parse->hasTargetSRFs)
    1607             :         {
    1608             :             /* final_target doesn't recompute any SRFs in sort_input_target */
    1609        8340 :             split_pathtarget_at_srfs(root, final_target, sort_input_target,
    1610             :                                      &final_targets,
    1611             :                                      &final_targets_contain_srfs);
    1612        8340 :             final_target = linitial_node(PathTarget, final_targets);
    1613             :             Assert(!linitial_int(final_targets_contain_srfs));
    1614             :             /* likewise for sort_input_target vs. grouping_target */
    1615        8340 :             split_pathtarget_at_srfs(root, sort_input_target, grouping_target,
    1616             :                                      &sort_input_targets,
    1617             :                                      &sort_input_targets_contain_srfs);
    1618        8340 :             sort_input_target = linitial_node(PathTarget, sort_input_targets);
    1619             :             Assert(!linitial_int(sort_input_targets_contain_srfs));
    1620             :             /* likewise for grouping_target vs. scanjoin_target */
    1621        8340 :             split_pathtarget_at_srfs(root, grouping_target, scanjoin_target,
    1622             :                                      &grouping_targets,
    1623             :                                      &grouping_targets_contain_srfs);
    1624        8340 :             grouping_target = linitial_node(PathTarget, grouping_targets);
    1625             :             Assert(!linitial_int(grouping_targets_contain_srfs));
    1626             :             /* scanjoin_target will not have any SRFs precomputed for it */
    1627        8340 :             split_pathtarget_at_srfs(root, scanjoin_target, NULL,
    1628             :                                      &scanjoin_targets,
    1629             :                                      &scanjoin_targets_contain_srfs);
    1630        8340 :             scanjoin_target = linitial_node(PathTarget, scanjoin_targets);
    1631             :             Assert(!linitial_int(scanjoin_targets_contain_srfs));
    1632             :         }
    1633             :         else
    1634             :         {
    1635             :             /* initialize lists; for most of these, dummy values are OK */
    1636      468608 :             final_targets = final_targets_contain_srfs = NIL;
    1637      468608 :             sort_input_targets = sort_input_targets_contain_srfs = NIL;
    1638      468608 :             grouping_targets = grouping_targets_contain_srfs = NIL;
    1639      468608 :             scanjoin_targets = list_make1(scanjoin_target);
    1640      468608 :             scanjoin_targets_contain_srfs = NIL;
    1641             :         }
    1642             : 
    1643             :         /* Apply scan/join target. */
    1644      476948 :         scanjoin_target_same_exprs = list_length(scanjoin_targets) == 1
    1645      476948 :             && equal(scanjoin_target->exprs, current_rel->reltarget->exprs);
    1646      476948 :         apply_scanjoin_target_to_paths(root, current_rel, scanjoin_targets,
    1647             :                                        scanjoin_targets_contain_srfs,
    1648             :                                        scanjoin_target_parallel_safe,
    1649             :                                        scanjoin_target_same_exprs);
    1650             : 
    1651             :         /*
    1652             :          * Save the various upper-rel PathTargets we just computed into
    1653             :          * root->upper_targets[].  The core code doesn't use this, but it
    1654             :          * provides a convenient place for extensions to get at the info.  For
    1655             :          * consistency, we save all the intermediate targets, even though some
    1656             :          * of the corresponding upperrels might not be needed for this query.
    1657             :          */
    1658      476948 :         root->upper_targets[UPPERREL_FINAL] = final_target;
    1659      476948 :         root->upper_targets[UPPERREL_ORDERED] = final_target;
    1660      476948 :         root->upper_targets[UPPERREL_DISTINCT] = sort_input_target;
    1661      476948 :         root->upper_targets[UPPERREL_PARTIAL_DISTINCT] = sort_input_target;
    1662      476948 :         root->upper_targets[UPPERREL_WINDOW] = sort_input_target;
    1663      476948 :         root->upper_targets[UPPERREL_GROUP_AGG] = grouping_target;
    1664             : 
    1665             :         /*
    1666             :          * If we have grouping and/or aggregation, consider ways to implement
    1667             :          * that.  We build a new upperrel representing the output of this
    1668             :          * phase.
    1669             :          */
    1670      476948 :         if (have_grouping)
    1671             :         {
    1672       34026 :             current_rel = create_grouping_paths(root,
    1673             :                                                 current_rel,
    1674             :                                                 grouping_target,
    1675             :                                                 grouping_target_parallel_safe,
    1676             :                                                 gset_data);
    1677             :             /* Fix things up if grouping_target contains SRFs */
    1678       34018 :             if (parse->hasTargetSRFs)
    1679         384 :                 adjust_paths_for_srfs(root, current_rel,
    1680             :                                       grouping_targets,
    1681             :                                       grouping_targets_contain_srfs);
    1682             :         }
    1683             : 
    1684             :         /*
    1685             :          * If we have window functions, consider ways to implement those.  We
    1686             :          * build a new upperrel representing the output of this phase.
    1687             :          */
    1688      476940 :         if (activeWindows)
    1689             :         {
    1690        2294 :             current_rel = create_window_paths(root,
    1691             :                                               current_rel,
    1692             :                                               grouping_target,
    1693             :                                               sort_input_target,
    1694             :                                               sort_input_target_parallel_safe,
    1695             :                                               wflists,
    1696             :                                               activeWindows);
    1697             :             /* Fix things up if sort_input_target contains SRFs */
    1698        2294 :             if (parse->hasTargetSRFs)
    1699          12 :                 adjust_paths_for_srfs(root, current_rel,
    1700             :                                       sort_input_targets,
    1701             :                                       sort_input_targets_contain_srfs);
    1702             :         }
    1703             : 
    1704             :         /*
    1705             :          * If there is a DISTINCT clause, consider ways to implement that. We
    1706             :          * build a new upperrel representing the output of this phase.
    1707             :          */
    1708      476940 :         if (parse->distinctClause)
    1709             :         {
    1710        2182 :             current_rel = create_distinct_paths(root,
    1711             :                                                 current_rel,
    1712             :                                                 sort_input_target);
    1713             :         }
    1714             :     }                           /* end of if (setOperations) */
    1715             : 
    1716             :     /*
    1717             :      * If ORDER BY was given, consider ways to implement that, and generate a
    1718             :      * new upperrel containing only paths that emit the correct ordering and
    1719             :      * project the correct final_target.  We can apply the original
    1720             :      * limit_tuples limit in sort costing here, but only if there are no
    1721             :      * postponed SRFs.
    1722             :      */
    1723      482092 :     if (parse->sortClause)
    1724             :     {
    1725       56862 :         current_rel = create_ordered_paths(root,
    1726             :                                            current_rel,
    1727             :                                            final_target,
    1728             :                                            final_target_parallel_safe,
    1729             :                                            have_postponed_srfs ? -1.0 :
    1730             :                                            limit_tuples);
    1731             :         /* Fix things up if final_target contains SRFs */
    1732       56862 :         if (parse->hasTargetSRFs)
    1733         196 :             adjust_paths_for_srfs(root, current_rel,
    1734             :                                   final_targets,
    1735             :                                   final_targets_contain_srfs);
    1736             :     }
    1737             : 
    1738             :     /*
    1739             :      * Now we are prepared to build the final-output upperrel.
    1740             :      */
    1741      482092 :     final_rel = fetch_upper_rel(root, UPPERREL_FINAL, NULL);
    1742             : 
    1743             :     /*
    1744             :      * If the input rel is marked consider_parallel and there's nothing that's
    1745             :      * not parallel-safe in the LIMIT clause, then the final_rel can be marked
    1746             :      * consider_parallel as well.  Note that if the query has rowMarks or is
    1747             :      * not a SELECT, consider_parallel will be false for every relation in the
    1748             :      * query.
    1749             :      */
    1750      626054 :     if (current_rel->consider_parallel &&
    1751      287900 :         is_parallel_safe(root, parse->limitOffset) &&
    1752      143938 :         is_parallel_safe(root, parse->limitCount))
    1753      143932 :         final_rel->consider_parallel = true;
    1754             : 
    1755             :     /*
    1756             :      * If the current_rel belongs to a single FDW, so does the final_rel.
    1757             :      */
    1758      482092 :     final_rel->serverid = current_rel->serverid;
    1759      482092 :     final_rel->userid = current_rel->userid;
    1760      482092 :     final_rel->useridiscurrent = current_rel->useridiscurrent;
    1761      482092 :     final_rel->fdwroutine = current_rel->fdwroutine;
    1762             : 
    1763             :     /*
    1764             :      * Generate paths for the final_rel.  Insert all surviving paths, with
    1765             :      * LockRows, Limit, and/or ModifyTable steps added if needed.
    1766             :      */
    1767      980714 :     foreach(lc, current_rel->pathlist)
    1768             :     {
    1769      498622 :         Path       *path = (Path *) lfirst(lc);
    1770             : 
    1771             :         /*
    1772             :          * If there is a FOR [KEY] UPDATE/SHARE clause, add the LockRows node.
    1773             :          * (Note: we intentionally test parse->rowMarks not root->rowMarks
    1774             :          * here.  If there are only non-locking rowmarks, they should be
    1775             :          * handled by the ModifyTable node instead.  However, root->rowMarks
    1776             :          * is what goes into the LockRows node.)
    1777             :          */
    1778      498622 :         if (parse->rowMarks)
    1779             :         {
    1780        7946 :             path = (Path *) create_lockrows_path(root, final_rel, path,
    1781             :                                                  root->rowMarks,
    1782             :                                                  assign_special_exec_param(root));
    1783             :         }
    1784             : 
    1785             :         /*
    1786             :          * If there is a LIMIT/OFFSET clause, add the LIMIT node.
    1787             :          */
    1788      498622 :         if (limit_needed(parse))
    1789             :         {
    1790        5474 :             path = (Path *) create_limit_path(root, final_rel, path,
    1791             :                                               parse->limitOffset,
    1792             :                                               parse->limitCount,
    1793             :                                               parse->limitOption,
    1794             :                                               offset_est, count_est);
    1795             :         }
    1796             : 
    1797             :         /*
    1798             :          * If this is an INSERT/UPDATE/DELETE/MERGE, add the ModifyTable node.
    1799             :          */
    1800      498622 :         if (parse->commandType != CMD_SELECT)
    1801             :         {
    1802             :             Index       rootRelation;
    1803       88406 :             List       *resultRelations = NIL;
    1804       88406 :             List       *updateColnosLists = NIL;
    1805       88406 :             List       *withCheckOptionLists = NIL;
    1806       88406 :             List       *returningLists = NIL;
    1807       88406 :             List       *mergeActionLists = NIL;
    1808             :             List       *rowMarks;
    1809             : 
    1810       88406 :             if (bms_membership(root->all_result_relids) == BMS_MULTIPLE)
    1811             :             {
    1812             :                 /* Inherited UPDATE/DELETE/MERGE */
    1813        2496 :                 RelOptInfo *top_result_rel = find_base_rel(root,
    1814             :                                                            parse->resultRelation);
    1815        2496 :                 int         resultRelation = -1;
    1816             : 
    1817             :                 /* Pass the root result rel forward to the executor. */
    1818        2496 :                 rootRelation = parse->resultRelation;
    1819             : 
    1820             :                 /* Add only leaf children to ModifyTable. */
    1821        7314 :                 while ((resultRelation = bms_next_member(root->leaf_result_relids,
    1822             :                                                          resultRelation)) >= 0)
    1823             :                 {
    1824        4818 :                     RelOptInfo *this_result_rel = find_base_rel(root,
    1825             :                                                                 resultRelation);
    1826             : 
    1827             :                     /*
    1828             :                      * Also exclude any leaf rels that have turned dummy since
    1829             :                      * being added to the list, for example, by being excluded
    1830             :                      * by constraint exclusion.
    1831             :                      */
    1832        4818 :                     if (IS_DUMMY_REL(this_result_rel))
    1833          84 :                         continue;
    1834             : 
    1835             :                     /* Build per-target-rel lists needed by ModifyTable */
    1836        4734 :                     resultRelations = lappend_int(resultRelations,
    1837             :                                                   resultRelation);
    1838        4734 :                     if (parse->commandType == CMD_UPDATE)
    1839             :                     {
    1840        3418 :                         List       *update_colnos = root->update_colnos;
    1841             : 
    1842        3418 :                         if (this_result_rel != top_result_rel)
    1843             :                             update_colnos =
    1844        3418 :                                 adjust_inherited_attnums_multilevel(root,
    1845             :                                                                     update_colnos,
    1846             :                                                                     this_result_rel->relid,
    1847             :                                                                     top_result_rel->relid);
    1848        3418 :                         updateColnosLists = lappend(updateColnosLists,
    1849             :                                                     update_colnos);
    1850             :                     }
    1851        4734 :                     if (parse->withCheckOptions)
    1852             :                     {
    1853         426 :                         List       *withCheckOptions = parse->withCheckOptions;
    1854             : 
    1855         426 :                         if (this_result_rel != top_result_rel)
    1856             :                             withCheckOptions = (List *)
    1857         426 :                                 adjust_appendrel_attrs_multilevel(root,
    1858             :                                                                   (Node *) withCheckOptions,
    1859             :                                                                   this_result_rel,
    1860             :                                                                   top_result_rel);
    1861         426 :                         withCheckOptionLists = lappend(withCheckOptionLists,
    1862             :                                                        withCheckOptions);
    1863             :                     }
    1864        4734 :                     if (parse->returningList)
    1865             :                     {
    1866         534 :                         List       *returningList = parse->returningList;
    1867             : 
    1868         534 :                         if (this_result_rel != top_result_rel)
    1869             :                             returningList = (List *)
    1870         534 :                                 adjust_appendrel_attrs_multilevel(root,
    1871             :                                                                   (Node *) returningList,
    1872             :                                                                   this_result_rel,
    1873             :                                                                   top_result_rel);
    1874         534 :                         returningLists = lappend(returningLists,
    1875             :                                                  returningList);
    1876             :                     }
    1877        4734 :                     if (parse->mergeActionList)
    1878             :                     {
    1879             :                         ListCell   *l;
    1880         348 :                         List       *mergeActionList = NIL;
    1881             : 
    1882             :                         /*
    1883             :                          * Copy MergeActions and translate stuff that
    1884             :                          * references attribute numbers.
    1885             :                          */
    1886         996 :                         foreach(l, parse->mergeActionList)
    1887             :                         {
    1888         648 :                             MergeAction *action = lfirst(l),
    1889         648 :                                        *leaf_action = copyObject(action);
    1890             : 
    1891         648 :                             leaf_action->qual =
    1892         648 :                                 adjust_appendrel_attrs_multilevel(root,
    1893             :                                                                   (Node *) action->qual,
    1894             :                                                                   this_result_rel,
    1895             :                                                                   top_result_rel);
    1896         648 :                             leaf_action->targetList = (List *)
    1897         648 :                                 adjust_appendrel_attrs_multilevel(root,
    1898         648 :                                                                   (Node *) action->targetList,
    1899             :                                                                   this_result_rel,
    1900             :                                                                   top_result_rel);
    1901         648 :                             if (leaf_action->commandType == CMD_UPDATE)
    1902         340 :                                 leaf_action->updateColnos =
    1903         340 :                                     adjust_inherited_attnums_multilevel(root,
    1904             :                                                                         action->updateColnos,
    1905             :                                                                         this_result_rel->relid,
    1906             :                                                                         top_result_rel->relid);
    1907         648 :                             mergeActionList = lappend(mergeActionList,
    1908             :                                                       leaf_action);
    1909             :                         }
    1910             : 
    1911         348 :                         mergeActionLists = lappend(mergeActionLists,
    1912             :                                                    mergeActionList);
    1913             :                     }
    1914             :                 }
    1915             : 
    1916        2496 :                 if (resultRelations == NIL)
    1917             :                 {
    1918             :                     /*
    1919             :                      * We managed to exclude every child rel, so generate a
    1920             :                      * dummy one-relation plan using info for the top target
    1921             :                      * rel (even though that may not be a leaf target).
    1922             :                      * Although it's clear that no data will be updated or
    1923             :                      * deleted, we still need to have a ModifyTable node so
    1924             :                      * that any statement triggers will be executed.  (This
    1925             :                      * could be cleaner if we fixed nodeModifyTable.c to allow
    1926             :                      * zero target relations, but that probably wouldn't be a
    1927             :                      * net win.)
    1928             :                      */
    1929          30 :                     resultRelations = list_make1_int(parse->resultRelation);
    1930          30 :                     if (parse->commandType == CMD_UPDATE)
    1931          30 :                         updateColnosLists = list_make1(root->update_colnos);
    1932          30 :                     if (parse->withCheckOptions)
    1933           0 :                         withCheckOptionLists = list_make1(parse->withCheckOptions);
    1934          30 :                     if (parse->returningList)
    1935          18 :                         returningLists = list_make1(parse->returningList);
    1936          30 :                     if (parse->mergeActionList)
    1937           0 :                         mergeActionLists = list_make1(parse->mergeActionList);
    1938             :                 }
    1939             :             }
    1940             :             else
    1941             :             {
    1942             :                 /* Single-relation INSERT/UPDATE/DELETE/MERGE. */
    1943       85910 :                 rootRelation = 0;   /* there's no separate root rel */
    1944       85910 :                 resultRelations = list_make1_int(parse->resultRelation);
    1945       85910 :                 if (parse->commandType == CMD_UPDATE)
    1946       11526 :                     updateColnosLists = list_make1(root->update_colnos);
    1947       85910 :                 if (parse->withCheckOptions)
    1948         896 :                     withCheckOptionLists = list_make1(parse->withCheckOptions);
    1949       85910 :                 if (parse->returningList)
    1950        2146 :                     returningLists = list_make1(parse->returningList);
    1951       85910 :                 if (parse->mergeActionList)
    1952        1494 :                     mergeActionLists = list_make1(parse->mergeActionList);
    1953             :             }
    1954             : 
    1955             :             /*
    1956             :              * If there was a FOR [KEY] UPDATE/SHARE clause, the LockRows node
    1957             :              * will have dealt with fetching non-locked marked rows, else we
    1958             :              * need to have ModifyTable do that.
    1959             :              */
    1960       88406 :             if (parse->rowMarks)
    1961           0 :                 rowMarks = NIL;
    1962             :             else
    1963       88406 :                 rowMarks = root->rowMarks;
    1964             : 
    1965             :             path = (Path *)
    1966       88406 :                 create_modifytable_path(root, final_rel,
    1967             :                                         path,
    1968             :                                         parse->commandType,
    1969       88406 :                                         parse->canSetTag,
    1970       88406 :                                         parse->resultRelation,
    1971             :                                         rootRelation,
    1972       88406 :                                         root->partColsUpdated,
    1973             :                                         resultRelations,
    1974             :                                         updateColnosLists,
    1975             :                                         withCheckOptionLists,
    1976             :                                         returningLists,
    1977             :                                         rowMarks,
    1978             :                                         parse->onConflict,
    1979             :                                         mergeActionLists,
    1980             :                                         assign_special_exec_param(root));
    1981             :         }
    1982             : 
    1983             :         /* And shove it into final_rel */
    1984      498622 :         add_path(final_rel, path);
    1985             :     }
    1986             : 
    1987             :     /*
    1988             :      * Generate partial paths for final_rel, too, if outer query levels might
    1989             :      * be able to make use of them.
    1990             :      */
    1991      482092 :     if (final_rel->consider_parallel && root->query_level > 1 &&
    1992       18408 :         !limit_needed(parse))
    1993             :     {
    1994             :         Assert(!parse->rowMarks && parse->commandType == CMD_SELECT);
    1995       18354 :         foreach(lc, current_rel->partial_pathlist)
    1996             :         {
    1997         102 :             Path       *partial_path = (Path *) lfirst(lc);
    1998             : 
    1999         102 :             add_partial_path(final_rel, partial_path);
    2000             :         }
    2001             :     }
    2002             : 
    2003      482092 :     extra.limit_needed = limit_needed(parse);
    2004      482092 :     extra.limit_tuples = limit_tuples;
    2005      482092 :     extra.count_est = count_est;
    2006      482092 :     extra.offset_est = offset_est;
    2007             : 
    2008             :     /*
    2009             :      * If there is an FDW that's responsible for all baserels of the query,
    2010             :      * let it consider adding ForeignPaths.
    2011             :      */
    2012      482092 :     if (final_rel->fdwroutine &&
    2013        1214 :         final_rel->fdwroutine->GetForeignUpperPaths)
    2014        1154 :         final_rel->fdwroutine->GetForeignUpperPaths(root, UPPERREL_FINAL,
    2015             :                                                     current_rel, final_rel,
    2016             :                                                     &extra);
    2017             : 
    2018             :     /* Let extensions possibly add some more paths */
    2019      482092 :     if (create_upper_paths_hook)
    2020           0 :         (*create_upper_paths_hook) (root, UPPERREL_FINAL,
    2021             :                                     current_rel, final_rel, &extra);
    2022             : 
    2023             :     /* Note: currently, we leave it to callers to do set_cheapest() */
    2024      482092 : }
    2025             : 
    2026             : /*
    2027             :  * Do preprocessing for groupingSets clause and related data.  This handles the
    2028             :  * preliminary steps of expanding the grouping sets, organizing them into lists
    2029             :  * of rollups, and preparing annotations which will later be filled in with
    2030             :  * size estimates.
    2031             :  */
    2032             : static grouping_sets_data *
    2033         734 : preprocess_grouping_sets(PlannerInfo *root)
    2034             : {
    2035         734 :     Query      *parse = root->parse;
    2036             :     List       *sets;
    2037         734 :     int         maxref = 0;
    2038             :     ListCell   *lc_set;
    2039         734 :     grouping_sets_data *gd = palloc0(sizeof(grouping_sets_data));
    2040             : 
    2041         734 :     parse->groupingSets = expand_grouping_sets(parse->groupingSets, parse->groupDistinct, -1);
    2042             : 
    2043         734 :     gd->any_hashable = false;
    2044         734 :     gd->unhashable_refs = NULL;
    2045         734 :     gd->unsortable_refs = NULL;
    2046         734 :     gd->unsortable_sets = NIL;
    2047             : 
    2048             :     /*
    2049             :      * We don't currently make any attempt to optimize the groupClause when
    2050             :      * there are grouping sets, so just duplicate it in processed_groupClause.
    2051             :      */
    2052         734 :     root->processed_groupClause = parse->groupClause;
    2053             : 
    2054         734 :     if (parse->groupClause)
    2055             :     {
    2056             :         ListCell   *lc;
    2057             : 
    2058        2252 :         foreach(lc, parse->groupClause)
    2059             :         {
    2060        1560 :             SortGroupClause *gc = lfirst_node(SortGroupClause, lc);
    2061        1560 :             Index       ref = gc->tleSortGroupRef;
    2062             : 
    2063        1560 :             if (ref > maxref)
    2064        1524 :                 maxref = ref;
    2065             : 
    2066        1560 :             if (!gc->hashable)
    2067          30 :                 gd->unhashable_refs = bms_add_member(gd->unhashable_refs, ref);
    2068             : 
    2069        1560 :             if (!OidIsValid(gc->sortop))
    2070          42 :                 gd->unsortable_refs = bms_add_member(gd->unsortable_refs, ref);
    2071             :         }
    2072             :     }
    2073             : 
    2074             :     /* Allocate workspace array for remapping */
    2075         734 :     gd->tleref_to_colnum_map = (int *) palloc((maxref + 1) * sizeof(int));
    2076             : 
    2077             :     /*
    2078             :      * If we have any unsortable sets, we must extract them before trying to
    2079             :      * prepare rollups. Unsortable sets don't go through
    2080             :      * reorder_grouping_sets, so we must apply the GroupingSetData annotation
    2081             :      * here.
    2082             :      */
    2083         734 :     if (!bms_is_empty(gd->unsortable_refs))
    2084             :     {
    2085          42 :         List       *sortable_sets = NIL;
    2086             :         ListCell   *lc;
    2087             : 
    2088         126 :         foreach(lc, parse->groupingSets)
    2089             :         {
    2090          90 :             List       *gset = (List *) lfirst(lc);
    2091             : 
    2092          90 :             if (bms_overlap_list(gd->unsortable_refs, gset))
    2093             :             {
    2094          48 :                 GroupingSetData *gs = makeNode(GroupingSetData);
    2095             : 
    2096          48 :                 gs->set = gset;
    2097          48 :                 gd->unsortable_sets = lappend(gd->unsortable_sets, gs);
    2098             : 
    2099             :                 /*
    2100             :                  * We must enforce here that an unsortable set is hashable;
    2101             :                  * later code assumes this.  Parse analysis only checks that
    2102             :                  * every individual column is either hashable or sortable.
    2103             :                  *
    2104             :                  * Note that passing this test doesn't guarantee we can
    2105             :                  * generate a plan; there might be other showstoppers.
    2106             :                  */
    2107          48 :                 if (bms_overlap_list(gd->unhashable_refs, gset))
    2108           6 :                     ereport(ERROR,
    2109             :                             (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
    2110             :                              errmsg("could not implement GROUP BY"),
    2111             :                              errdetail("Some of the datatypes only support hashing, while others only support sorting.")));
    2112             :             }
    2113             :             else
    2114          42 :                 sortable_sets = lappend(sortable_sets, gset);
    2115             :         }
    2116             : 
    2117          36 :         if (sortable_sets)
    2118          30 :             sets = extract_rollup_sets(sortable_sets);
    2119             :         else
    2120           6 :             sets = NIL;
    2121             :     }
    2122             :     else
    2123         692 :         sets = extract_rollup_sets(parse->groupingSets);
    2124             : 
    2125        1938 :     foreach(lc_set, sets)
    2126             :     {
    2127        1210 :         List       *current_sets = (List *) lfirst(lc_set);
    2128        1210 :         RollupData *rollup = makeNode(RollupData);
    2129             :         GroupingSetData *gs;
    2130             : 
    2131             :         /*
    2132             :          * Reorder the current list of grouping sets into correct prefix
    2133             :          * order.  If only one aggregation pass is needed, try to make the
    2134             :          * list match the ORDER BY clause; if more than one pass is needed, we
    2135             :          * don't bother with that.
    2136             :          *
    2137             :          * Note that this reorders the sets from smallest-member-first to
    2138             :          * largest-member-first, and applies the GroupingSetData annotations,
    2139             :          * though the data will be filled in later.
    2140             :          */
    2141        1210 :         current_sets = reorder_grouping_sets(current_sets,
    2142        1210 :                                              (list_length(sets) == 1
    2143             :                                               ? parse->sortClause
    2144             :                                               : NIL));
    2145             : 
    2146             :         /*
    2147             :          * Get the initial (and therefore largest) grouping set.
    2148             :          */
    2149        1210 :         gs = linitial_node(GroupingSetData, current_sets);
    2150             : 
    2151             :         /*
    2152             :          * Order the groupClause appropriately.  If the first grouping set is
    2153             :          * empty, then the groupClause must also be empty; otherwise we have
    2154             :          * to force the groupClause to match that grouping set's order.
    2155             :          *
    2156             :          * (The first grouping set can be empty even though parse->groupClause
    2157             :          * is not empty only if all non-empty grouping sets are unsortable.
    2158             :          * The groupClauses for hashed grouping sets are built later on.)
    2159             :          */
    2160        1210 :         if (gs->set)
    2161        1168 :             rollup->groupClause = groupclause_apply_groupingset(root, gs->set);
    2162             :         else
    2163          42 :             rollup->groupClause = NIL;
    2164             : 
    2165             :         /*
    2166             :          * Is it hashable? We pretend empty sets are hashable even though we
    2167             :          * actually force them not to be hashed later. But don't bother if
    2168             :          * there's nothing but empty sets (since in that case we can't hash
    2169             :          * anything).
    2170             :          */
    2171        1210 :         if (gs->set &&
    2172        1168 :             !bms_overlap_list(gd->unhashable_refs, gs->set))
    2173             :         {
    2174        1144 :             rollup->hashable = true;
    2175        1144 :             gd->any_hashable = true;
    2176             :         }
    2177             : 
    2178             :         /*
    2179             :          * Now that we've pinned down an order for the groupClause for this
    2180             :          * list of grouping sets, we need to remap the entries in the grouping
    2181             :          * sets from sortgrouprefs to plain indices (0-based) into the
    2182             :          * groupClause for this collection of grouping sets. We keep the
    2183             :          * original form for later use, though.
    2184             :          */
    2185        1210 :         rollup->gsets = remap_to_groupclause_idx(rollup->groupClause,
    2186             :                                                  current_sets,
    2187             :                                                  gd->tleref_to_colnum_map);
    2188        1210 :         rollup->gsets_data = current_sets;
    2189             : 
    2190        1210 :         gd->rollups = lappend(gd->rollups, rollup);
    2191             :     }
    2192             : 
    2193         728 :     if (gd->unsortable_sets)
    2194             :     {
    2195             :         /*
    2196             :          * We have not yet pinned down a groupclause for this, but we will
    2197             :          * need index-based lists for estimation purposes. Construct
    2198             :          * hash_sets_idx based on the entire original groupclause for now.
    2199             :          */
    2200          36 :         gd->hash_sets_idx = remap_to_groupclause_idx(parse->groupClause,
    2201             :                                                      gd->unsortable_sets,
    2202             :                                                      gd->tleref_to_colnum_map);
    2203          36 :         gd->any_hashable = true;
    2204             :     }
    2205             : 
    2206         728 :     return gd;
    2207             : }
    2208             : 
    2209             : /*
    2210             :  * Given a groupclause and a list of GroupingSetData, return equivalent sets
    2211             :  * (without annotation) mapped to indexes into the given groupclause.
    2212             :  */
    2213             : static List *
    2214        3588 : remap_to_groupclause_idx(List *groupClause,
    2215             :                          List *gsets,
    2216             :                          int *tleref_to_colnum_map)
    2217             : {
    2218        3588 :     int         ref = 0;
    2219        3588 :     List       *result = NIL;
    2220             :     ListCell   *lc;
    2221             : 
    2222        8920 :     foreach(lc, groupClause)
    2223             :     {
    2224        5332 :         SortGroupClause *gc = lfirst_node(SortGroupClause, lc);
    2225             : 
    2226        5332 :         tleref_to_colnum_map[gc->tleSortGroupRef] = ref++;
    2227             :     }
    2228             : 
    2229        8382 :     foreach(lc, gsets)
    2230             :     {
    2231        4794 :         List       *set = NIL;
    2232             :         ListCell   *lc2;
    2233        4794 :         GroupingSetData *gs = lfirst_node(GroupingSetData, lc);
    2234             : 
    2235       10904 :         foreach(lc2, gs->set)
    2236             :         {
    2237        6110 :             set = lappend_int(set, tleref_to_colnum_map[lfirst_int(lc2)]);
    2238             :         }
    2239             : 
    2240        4794 :         result = lappend(result, set);
    2241             :     }
    2242             : 
    2243        3588 :     return result;
    2244             : }
    2245             : 
    2246             : 
    2247             : /*
    2248             :  * preprocess_rowmarks - set up PlanRowMarks if needed
    2249             :  */
    2250             : static void
    2251      485698 : preprocess_rowmarks(PlannerInfo *root)
    2252             : {
    2253      485698 :     Query      *parse = root->parse;
    2254             :     Bitmapset  *rels;
    2255             :     List       *prowmarks;
    2256             :     ListCell   *l;
    2257             :     int         i;
    2258             : 
    2259      485698 :     if (parse->rowMarks)
    2260             :     {
    2261             :         /*
    2262             :          * We've got trouble if FOR [KEY] UPDATE/SHARE appears inside
    2263             :          * grouping, since grouping renders a reference to individual tuple
    2264             :          * CTIDs invalid.  This is also checked at parse time, but that's
    2265             :          * insufficient because of rule substitution, query pullup, etc.
    2266             :          */
    2267        7488 :         CheckSelectLocking(parse, linitial_node(RowMarkClause,
    2268             :                                                 parse->rowMarks)->strength);
    2269             :     }
    2270             :     else
    2271             :     {
    2272             :         /*
    2273             :          * We only need rowmarks for UPDATE, DELETE, MERGE, or FOR [KEY]
    2274             :          * UPDATE/SHARE.
    2275             :          */
    2276      478210 :         if (parse->commandType != CMD_UPDATE &&
    2277      464866 :             parse->commandType != CMD_DELETE &&
    2278      460656 :             parse->commandType != CMD_MERGE)
    2279      459006 :             return;
    2280             :     }
    2281             : 
    2282             :     /*
    2283             :      * We need to have rowmarks for all base relations except the target. We
    2284             :      * make a bitmapset of all base rels and then remove the items we don't
    2285             :      * need or have FOR [KEY] UPDATE/SHARE marks for.
    2286             :      */
    2287       26692 :     rels = get_relids_in_jointree((Node *) parse->jointree, false, false);
    2288       26692 :     if (parse->resultRelation)
    2289       19204 :         rels = bms_del_member(rels, parse->resultRelation);
    2290             : 
    2291             :     /*
    2292             :      * Convert RowMarkClauses to PlanRowMark representation.
    2293             :      */
    2294       26692 :     prowmarks = NIL;
    2295       34442 :     foreach(l, parse->rowMarks)
    2296             :     {
    2297        7750 :         RowMarkClause *rc = lfirst_node(RowMarkClause, l);
    2298        7750 :         RangeTblEntry *rte = rt_fetch(rc->rti, parse->rtable);
    2299             :         PlanRowMark *newrc;
    2300             : 
    2301             :         /*
    2302             :          * Currently, it is syntactically impossible to have FOR UPDATE et al
    2303             :          * applied to an update/delete target rel.  If that ever becomes
    2304             :          * possible, we should drop the target from the PlanRowMark list.
    2305             :          */
    2306             :         Assert(rc->rti != parse->resultRelation);
    2307             : 
    2308             :         /*
    2309             :          * Ignore RowMarkClauses for subqueries; they aren't real tables and
    2310             :          * can't support true locking.  Subqueries that got flattened into the
    2311             :          * main query should be ignored completely.  Any that didn't will get
    2312             :          * ROW_MARK_COPY items in the next loop.
    2313             :          */
    2314        7750 :         if (rte->rtekind != RTE_RELATION)
    2315         108 :             continue;
    2316             : 
    2317        7642 :         rels = bms_del_member(rels, rc->rti);
    2318             : 
    2319        7642 :         newrc = makeNode(PlanRowMark);
    2320        7642 :         newrc->rti = newrc->prti = rc->rti;
    2321        7642 :         newrc->rowmarkId = ++(root->glob->lastRowMarkId);
    2322        7642 :         newrc->markType = select_rowmark_type(rte, rc->strength);
    2323        7642 :         newrc->allMarkTypes = (1 << newrc->markType);
    2324        7642 :         newrc->strength = rc->strength;
    2325        7642 :         newrc->waitPolicy = rc->waitPolicy;
    2326        7642 :         newrc->isParent = false;
    2327             : 
    2328        7642 :         prowmarks = lappend(prowmarks, newrc);
    2329             :     }
    2330             : 
    2331             :     /*
    2332             :      * Now, add rowmarks for any non-target, non-locked base relations.
    2333             :      */
    2334       26692 :     i = 0;
    2335       63462 :     foreach(l, parse->rtable)
    2336             :     {
    2337       36770 :         RangeTblEntry *rte = lfirst_node(RangeTblEntry, l);
    2338             :         PlanRowMark *newrc;
    2339             : 
    2340       36770 :         i++;
    2341       36770 :         if (!bms_is_member(i, rels))
    2342       33524 :             continue;
    2343             : 
    2344        3246 :         newrc = makeNode(PlanRowMark);
    2345        3246 :         newrc->rti = newrc->prti = i;
    2346        3246 :         newrc->rowmarkId = ++(root->glob->lastRowMarkId);
    2347        3246 :         newrc->markType = select_rowmark_type(rte, LCS_NONE);
    2348        3246 :         newrc->allMarkTypes = (1 << newrc->markType);
    2349        3246 :         newrc->strength = LCS_NONE;
    2350        3246 :         newrc->waitPolicy = LockWaitBlock;   /* doesn't matter */
    2351        3246 :         newrc->isParent = false;
    2352             : 
    2353        3246 :         prowmarks = lappend(prowmarks, newrc);
    2354             :     }
    2355             : 
    2356       26692 :     root->rowMarks = prowmarks;
    2357             : }
    2358             : 
    2359             : /*
    2360             :  * Select RowMarkType to use for a given table
    2361             :  */
    2362             : RowMarkType
    2363       12946 : select_rowmark_type(RangeTblEntry *rte, LockClauseStrength strength)
    2364             : {
    2365       12946 :     if (rte->rtekind != RTE_RELATION)
    2366             :     {
    2367             :         /* If it's not a table at all, use ROW_MARK_COPY */
    2368        1240 :         return ROW_MARK_COPY;
    2369             :     }
    2370       11706 :     else if (rte->relkind == RELKIND_FOREIGN_TABLE)
    2371             :     {
    2372             :         /* Let the FDW select the rowmark type, if it wants to */
    2373         192 :         FdwRoutine *fdwroutine = GetFdwRoutineByRelId(rte->relid);
    2374             : 
    2375         192 :         if (fdwroutine->GetForeignRowMarkType != NULL)
    2376           0 :             return fdwroutine->GetForeignRowMarkType(rte, strength);
    2377             :         /* Otherwise, use ROW_MARK_COPY by default */
    2378         192 :         return ROW_MARK_COPY;
    2379             :     }
    2380             :     else
    2381             :     {
    2382             :         /* Regular table, apply the appropriate lock type */
    2383       11514 :         switch (strength)
    2384             :         {
    2385        2202 :             case LCS_NONE:
    2386             : 
    2387             :                 /*
    2388             :                  * We don't need a tuple lock, only the ability to re-fetch
    2389             :                  * the row.
    2390             :                  */
    2391        2202 :                 return ROW_MARK_REFERENCE;
    2392             :                 break;
    2393        7496 :             case LCS_FORKEYSHARE:
    2394        7496 :                 return ROW_MARK_KEYSHARE;
    2395             :                 break;
    2396         300 :             case LCS_FORSHARE:
    2397         300 :                 return ROW_MARK_SHARE;
    2398             :                 break;
    2399          62 :             case LCS_FORNOKEYUPDATE:
    2400          62 :                 return ROW_MARK_NOKEYEXCLUSIVE;
    2401             :                 break;
    2402        1454 :             case LCS_FORUPDATE:
    2403        1454 :                 return ROW_MARK_EXCLUSIVE;
    2404             :                 break;
    2405             :         }
    2406           0 :         elog(ERROR, "unrecognized LockClauseStrength %d", (int) strength);
    2407             :         return ROW_MARK_EXCLUSIVE;  /* keep compiler quiet */
    2408             :     }
    2409             : }
    2410             : 
    2411             : /*
    2412             :  * preprocess_limit - do pre-estimation for LIMIT and/or OFFSET clauses
    2413             :  *
    2414             :  * We try to estimate the values of the LIMIT/OFFSET clauses, and pass the
    2415             :  * results back in *count_est and *offset_est.  These variables are set to
    2416             :  * 0 if the corresponding clause is not present, and -1 if it's present
    2417             :  * but we couldn't estimate the value for it.  (The "0" convention is OK
    2418             :  * for OFFSET but a little bit bogus for LIMIT: effectively we estimate
    2419             :  * LIMIT 0 as though it were LIMIT 1.  But this is in line with the planner's
    2420             :  * usual practice of never estimating less than one row.)  These values will
    2421             :  * be passed to create_limit_path, which see if you change this code.
    2422             :  *
    2423             :  * The return value is the suitably adjusted tuple_fraction to use for
    2424             :  * planning the query.  This adjustment is not overridable, since it reflects
    2425             :  * plan actions that grouping_planner() will certainly take, not assumptions
    2426             :  * about context.
    2427             :  */
    2428             : static double
    2429        4650 : preprocess_limit(PlannerInfo *root, double tuple_fraction,
    2430             :                  int64 *offset_est, int64 *count_est)
    2431             : {
    2432        4650 :     Query      *parse = root->parse;
    2433             :     Node       *est;
    2434             :     double      limit_fraction;
    2435             : 
    2436             :     /* Should not be called unless LIMIT or OFFSET */
    2437             :     Assert(parse->limitCount || parse->limitOffset);
    2438             : 
    2439             :     /*
    2440             :      * Try to obtain the clause values.  We use estimate_expression_value
    2441             :      * primarily because it can sometimes do something useful with Params.
    2442             :      */
    2443        4650 :     if (parse->limitCount)
    2444             :     {
    2445        4192 :         est = estimate_expression_value(root, parse->limitCount);
    2446        4192 :         if (est && IsA(est, Const))
    2447             :         {
    2448        4186 :             if (((Const *) est)->constisnull)
    2449             :             {
    2450             :                 /* NULL indicates LIMIT ALL, ie, no limit */
    2451           0 :                 *count_est = 0; /* treat as not present */
    2452             :             }
    2453             :             else
    2454             :             {
    2455        4186 :                 *count_est = DatumGetInt64(((Const *) est)->constvalue);
    2456        4186 :                 if (*count_est <= 0)
    2457         150 :                     *count_est = 1; /* force to at least 1 */
    2458             :             }
    2459             :         }
    2460             :         else
    2461           6 :             *count_est = -1;    /* can't estimate */
    2462             :     }
    2463             :     else
    2464         458 :         *count_est = 0;         /* not present */
    2465             : 
    2466        4650 :     if (parse->limitOffset)
    2467             :     {
    2468         818 :         est = estimate_expression_value(root, parse->limitOffset);
    2469         818 :         if (est && IsA(est, Const))
    2470             :         {
    2471         794 :             if (((Const *) est)->constisnull)
    2472             :             {
    2473             :                 /* Treat NULL as no offset; the executor will too */
    2474           0 :                 *offset_est = 0;    /* treat as not present */
    2475             :             }
    2476             :             else
    2477             :             {
    2478         794 :                 *offset_est = DatumGetInt64(((Const *) est)->constvalue);
    2479         794 :                 if (*offset_est < 0)
    2480           0 :                     *offset_est = 0;    /* treat as not present */
    2481             :             }
    2482             :         }
    2483             :         else
    2484          24 :             *offset_est = -1;   /* can't estimate */
    2485             :     }
    2486             :     else
    2487        3832 :         *offset_est = 0;        /* not present */
    2488             : 
    2489        4650 :     if (*count_est != 0)
    2490             :     {
    2491             :         /*
    2492             :          * A LIMIT clause limits the absolute number of tuples returned.
    2493             :          * However, if it's not a constant LIMIT then we have to guess; for
    2494             :          * lack of a better idea, assume 10% of the plan's result is wanted.
    2495             :          */
    2496        4192 :         if (*count_est < 0 || *offset_est < 0)
    2497             :         {
    2498             :             /* LIMIT or OFFSET is an expression ... punt ... */
    2499          24 :             limit_fraction = 0.10;
    2500             :         }
    2501             :         else
    2502             :         {
    2503             :             /* LIMIT (plus OFFSET, if any) is max number of tuples needed */
    2504        4168 :             limit_fraction = (double) *count_est + (double) *offset_est;
    2505             :         }
    2506             : 
    2507             :         /*
    2508             :          * If we have absolute limits from both caller and LIMIT, use the
    2509             :          * smaller value; likewise if they are both fractional.  If one is
    2510             :          * fractional and the other absolute, we can't easily determine which
    2511             :          * is smaller, but we use the heuristic that the absolute will usually
    2512             :          * be smaller.
    2513             :          */
    2514        4192 :         if (tuple_fraction >= 1.0)
    2515             :         {
    2516           6 :             if (limit_fraction >= 1.0)
    2517             :             {
    2518             :                 /* both absolute */
    2519           6 :                 tuple_fraction = Min(tuple_fraction, limit_fraction);
    2520             :             }
    2521             :             else
    2522             :             {
    2523             :                 /* caller absolute, limit fractional; use caller's value */
    2524             :             }
    2525             :         }
    2526        4186 :         else if (tuple_fraction > 0.0)
    2527             :         {
    2528         156 :             if (limit_fraction >= 1.0)
    2529             :             {
    2530             :                 /* caller fractional, limit absolute; use limit */
    2531         156 :                 tuple_fraction = limit_fraction;
    2532             :             }
    2533             :             else
    2534             :             {
    2535             :                 /* both fractional */
    2536           0 :                 tuple_fraction = Min(tuple_fraction, limit_fraction);
    2537             :             }
    2538             :         }
    2539             :         else
    2540             :         {
    2541             :             /* no info from caller, just use limit */
    2542        4030 :             tuple_fraction = limit_fraction;
    2543             :         }
    2544             :     }
    2545         458 :     else if (*offset_est != 0 && tuple_fraction > 0.0)
    2546             :     {
    2547             :         /*
    2548             :          * We have an OFFSET but no LIMIT.  This acts entirely differently
    2549             :          * from the LIMIT case: here, we need to increase rather than decrease
    2550             :          * the caller's tuple_fraction, because the OFFSET acts to cause more
    2551             :          * tuples to be fetched instead of fewer.  This only matters if we got
    2552             :          * a tuple_fraction > 0, however.
    2553             :          *
    2554             :          * As above, use 10% if OFFSET is present but unestimatable.
    2555             :          */
    2556          12 :         if (*offset_est < 0)
    2557           0 :             limit_fraction = 0.10;
    2558             :         else
    2559          12 :             limit_fraction = (double) *offset_est;
    2560             : 
    2561             :         /*
    2562             :          * If we have absolute counts from both caller and OFFSET, add them
    2563             :          * together; likewise if they are both fractional.  If one is
    2564             :          * fractional and the other absolute, we want to take the larger, and
    2565             :          * we heuristically assume that's the fractional one.
    2566             :          */
    2567          12 :         if (tuple_fraction >= 1.0)
    2568             :         {
    2569           0 :             if (limit_fraction >= 1.0)
    2570             :             {
    2571             :                 /* both absolute, so add them together */
    2572           0 :                 tuple_fraction += limit_fraction;
    2573             :             }
    2574             :             else
    2575             :             {
    2576             :                 /* caller absolute, limit fractional; use limit */
    2577           0 :                 tuple_fraction = limit_fraction;
    2578             :             }
    2579             :         }
    2580             :         else
    2581             :         {
    2582          12 :             if (limit_fraction >= 1.0)
    2583             :             {
    2584             :                 /* caller fractional, limit absolute; use caller's value */
    2585             :             }
    2586             :             else
    2587             :             {
    2588             :                 /* both fractional, so add them together */
    2589           0 :                 tuple_fraction += limit_fraction;
    2590           0 :                 if (tuple_fraction >= 1.0)
    2591           0 :                     tuple_fraction = 0.0;   /* assume fetch all */
    2592             :             }
    2593             :         }
    2594             :     }
    2595             : 
    2596        4650 :     return tuple_fraction;
    2597             : }
    2598             : 
    2599             : /*
    2600             :  * limit_needed - do we actually need a Limit plan node?
    2601             :  *
    2602             :  * If we have constant-zero OFFSET and constant-null LIMIT, we can skip adding
    2603             :  * a Limit node.  This is worth checking for because "OFFSET 0" is a common
    2604             :  * locution for an optimization fence.  (Because other places in the planner
    2605             :  * merely check whether parse->limitOffset isn't NULL, it will still work as
    2606             :  * an optimization fence --- we're just suppressing unnecessary run-time
    2607             :  * overhead.)
    2608             :  *
    2609             :  * This might look like it could be merged into preprocess_limit, but there's
    2610             :  * a key distinction: here we need hard constants in OFFSET/LIMIT, whereas
    2611             :  * in preprocess_limit it's good enough to consider estimated values.
    2612             :  */
    2613             : bool
    2614     1005352 : limit_needed(Query *parse)
    2615             : {
    2616             :     Node       *node;
    2617             : 
    2618     1005352 :     node = parse->limitCount;
    2619     1005352 :     if (node)
    2620             :     {
    2621        9942 :         if (IsA(node, Const))
    2622             :         {
    2623             :             /* NULL indicates LIMIT ALL, ie, no limit */
    2624        9750 :             if (!((Const *) node)->constisnull)
    2625        9750 :                 return true;    /* LIMIT with a constant value */
    2626             :         }
    2627             :         else
    2628         192 :             return true;        /* non-constant LIMIT */
    2629             :     }
    2630             : 
    2631      995410 :     node = parse->limitOffset;
    2632      995410 :     if (node)
    2633             :     {
    2634        1364 :         if (IsA(node, Const))
    2635             :         {
    2636             :             /* Treat NULL as no offset; the executor would too */
    2637        1074 :             if (!((Const *) node)->constisnull)
    2638             :             {
    2639        1074 :                 int64       offset = DatumGetInt64(((Const *) node)->constvalue);
    2640             : 
    2641        1074 :                 if (offset != 0)
    2642          84 :                     return true;    /* OFFSET with a nonzero value */
    2643             :             }
    2644             :         }
    2645             :         else
    2646         290 :             return true;        /* non-constant OFFSET */
    2647             :     }
    2648             : 
    2649      995036 :     return false;               /* don't need a Limit plan node */
    2650             : }
    2651             : 
    2652             : 
    2653             : /*
    2654             :  * remove_useless_groupby_columns
    2655             :  *      Remove any columns in the GROUP BY clause that are redundant due to
    2656             :  *      being functionally dependent on other GROUP BY columns.
    2657             :  *
    2658             :  * Since some other DBMSes do not allow references to ungrouped columns, it's
    2659             :  * not unusual to find all columns listed in GROUP BY even though listing the
    2660             :  * primary-key columns would be sufficient.  Deleting such excess columns
    2661             :  * avoids redundant sorting work, so it's worth doing.
    2662             :  *
    2663             :  * Relcache invalidations will ensure that cached plans become invalidated
    2664             :  * when the underlying index of the pkey constraint is dropped.
    2665             :  *
    2666             :  * Currently, we only make use of pkey constraints for this, however, we may
    2667             :  * wish to take this further in the future and also use unique constraints
    2668             :  * which have NOT NULL columns.  In that case, plan invalidation will still
    2669             :  * work since relations will receive a relcache invalidation when a NOT NULL
    2670             :  * constraint is dropped.
    2671             :  */
    2672             : static void
    2673        3366 : remove_useless_groupby_columns(PlannerInfo *root)
    2674             : {
    2675        3366 :     Query      *parse = root->parse;
    2676             :     Bitmapset **groupbyattnos;
    2677             :     Bitmapset **surplusvars;
    2678             :     ListCell   *lc;
    2679             :     int         relid;
    2680             : 
    2681             :     /* No chance to do anything if there are less than two GROUP BY items */
    2682        3366 :     if (list_length(root->processed_groupClause) < 2)
    2683        2090 :         return;
    2684             : 
    2685             :     /* Don't fiddle with the GROUP BY clause if the query has grouping sets */
    2686        1276 :     if (parse->groupingSets)
    2687           0 :         return;
    2688             : 
    2689             :     /*
    2690             :      * Scan the GROUP BY clause to find GROUP BY items that are simple Vars.
    2691             :      * Fill groupbyattnos[k] with a bitmapset of the column attnos of RTE k
    2692             :      * that are GROUP BY items.
    2693             :      */
    2694        1276 :     groupbyattnos = (Bitmapset **) palloc0(sizeof(Bitmapset *) *
    2695        1276 :                                            (list_length(parse->rtable) + 1));
    2696        4562 :     foreach(lc, root->processed_groupClause)
    2697             :     {
    2698        3286 :         SortGroupClause *sgc = lfirst_node(SortGroupClause, lc);
    2699        3286 :         TargetEntry *tle = get_sortgroupclause_tle(sgc, parse->targetList);
    2700        3286 :         Var        *var = (Var *) tle->expr;
    2701             : 
    2702             :         /*
    2703             :          * Ignore non-Vars and Vars from other query levels.
    2704             :          *
    2705             :          * XXX in principle, stable expressions containing Vars could also be
    2706             :          * removed, if all the Vars are functionally dependent on other GROUP
    2707             :          * BY items.  But it's not clear that such cases occur often enough to
    2708             :          * be worth troubling over.
    2709             :          */
    2710        3286 :         if (!IsA(var, Var) ||
    2711        2414 :             var->varlevelsup > 0)
    2712         872 :             continue;
    2713             : 
    2714             :         /* OK, remember we have this Var */
    2715        2414 :         relid = var->varno;
    2716             :         Assert(relid <= list_length(parse->rtable));
    2717        2414 :         groupbyattnos[relid] = bms_add_member(groupbyattnos[relid],
    2718        2414 :                                               var->varattno - FirstLowInvalidHeapAttributeNumber);
    2719             :     }
    2720             : 
    2721             :     /*
    2722             :      * Consider each relation and see if it is possible to remove some of its
    2723             :      * Vars from GROUP BY.  For simplicity and speed, we do the actual removal
    2724             :      * in a separate pass.  Here, we just fill surplusvars[k] with a bitmapset
    2725             :      * of the column attnos of RTE k that are removable GROUP BY items.
    2726             :      */
    2727        1276 :     surplusvars = NULL;         /* don't allocate array unless required */
    2728        1276 :     relid = 0;
    2729        3502 :     foreach(lc, parse->rtable)
    2730             :     {
    2731        2226 :         RangeTblEntry *rte = lfirst_node(RangeTblEntry, lc);
    2732             :         Bitmapset  *relattnos;
    2733             :         Bitmapset  *pkattnos;
    2734             :         Oid         constraintOid;
    2735             : 
    2736        2226 :         relid++;
    2737             : 
    2738             :         /* Only plain relations could have primary-key constraints */
    2739        2226 :         if (rte->rtekind != RTE_RELATION)
    2740        2044 :             continue;
    2741             : 
    2742             :         /*
    2743             :          * We must skip inheritance parent tables as some of the child rels
    2744             :          * may cause duplicate rows.  This cannot happen with partitioned
    2745             :          * tables, however.
    2746             :          */
    2747        1652 :         if (rte->inh && rte->relkind != RELKIND_PARTITIONED_TABLE)
    2748          18 :             continue;
    2749             : 
    2750             :         /* Nothing to do unless this rel has multiple Vars in GROUP BY */
    2751        1634 :         relattnos = groupbyattnos[relid];
    2752        1634 :         if (bms_membership(relattnos) != BMS_MULTIPLE)
    2753         874 :             continue;
    2754             : 
    2755             :         /*
    2756             :          * Can't remove any columns for this rel if there is no suitable
    2757             :          * (i.e., nondeferrable) primary key constraint.
    2758             :          */
    2759         760 :         pkattnos = get_primary_key_attnos(rte->relid, false, &constraintOid);
    2760         760 :         if (pkattnos == NULL)
    2761         578 :             continue;
    2762             : 
    2763             :         /*
    2764             :          * If the primary key is a proper subset of relattnos then we have
    2765             :          * some items in the GROUP BY that can be removed.
    2766             :          */
    2767         182 :         if (bms_subset_compare(pkattnos, relattnos) == BMS_SUBSET1)
    2768             :         {
    2769             :             /*
    2770             :              * To easily remember whether we've found anything to do, we don't
    2771             :              * allocate the surplusvars[] array until we find something.
    2772             :              */
    2773         164 :             if (surplusvars == NULL)
    2774         158 :                 surplusvars = (Bitmapset **) palloc0(sizeof(Bitmapset *) *
    2775         158 :                                                      (list_length(parse->rtable) + 1));
    2776             : 
    2777             :             /* Remember the attnos of the removable columns */
    2778         164 :             surplusvars[relid] = bms_difference(relattnos, pkattnos);
    2779             :         }
    2780             :     }
    2781             : 
    2782             :     /*
    2783             :      * If we found any surplus Vars, build a new GROUP BY clause without them.
    2784             :      * (Note: this may leave some TLEs with unreferenced ressortgroupref
    2785             :      * markings, but that's harmless.)
    2786             :      */
    2787        1276 :     if (surplusvars != NULL)
    2788             :     {
    2789         158 :         List       *new_groupby = NIL;
    2790             : 
    2791         678 :         foreach(lc, root->processed_groupClause)
    2792             :         {
    2793         520 :             SortGroupClause *sgc = lfirst_node(SortGroupClause, lc);
    2794         520 :             TargetEntry *tle = get_sortgroupclause_tle(sgc, parse->targetList);
    2795         520 :             Var        *var = (Var *) tle->expr;
    2796             : 
    2797             :             /*
    2798             :              * New list must include non-Vars, outer Vars, and anything not
    2799             :              * marked as surplus.
    2800             :              */
    2801         520 :             if (!IsA(var, Var) ||
    2802         520 :                 var->varlevelsup > 0 ||
    2803         520 :                 !bms_is_member(var->varattno - FirstLowInvalidHeapAttributeNumber,
    2804         520 :                                surplusvars[var->varno]))
    2805         326 :                 new_groupby = lappend(new_groupby, sgc);
    2806             :         }
    2807             : 
    2808         158 :         root->processed_groupClause = new_groupby;
    2809             :     }
    2810             : }
    2811             : 
    2812             : /*
    2813             :  * groupclause_apply_groupingset
    2814             :  *      Apply the order of GROUP BY clauses defined by grouping sets.  Items
    2815             :  *      not in the grouping set are skipped.
    2816             :  */
    2817             : static List *
    2818        3510 : groupclause_apply_groupingset(PlannerInfo *root, List *gset)
    2819             : {
    2820        3510 :     Query      *parse = root->parse;
    2821        3510 :     List       *new_groupclause = NIL;
    2822             :     ListCell   *sl;
    2823             : 
    2824        8764 :     foreach(sl, gset)
    2825             :     {
    2826        5254 :         Index       ref = lfirst_int(sl);
    2827        5254 :         SortGroupClause *cl = get_sortgroupref_clause(ref, parse->groupClause);
    2828             : 
    2829        5254 :         new_groupclause = lappend(new_groupclause, cl);
    2830             :     }
    2831        3510 :     return new_groupclause;
    2832             : }
    2833             : 
    2834             : /*
    2835             :  * Extract lists of grouping sets that can be implemented using a single
    2836             :  * rollup-type aggregate pass each. Returns a list of lists of grouping sets.
    2837             :  *
    2838             :  * Input must be sorted with smallest sets first. Result has each sublist
    2839             :  * sorted with smallest sets first.
    2840             :  *
    2841             :  * We want to produce the absolute minimum possible number of lists here to
    2842             :  * avoid excess sorts. Fortunately, there is an algorithm for this; the problem
    2843             :  * of finding the minimal partition of a partially-ordered set into chains
    2844             :  * (which is what we need, taking the list of grouping sets as a poset ordered
    2845             :  * by set inclusion) can be mapped to the problem of finding the maximum
    2846             :  * cardinality matching on a bipartite graph, which is solvable in polynomial
    2847             :  * time with a worst case of no worse than O(n^2.5) and usually much
    2848             :  * better. Since our N is at most 4096, we don't need to consider fallbacks to
    2849             :  * heuristic or approximate methods.  (Planning time for a 12-d cube is under
    2850             :  * half a second on my modest system even with optimization off and assertions
    2851             :  * on.)
    2852             :  */
    2853             : static List *
    2854         722 : extract_rollup_sets(List *groupingSets)
    2855             : {
    2856         722 :     int         num_sets_raw = list_length(groupingSets);
    2857         722 :     int         num_empty = 0;
    2858         722 :     int         num_sets = 0;   /* distinct sets */
    2859         722 :     int         num_chains = 0;
    2860         722 :     List       *result = NIL;
    2861             :     List      **results;
    2862             :     List      **orig_sets;
    2863             :     Bitmapset **set_masks;
    2864             :     int        *chains;
    2865             :     short     **adjacency;
    2866             :     short      *adjacency_buf;
    2867             :     BipartiteMatchState *state;
    2868             :     int         i;
    2869             :     int         j;
    2870             :     int         j_size;
    2871         722 :     ListCell   *lc1 = list_head(groupingSets);
    2872             :     ListCell   *lc;
    2873             : 
    2874             :     /*
    2875             :      * Start by stripping out empty sets.  The algorithm doesn't require this,
    2876             :      * but the planner currently needs all empty sets to be returned in the
    2877             :      * first list, so we strip them here and add them back after.
    2878             :      */
    2879        1296 :     while (lc1 && lfirst(lc1) == NIL)
    2880             :     {
    2881         574 :         ++num_empty;
    2882         574 :         lc1 = lnext(groupingSets, lc1);
    2883             :     }
    2884             : 
    2885             :     /* bail out now if it turns out that all we had were empty sets. */
    2886         722 :     if (!lc1)
    2887          42 :         return list_make1(groupingSets);
    2888             : 
    2889             :     /*----------
    2890             :      * We don't strictly need to remove duplicate sets here, but if we don't,
    2891             :      * they tend to become scattered through the result, which is a bit
    2892             :      * confusing (and irritating if we ever decide to optimize them out).
    2893             :      * So we remove them here and add them back after.
    2894             :      *
    2895             :      * For each non-duplicate set, we fill in the following:
    2896             :      *
    2897             :      * orig_sets[i] = list of the original set lists
    2898             :      * set_masks[i] = bitmapset for testing inclusion
    2899             :      * adjacency[i] = array [n, v1, v2, ... vn] of adjacency indices
    2900             :      *
    2901             :      * chains[i] will be the result group this set is assigned to.
    2902             :      *
    2903             :      * We index all of these from 1 rather than 0 because it is convenient
    2904             :      * to leave 0 free for the NIL node in the graph algorithm.
    2905             :      *----------
    2906             :      */
    2907         680 :     orig_sets = palloc0((num_sets_raw + 1) * sizeof(List *));
    2908         680 :     set_masks = palloc0((num_sets_raw + 1) * sizeof(Bitmapset *));
    2909         680 :     adjacency = palloc0((num_sets_raw + 1) * sizeof(short *));
    2910         680 :     adjacency_buf = palloc((num_sets_raw + 1) * sizeof(short));
    2911             : 
    2912         680 :     j_size = 0;
    2913         680 :     j = 0;
    2914         680 :     i = 1;
    2915             : 
    2916        2516 :     for_each_cell(lc, groupingSets, lc1)
    2917             :     {
    2918        1836 :         List       *candidate = (List *) lfirst(lc);
    2919        1836 :         Bitmapset  *candidate_set = NULL;
    2920             :         ListCell   *lc2;
    2921        1836 :         int         dup_of = 0;
    2922             : 
    2923        4506 :         foreach(lc2, candidate)
    2924             :         {
    2925        2670 :             candidate_set = bms_add_member(candidate_set, lfirst_int(lc2));
    2926             :         }
    2927             : 
    2928             :         /* we can only be a dup if we're the same length as a previous set */
    2929        1836 :         if (j_size == list_length(candidate))
    2930             :         {
    2931             :             int         k;
    2932             : 
    2933        1664 :             for (k = j; k < i; ++k)
    2934             :             {
    2935        1080 :                 if (bms_equal(set_masks[k], candidate_set))
    2936             :                 {
    2937         158 :                     dup_of = k;
    2938         158 :                     break;
    2939             :                 }
    2940             :             }
    2941             :         }
    2942        1094 :         else if (j_size < list_length(candidate))
    2943             :         {
    2944        1094 :             j_size = list_length(candidate);
    2945        1094 :             j = i;
    2946             :         }
    2947             : 
    2948        1836 :         if (dup_of > 0)
    2949             :         {
    2950         158 :             orig_sets[dup_of] = lappend(orig_sets[dup_of], candidate);
    2951         158 :             bms_free(candidate_set);
    2952             :         }
    2953             :         else
    2954             :         {
    2955             :             int         k;
    2956        1678 :             int         n_adj = 0;
    2957             : 
    2958        1678 :             orig_sets[i] = list_make1(candidate);
    2959        1678 :             set_masks[i] = candidate_set;
    2960             : 
    2961             :             /* fill in adjacency list; no need to compare equal-size sets */
    2962             : 
    2963        2890 :             for (k = j - 1; k > 0; --k)
    2964             :             {
    2965        1212 :                 if (bms_is_subset(set_masks[k], candidate_set))
    2966        1050 :                     adjacency_buf[++n_adj] = k;
    2967             :             }
    2968             : 
    2969        1678 :             if (n_adj > 0)
    2970             :             {
    2971         538 :                 adjacency_buf[0] = n_adj;
    2972         538 :                 adjacency[i] = palloc((n_adj + 1) * sizeof(short));
    2973         538 :                 memcpy(adjacency[i], adjacency_buf, (n_adj + 1) * sizeof(short));
    2974             :             }
    2975             :             else
    2976        1140 :                 adjacency[i] = NULL;
    2977             : 
    2978        1678 :             ++i;
    2979             :         }
    2980             :     }
    2981             : 
    2982         680 :     num_sets = i - 1;
    2983             : 
    2984             :     /*
    2985             :      * Apply the graph matching algorithm to do the work.
    2986             :      */
    2987         680 :     state = BipartiteMatch(num_sets, num_sets, adjacency);
    2988             : 
    2989             :     /*
    2990             :      * Now, the state->pair* fields have the info we need to assign sets to
    2991             :      * chains. Two sets (u,v) belong to the same chain if pair_uv[u] = v or
    2992             :      * pair_vu[v] = u (both will be true, but we check both so that we can do
    2993             :      * it in one pass)
    2994             :      */
    2995         680 :     chains = palloc0((num_sets + 1) * sizeof(int));
    2996             : 
    2997        2358 :     for (i = 1; i <= num_sets; ++i)
    2998             :     {
    2999        1678 :         int         u = state->pair_vu[i];
    3000        1678 :         int         v = state->pair_uv[i];
    3001             : 
    3002        1678 :         if (u > 0 && u < i)
    3003           0 :             chains[i] = chains[u];
    3004        1678 :         else if (v > 0 && v < i)
    3005         510 :             chains[i] = chains[v];
    3006             :         else
    3007        1168 :             chains[i] = ++num_chains;
    3008             :     }
    3009             : 
    3010             :     /* build result lists. */
    3011         680 :     results = palloc0((num_chains + 1) * sizeof(List *));
    3012             : 
    3013        2358 :     for (i = 1; i <= num_sets; ++i)
    3014             :     {
    3015        1678 :         int         c = chains[i];
    3016             : 
    3017             :         Assert(c > 0);
    3018             : 
    3019        1678 :         results[c] = list_concat(results[c], orig_sets[i]);
    3020             :     }
    3021             : 
    3022             :     /* push any empty sets back on the first list. */
    3023        1164 :     while (num_empty-- > 0)
    3024         484 :         results[1] = lcons(NIL, results[1]);
    3025             : 
    3026             :     /* make result list */
    3027        1848 :     for (i = 1; i <= num_chains; ++i)
    3028        1168 :         result = lappend(result, results[i]);
    3029             : 
    3030             :     /*
    3031             :      * Free all the things.
    3032             :      *
    3033             :      * (This is over-fussy for small sets but for large sets we could have
    3034             :      * tied up a nontrivial amount of memory.)
    3035             :      */
    3036         680 :     BipartiteMatchFree(state);
    3037         680 :     pfree(results);
    3038         680 :     pfree(chains);
    3039        2358 :     for (i = 1; i <= num_sets; ++i)
    3040        1678 :         if (adjacency[i])
    3041         538 :             pfree(adjacency[i]);
    3042         680 :     pfree(adjacency);
    3043         680 :     pfree(adjacency_buf);
    3044         680 :     pfree(orig_sets);
    3045        2358 :     for (i = 1; i <= num_sets; ++i)
    3046        1678 :         bms_free(set_masks[i]);
    3047         680 :     pfree(set_masks);
    3048             : 
    3049         680 :     return result;
    3050             : }
    3051             : 
    3052             : /*
    3053             :  * Reorder the elements of a list of grouping sets such that they have correct
    3054             :  * prefix relationships. Also inserts the GroupingSetData annotations.
    3055             :  *
    3056             :  * The input must be ordered with smallest sets first; the result is returned
    3057             :  * with largest sets first.  Note that the result shares no list substructure
    3058             :  * with the input, so it's safe for the caller to modify it later.
    3059             :  *
    3060             :  * If we're passed in a sortclause, we follow its order of columns to the
    3061             :  * extent possible, to minimize the chance that we add unnecessary sorts.
    3062             :  * (We're trying here to ensure that GROUPING SETS ((a,b,c),(c)) ORDER BY c,b,a
    3063             :  * gets implemented in one pass.)
    3064             :  */
    3065             : static List *
    3066        1210 : reorder_grouping_sets(List *groupingSets, List *sortclause)
    3067             : {
    3068             :     ListCell   *lc;
    3069        1210 :     List       *previous = NIL;
    3070        1210 :     List       *result = NIL;
    3071             : 
    3072        3620 :     foreach(lc, groupingSets)
    3073             :     {
    3074        2410 :         List       *candidate = (List *) lfirst(lc);
    3075        2410 :         List       *new_elems = list_difference_int(candidate, previous);
    3076        2410 :         GroupingSetData *gs = makeNode(GroupingSetData);
    3077             : 
    3078        2490 :         while (list_length(sortclause) > list_length(previous) &&
    3079             :                new_elems != NIL)
    3080             :         {
    3081         188 :             SortGroupClause *sc = list_nth(sortclause, list_length(previous));
    3082         188 :             int         ref = sc->tleSortGroupRef;
    3083             : 
    3084         188 :             if (list_member_int(new_elems, ref))
    3085             :             {
    3086          80 :                 previous = lappend_int(previous, ref);
    3087          80 :                 new_elems = list_delete_int(new_elems, ref);
    3088             :             }
    3089             :             else
    3090             :             {
    3091             :                 /* diverged from the sortclause; give up on it */
    3092         108 :                 sortclause = NIL;
    3093         108 :                 break;
    3094             :             }
    3095             :         }
    3096             : 
    3097        2410 :         previous = list_concat(previous, new_elems);
    3098             : 
    3099        2410 :         gs->set = list_copy(previous);
    3100        2410 :         result = lcons(gs, result);
    3101             :     }
    3102             : 
    3103        1210 :     list_free(previous);
    3104             : 
    3105        1210 :     return result;
    3106             : }
    3107             : 
    3108             : /*
    3109             :  * has_volatile_pathkey
    3110             :  *      Returns true if any PathKey in 'keys' has an EquivalenceClass
    3111             :  *      containing a volatile function.  Otherwise returns false.
    3112             :  */
    3113             : static bool
    3114        2208 : has_volatile_pathkey(List *keys)
    3115             : {
    3116             :     ListCell   *lc;
    3117             : 
    3118        4576 :     foreach(lc, keys)
    3119             :     {
    3120        2382 :         PathKey    *pathkey = lfirst_node(PathKey, lc);
    3121             : 
    3122        2382 :         if (pathkey->pk_eclass->ec_has_volatile)
    3123          14 :             return true;
    3124             :     }
    3125             : 
    3126        2194 :     return false;
    3127             : }
    3128             : 
    3129             : /*
    3130             :  * adjust_group_pathkeys_for_groupagg
    3131             :  *      Add pathkeys to root->group_pathkeys to reflect the best set of
    3132             :  *      pre-ordered input for ordered aggregates.
    3133             :  *
    3134             :  * We define "best" as the pathkeys that suit the largest number of
    3135             :  * aggregate functions.  We find these by looking at the first ORDER BY /
    3136             :  * DISTINCT aggregate and take the pathkeys for that before searching for
    3137             :  * other aggregates that require the same or a more strict variation of the
    3138             :  * same pathkeys.  We then repeat that process for any remaining aggregates
    3139             :  * with different pathkeys and if we find another set of pathkeys that suits a
    3140             :  * larger number of aggregates then we select those pathkeys instead.
    3141             :  *
    3142             :  * When the best pathkeys are found we also mark each Aggref that can use
    3143             :  * those pathkeys as aggpresorted = true.
    3144             :  *
    3145             :  * Note: When an aggregate function's ORDER BY / DISTINCT clause contains any
    3146             :  * volatile functions, we never make use of these pathkeys.  We want to ensure
    3147             :  * that sorts using volatile functions are done independently in each Aggref
    3148             :  * rather than once at the query level.  If we were to allow this then Aggrefs
    3149             :  * with compatible sort orders would all transition their rows in the same
    3150             :  * order if those pathkeys were deemed to be the best pathkeys to sort on.
    3151             :  * Whereas, if some other set of Aggref's pathkeys happened to be deemed
    3152             :  * better pathkeys to sort on, then the volatile function Aggrefs would be
    3153             :  * left to perform their sorts individually.  To avoid this inconsistent
    3154             :  * behavior which could make Aggref results depend on what other Aggrefs the
    3155             :  * query contains, we always force Aggrefs with volatile functions to perform
    3156             :  * their own sorts.
    3157             :  */
    3158             : static void
    3159        1788 : adjust_group_pathkeys_for_groupagg(PlannerInfo *root)
    3160             : {
    3161        1788 :     List       *grouppathkeys = root->group_pathkeys;
    3162             :     List       *bestpathkeys;
    3163             :     Bitmapset  *bestaggs;
    3164             :     Bitmapset  *unprocessed_aggs;
    3165             :     ListCell   *lc;
    3166             :     int         i;
    3167             : 
    3168             :     /* Shouldn't be here if there are grouping sets */
    3169             :     Assert(root->parse->groupingSets == NIL);
    3170             :     /* Shouldn't be here unless there are some ordered aggregates */
    3171             :     Assert(root->numOrderedAggs > 0);
    3172             : 
    3173             :     /* Do nothing if disabled */
    3174        1788 :     if (!enable_presorted_aggregate)
    3175           6 :         return;
    3176             : 
    3177             :     /*
    3178             :      * Make a first pass over all AggInfos to collect a Bitmapset containing
    3179             :      * the indexes of all AggInfos to be processed below.
    3180             :      */
    3181        1782 :     unprocessed_aggs = NULL;
    3182        4248 :     foreach(lc, root->agginfos)
    3183             :     {
    3184        2466 :         AggInfo    *agginfo = lfirst_node(AggInfo, lc);
    3185        2466 :         Aggref     *aggref = linitial_node(Aggref, agginfo->aggrefs);
    3186             : 
    3187        2466 :         if (AGGKIND_IS_ORDERED_SET(aggref->aggkind))
    3188         264 :             continue;
    3189             : 
    3190             :         /* only add aggregates with a DISTINCT or ORDER BY */
    3191        2202 :         if (aggref->aggdistinct != NIL || aggref->aggorder != NIL)
    3192        1902 :             unprocessed_aggs = bms_add_member(unprocessed_aggs,
    3193             :                                               foreach_current_index(lc));
    3194             :     }
    3195             : 
    3196             :     /*
    3197             :      * Now process all the unprocessed_aggs to find the best set of pathkeys
    3198             :      * for the given set of aggregates.
    3199             :      *
    3200             :      * On the first outer loop here 'bestaggs' will be empty.   We'll populate
    3201             :      * this during the first loop using the pathkeys for the very first
    3202             :      * AggInfo then taking any stronger pathkeys from any other AggInfos with
    3203             :      * a more strict set of compatible pathkeys.  Once the outer loop is
    3204             :      * complete, we mark off all the aggregates with compatible pathkeys then
    3205             :      * remove those from the unprocessed_aggs and repeat the process to try to
    3206             :      * find another set of pathkeys that are suitable for a larger number of
    3207             :      * aggregates.  The outer loop will stop when there are not enough
    3208             :      * unprocessed aggregates for it to be possible to find a set of pathkeys
    3209             :      * to suit a larger number of aggregates.
    3210             :      */
    3211        1782 :     bestpathkeys = NIL;
    3212        1782 :     bestaggs = NULL;
    3213        3516 :     while (bms_num_members(unprocessed_aggs) > bms_num_members(bestaggs))
    3214             :     {
    3215        1734 :         Bitmapset  *aggindexes = NULL;
    3216        1734 :         List       *currpathkeys = NIL;
    3217             : 
    3218        1734 :         i = -1;
    3219        5676 :         while ((i = bms_next_member(unprocessed_aggs, i)) >= 0)
    3220             :         {
    3221        2208 :             AggInfo    *agginfo = list_nth_node(AggInfo, root->agginfos, i);
    3222        2208 :             Aggref     *aggref = linitial_node(Aggref, agginfo->aggrefs);
    3223             :             List       *sortlist;
    3224             :             List       *pathkeys;
    3225             : 
    3226        2208 :             if (aggref->aggdistinct != NIL)
    3227         702 :                 sortlist = aggref->aggdistinct;
    3228             :             else
    3229        1506 :                 sortlist = aggref->aggorder;
    3230             : 
    3231        2208 :             pathkeys = make_pathkeys_for_sortclauses(root, sortlist,
    3232             :                                                      aggref->args);
    3233             : 
    3234             :             /*
    3235             :              * Ignore Aggrefs which have volatile functions in their ORDER BY
    3236             :              * or DISTINCT clause.
    3237             :              */
    3238        2208 :             if (has_volatile_pathkey(pathkeys))
    3239             :             {
    3240          14 :                 unprocessed_aggs = bms_del_member(unprocessed_aggs, i);
    3241          14 :                 continue;
    3242             :             }
    3243             : 
    3244             :             /*
    3245             :              * When not set yet, take the pathkeys from the first unprocessed
    3246             :              * aggregate.
    3247             :              */
    3248        2194 :             if (currpathkeys == NIL)
    3249             :             {
    3250        1732 :                 currpathkeys = pathkeys;
    3251             : 
    3252             :                 /* include the GROUP BY pathkeys, if they exist */
    3253        1732 :                 if (grouppathkeys != NIL)
    3254         270 :                     currpathkeys = append_pathkeys(list_copy(grouppathkeys),
    3255             :                                                    currpathkeys);
    3256             : 
    3257             :                 /* record that we found pathkeys for this aggregate */
    3258        1732 :                 aggindexes = bms_add_member(aggindexes, i);
    3259             :             }
    3260             :             else
    3261             :             {
    3262             :                 /* now look for a stronger set of matching pathkeys */
    3263             : 
    3264             :                 /* include the GROUP BY pathkeys, if they exist */
    3265         462 :                 if (grouppathkeys != NIL)
    3266         288 :                     pathkeys = append_pathkeys(list_copy(grouppathkeys),
    3267             :                                                pathkeys);
    3268             : 
    3269             :                 /* are 'pathkeys' compatible or better than 'currpathkeys'? */
    3270         462 :                 switch (compare_pathkeys(currpathkeys, pathkeys))
    3271             :                 {
    3272          12 :                     case PATHKEYS_BETTER2:
    3273             :                         /* 'pathkeys' are stronger, use these ones instead */
    3274          12 :                         currpathkeys = pathkeys;
    3275             :                         /* FALLTHROUGH */
    3276             : 
    3277          72 :                     case PATHKEYS_BETTER1:
    3278             :                         /* 'pathkeys' are less strict */
    3279             :                         /* FALLTHROUGH */
    3280             : 
    3281             :                     case PATHKEYS_EQUAL:
    3282             :                         /* mark this aggregate as covered by 'currpathkeys' */
    3283          72 :                         aggindexes = bms_add_member(aggindexes, i);
    3284          72 :                         break;
    3285             : 
    3286         390 :                     case PATHKEYS_DIFFERENT:
    3287         390 :                         break;
    3288             :                 }
    3289        3942 :             }
    3290             :         }
    3291             : 
    3292             :         /* remove the aggregates that we've just processed */
    3293        1734 :         unprocessed_aggs = bms_del_members(unprocessed_aggs, aggindexes);
    3294             : 
    3295             :         /*
    3296             :          * If this pass included more aggregates than the previous best then
    3297             :          * use these ones as the best set.
    3298             :          */
    3299        1734 :         if (bms_num_members(aggindexes) > bms_num_members(bestaggs))
    3300             :         {
    3301        1630 :             bestaggs = aggindexes;
    3302        1630 :             bestpathkeys = currpathkeys;
    3303             :         }
    3304             :     }
    3305             : 
    3306             :     /*
    3307             :      * If we found any ordered aggregates, update root->group_pathkeys to add
    3308             :      * the best set of aggregate pathkeys.  Note that bestpathkeys includes
    3309             :      * the original GROUP BY pathkeys already.
    3310             :      */
    3311        1782 :     if (bestpathkeys != NIL)
    3312        1582 :         root->group_pathkeys = bestpathkeys;
    3313             : 
    3314             :     /*
    3315             :      * Now that we've found the best set of aggregates we can set the
    3316             :      * presorted flag to indicate to the executor that it needn't bother
    3317             :      * performing a sort for these Aggrefs.  We're able to do this now as
    3318             :      * there's no chance of a Hash Aggregate plan as create_grouping_paths
    3319             :      * will not mark the GROUP BY as GROUPING_CAN_USE_HASH due to the presence
    3320             :      * of ordered aggregates.
    3321             :      */
    3322        1782 :     i = -1;
    3323        3454 :     while ((i = bms_next_member(bestaggs, i)) >= 0)
    3324             :     {
    3325        1672 :         AggInfo    *agginfo = list_nth_node(AggInfo, root->agginfos, i);
    3326             : 
    3327        3362 :         foreach(lc, agginfo->aggrefs)
    3328             :         {
    3329        1690 :             Aggref     *aggref = lfirst_node(Aggref, lc);
    3330             : 
    3331        1690 :             aggref->aggpresorted = true;
    3332             :         }
    3333             :     }
    3334             : }
    3335             : 
    3336             : /*
    3337             :  * Compute query_pathkeys and other pathkeys during plan generation
    3338             :  */
    3339             : static void
    3340      476978 : standard_qp_callback(PlannerInfo *root, void *extra)
    3341             : {
    3342      476978 :     Query      *parse = root->parse;
    3343      476978 :     standard_qp_extra *qp_extra = (standard_qp_extra *) extra;
    3344      476978 :     List       *tlist = root->processed_tlist;
    3345      476978 :     List       *activeWindows = qp_extra->activeWindows;
    3346             : 
    3347             :     /*
    3348             :      * Calculate pathkeys that represent grouping/ordering and/or ordered
    3349             :      * aggregate requirements.
    3350             :      */
    3351      476978 :     if (qp_extra->gset_data)
    3352             :     {
    3353             :         /*
    3354             :          * With grouping sets, just use the first RollupData's groupClause. We
    3355             :          * don't make any effort to optimize grouping clauses when there are
    3356             :          * grouping sets, nor can we combine aggregate ordering keys with
    3357             :          * grouping.
    3358             :          */
    3359         728 :         List       *rollups = qp_extra->gset_data->rollups;
    3360         728 :         List       *groupClause = (rollups ? linitial_node(RollupData, rollups)->groupClause : NIL);
    3361             : 
    3362         728 :         if (grouping_is_sortable(groupClause))
    3363             :         {
    3364         728 :             root->group_pathkeys = make_pathkeys_for_sortclauses(root,
    3365             :                                                                  groupClause,
    3366             :                                                                  tlist);
    3367         728 :             root->num_groupby_pathkeys = list_length(root->group_pathkeys);
    3368             :         }
    3369             :         else
    3370             :         {
    3371           0 :             root->group_pathkeys = NIL;
    3372           0 :             root->num_groupby_pathkeys = 0;
    3373             :         }
    3374             :     }
    3375      476250 :     else if (parse->groupClause || root->numOrderedAggs > 0)
    3376        4916 :     {
    3377             :         /*
    3378             :          * With a plain GROUP BY list, we can remove any grouping items that
    3379             :          * are proven redundant by EquivalenceClass processing.  For example,
    3380             :          * we can remove y given "WHERE x = y GROUP BY x, y".  These aren't
    3381             :          * especially common cases, but they're nearly free to detect.  Note
    3382             :          * that we remove redundant items from processed_groupClause but not
    3383             :          * the original parse->groupClause.
    3384             :          */
    3385             :         bool        sortable;
    3386             : 
    3387        4916 :         root->group_pathkeys =
    3388        4916 :             make_pathkeys_for_sortclauses_extended(root,
    3389             :                                                    &root->processed_groupClause,
    3390             :                                                    tlist,
    3391             :                                                    true,
    3392             :                                                    &sortable);
    3393        4916 :         if (!sortable)
    3394             :         {
    3395             :             /* Can't sort; no point in considering aggregate ordering either */
    3396           0 :             root->group_pathkeys = NIL;
    3397           0 :             root->num_groupby_pathkeys = 0;
    3398             :         }
    3399             :         else
    3400             :         {
    3401        4916 :             root->num_groupby_pathkeys = list_length(root->group_pathkeys);
    3402             :             /* If we have ordered aggs, consider adding onto group_pathkeys */
    3403        4916 :             if (root->numOrderedAggs > 0)
    3404        1788 :                 adjust_group_pathkeys_for_groupagg(root);
    3405             :         }
    3406             :     }
    3407             :     else
    3408             :     {
    3409      471334 :         root->group_pathkeys = NIL;
    3410      471334 :         root->num_groupby_pathkeys = 0;
    3411             :     }
    3412             : 
    3413             :     /* We consider only the first (bottom) window in pathkeys logic */
    3414      476978 :     if (activeWindows != NIL)
    3415             :     {
    3416        2294 :         WindowClause *wc = linitial_node(WindowClause, activeWindows);
    3417             : 
    3418        2294 :         root->window_pathkeys = make_pathkeys_for_window(root,
    3419             :                                                          wc,
    3420             :                                                          tlist);
    3421             :     }
    3422             :     else
    3423      474684 :         root->window_pathkeys = NIL;
    3424             : 
    3425             :     /*
    3426             :      * As with GROUP BY, we can discard any DISTINCT items that are proven
    3427             :      * redundant by EquivalenceClass processing.  The non-redundant list is
    3428             :      * kept in root->processed_distinctClause, leaving the original
    3429             :      * parse->distinctClause alone.
    3430             :      */
    3431      476978 :     if (parse->distinctClause)
    3432             :     {
    3433             :         bool        sortable;
    3434             : 
    3435             :         /* Make a copy since pathkey processing can modify the list */
    3436        2182 :         root->processed_distinctClause = list_copy(parse->distinctClause);
    3437        2182 :         root->distinct_pathkeys =
    3438        2182 :             make_pathkeys_for_sortclauses_extended(root,
    3439             :                                                    &root->processed_distinctClause,
    3440             :                                                    tlist,
    3441             :                                                    true,
    3442             :                                                    &sortable);
    3443        2182 :         if (!sortable)
    3444           6 :             root->distinct_pathkeys = NIL;
    3445             :     }
    3446             :     else
    3447      474796 :         root->distinct_pathkeys = NIL;
    3448             : 
    3449      476978 :     root->sort_pathkeys =
    3450      476978 :         make_pathkeys_for_sortclauses(root,
    3451             :                                       parse->sortClause,
    3452             :                                       tlist);
    3453             : 
    3454             :     /* setting setop_pathkeys might be useful to the union planner */
    3455      490762 :     if (qp_extra->setop != NULL &&
    3456       13784 :         set_operation_ordered_results_useful(qp_extra->setop))
    3457       10236 :     {
    3458             :         List       *groupClauses;
    3459             :         bool        sortable;
    3460             : 
    3461       10236 :         groupClauses = generate_setop_child_grouplist(qp_extra->setop, tlist);
    3462             : 
    3463       10236 :         root->setop_pathkeys =
    3464       10236 :             make_pathkeys_for_sortclauses_extended(root,
    3465             :                                                    &groupClauses,
    3466             :                                                    tlist,
    3467             :                                                    false,
    3468             :                                                    &sortable);
    3469       10236 :         if (!sortable)
    3470         152 :             root->setop_pathkeys = NIL;
    3471             :     }
    3472             :     else
    3473      466742 :         root->setop_pathkeys = NIL;
    3474             : 
    3475             :     /*
    3476             :      * Figure out whether we want a sorted result from query_planner.
    3477             :      *
    3478             :      * If we have a sortable GROUP BY clause, then we want a result sorted
    3479             :      * properly for grouping.  Otherwise, if we have window functions to
    3480             :      * evaluate, we try to sort for the first window.  Otherwise, if there's a
    3481             :      * sortable DISTINCT clause that's more rigorous than the ORDER BY clause,
    3482             :      * we try to produce output that's sufficiently well sorted for the
    3483             :      * DISTINCT.  Otherwise, if there is an ORDER BY clause, we want to sort
    3484             :      * by the ORDER BY clause.  Otherwise, if we're a subquery being planned
    3485             :      * for a set operation which can benefit from presorted results and have a
    3486             :      * sortable targetlist, we want to sort by the target list.
    3487             :      *
    3488             :      * Note: if we have both ORDER BY and GROUP BY, and ORDER BY is a superset
    3489             :      * of GROUP BY, it would be tempting to request sort by ORDER BY --- but
    3490             :      * that might just leave us failing to exploit an available sort order at
    3491             :      * all.  Needs more thought.  The choice for DISTINCT versus ORDER BY is
    3492             :      * much easier, since we know that the parser ensured that one is a
    3493             :      * superset of the other.
    3494             :      */
    3495      476978 :     if (root->group_pathkeys)
    3496        5310 :         root->query_pathkeys = root->group_pathkeys;
    3497      471668 :     else if (root->window_pathkeys)
    3498        1982 :         root->query_pathkeys = root->window_pathkeys;
    3499      939372 :     else if (list_length(root->distinct_pathkeys) >
    3500      469686 :              list_length(root->sort_pathkeys))
    3501        1788 :         root->query_pathkeys = root->distinct_pathkeys;
    3502      467898 :     else if (root->sort_pathkeys)
    3503       51344 :         root->query_pathkeys = root->sort_pathkeys;
    3504      416554 :     else if (root->setop_pathkeys != NIL)
    3505        9538 :         root->query_pathkeys = root->setop_pathkeys;
    3506             :     else
    3507      407016 :         root->query_pathkeys = NIL;
    3508      476978 : }
    3509             : 
    3510             : /*
    3511             :  * Estimate number of groups produced by grouping clauses (1 if not grouping)
    3512             :  *
    3513             :  * path_rows: number of output rows from scan/join step
    3514             :  * gd: grouping sets data including list of grouping sets and their clauses
    3515             :  * target_list: target list containing group clause references
    3516             :  *
    3517             :  * If doing grouping sets, we also annotate the gsets data with the estimates
    3518             :  * for each set and each individual rollup list, with a view to later
    3519             :  * determining whether some combination of them could be hashed instead.
    3520             :  */
    3521             : static double
    3522       37210 : get_number_of_groups(PlannerInfo *root,
    3523             :                      double path_rows,
    3524             :                      grouping_sets_data *gd,
    3525             :                      List *target_list)
    3526             : {
    3527       37210 :     Query      *parse = root->parse;
    3528             :     double      dNumGroups;
    3529             : 
    3530       37210 :     if (parse->groupClause)
    3531             :     {
    3532             :         List       *groupExprs;
    3533             : 
    3534        6466 :         if (parse->groupingSets)
    3535             :         {
    3536             :             /* Add up the estimates for each grouping set */
    3537             :             ListCell   *lc;
    3538             : 
    3539             :             Assert(gd);         /* keep Coverity happy */
    3540             : 
    3541         686 :             dNumGroups = 0;
    3542             : 
    3543        1854 :             foreach(lc, gd->rollups)
    3544             :             {
    3545        1168 :                 RollupData *rollup = lfirst_node(RollupData, lc);
    3546             :                 ListCell   *lc2;
    3547             :                 ListCell   *lc3;
    3548             : 
    3549        1168 :                 groupExprs = get_sortgrouplist_exprs(rollup->groupClause,
    3550             :                                                      target_list);
    3551             : 
    3552        1168 :                 rollup->numGroups = 0.0;
    3553             : 
    3554        3488 :                 forboth(lc2, rollup->gsets, lc3, rollup->gsets_data)
    3555             :                 {
    3556        2320 :                     List       *gset = (List *) lfirst(lc2);
    3557        2320 :                     GroupingSetData *gs = lfirst_node(GroupingSetData, lc3);
    3558        2320 :                     double      numGroups = estimate_num_groups(root,
    3559             :                                                                 groupExprs,
    3560             :                                                                 path_rows,
    3561             :                                                                 &gset,
    3562             :                                                                 NULL);
    3563             : 
    3564        2320 :                     gs->numGroups = numGroups;
    3565        2320 :                     rollup->numGroups += numGroups;
    3566             :                 }
    3567             : 
    3568        1168 :                 dNumGroups += rollup->numGroups;
    3569             :             }
    3570             : 
    3571         686 :             if (gd->hash_sets_idx)
    3572             :             {
    3573             :                 ListCell   *lc2;
    3574             : 
    3575          36 :                 gd->dNumHashGroups = 0;
    3576             : 
    3577          36 :                 groupExprs = get_sortgrouplist_exprs(parse->groupClause,
    3578             :                                                      target_list);
    3579             : 
    3580          78 :                 forboth(lc, gd->hash_sets_idx, lc2, gd->unsortable_sets)
    3581             :                 {
    3582          42 :                     List       *gset = (List *) lfirst(lc);
    3583          42 :                     GroupingSetData *gs = lfirst_node(GroupingSetData, lc2);
    3584          42 :                     double      numGroups = estimate_num_groups(root,
    3585             :                                                                 groupExprs,
    3586             :                                                                 path_rows,
    3587             :                                                                 &gset,
    3588             :                                                                 NULL);
    3589             : 
    3590          42 :                     gs->numGroups = numGroups;
    3591          42 :                     gd->dNumHashGroups += numGroups;
    3592             :                 }
    3593             : 
    3594          36 :                 dNumGroups += gd->dNumHashGroups;
    3595             :             }
    3596             :         }
    3597             :         else
    3598             :         {
    3599             :             /* Plain GROUP BY -- estimate based on optimized groupClause */
    3600        5780 :             groupExprs = get_sortgrouplist_exprs(root->processed_groupClause,
    3601             :                                                  target_list);
    3602             : 
    3603        5780 :             dNumGroups = estimate_num_groups(root, groupExprs, path_rows,
    3604             :                                              NULL, NULL);
    3605             :         }
    3606             :     }
    3607       30744 :     else if (parse->groupingSets)
    3608             :     {
    3609             :         /* Empty grouping sets ... one result row for each one */
    3610          42 :         dNumGroups = list_length(parse->groupingSets);
    3611             :     }
    3612       30702 :     else if (parse->hasAggs || root->hasHavingQual)
    3613             :     {
    3614             :         /* Plain aggregation, one result row */
    3615       30702 :         dNumGroups = 1;
    3616             :     }
    3617             :     else
    3618             :     {
    3619             :         /* Not grouping */
    3620           0 :         dNumGroups = 1;
    3621             :     }
    3622             : 
    3623       37210 :     return dNumGroups;
    3624             : }
    3625             : 
    3626             : /*
    3627             :  * create_grouping_paths
    3628             :  *
    3629             :  * Build a new upperrel containing Paths for grouping and/or aggregation.
    3630             :  * Along the way, we also build an upperrel for Paths which are partially
    3631             :  * grouped and/or aggregated.  A partially grouped and/or aggregated path
    3632             :  * needs a FinalizeAggregate node to complete the aggregation.  Currently,
    3633             :  * the only partially grouped paths we build are also partial paths; that
    3634             :  * is, they need a Gather and then a FinalizeAggregate.
    3635             :  *
    3636             :  * input_rel: contains the source-data Paths
    3637             :  * target: the pathtarget for the result Paths to compute
    3638             :  * gd: grouping sets data including list of grouping sets and their clauses
    3639             :  *
    3640             :  * Note: all Paths in input_rel are expected to return the target computed
    3641             :  * by make_group_input_target.
    3642             :  */
    3643             : static RelOptInfo *
    3644       34026 : create_grouping_paths(PlannerInfo *root,
    3645             :                       RelOptInfo *input_rel,
    3646             :                       PathTarget *target,
    3647             :                       bool target_parallel_safe,
    3648             :                       grouping_sets_data *gd)
    3649             : {
    3650       34026 :     Query      *parse = root->parse;
    3651             :     RelOptInfo *grouped_rel;
    3652             :     RelOptInfo *partially_grouped_rel;
    3653             :     AggClauseCosts agg_costs;
    3654             : 
    3655      204156 :     MemSet(&agg_costs, 0, sizeof(AggClauseCosts));
    3656       34026 :     get_agg_clause_costs(root, AGGSPLIT_SIMPLE, &agg_costs);
    3657             : 
    3658             :     /*
    3659             :      * Create grouping relation to hold fully aggregated grouping and/or
    3660             :      * aggregation paths.
    3661             :      */
    3662       34026 :     grouped_rel = make_grouping_rel(root, input_rel, target,
    3663             :                                     target_parallel_safe, parse->havingQual);
    3664             : 
    3665             :     /*
    3666             :      * Create either paths for a degenerate grouping or paths for ordinary
    3667             :      * grouping, as appropriate.
    3668             :      */
    3669       34026 :     if (is_degenerate_grouping(root))
    3670          18 :         create_degenerate_grouping_paths(root, input_rel, grouped_rel);
    3671             :     else
    3672             :     {
    3673       34008 :         int         flags = 0;
    3674             :         GroupPathExtraData extra;
    3675             : 
    3676             :         /*
    3677             :          * Determine whether it's possible to perform sort-based
    3678             :          * implementations of grouping.  (Note that if processed_groupClause
    3679             :          * is empty, grouping_is_sortable() is trivially true, and all the
    3680             :          * pathkeys_contained_in() tests will succeed too, so that we'll
    3681             :          * consider every surviving input path.)
    3682             :          *
    3683             :          * If we have grouping sets, we might be able to sort some but not all
    3684             :          * of them; in this case, we need can_sort to be true as long as we
    3685             :          * must consider any sorted-input plan.
    3686             :          */
    3687       34008 :         if ((gd && gd->rollups != NIL)
    3688       33286 :             || grouping_is_sortable(root->processed_groupClause))
    3689       34002 :             flags |= GROUPING_CAN_USE_SORT;
    3690             : 
    3691             :         /*
    3692             :          * Determine whether we should consider hash-based implementations of
    3693             :          * grouping.
    3694             :          *
    3695             :          * Hashed aggregation only applies if we're grouping. If we have
    3696             :          * grouping sets, some groups might be hashable but others not; in
    3697             :          * this case we set can_hash true as long as there is nothing globally
    3698             :          * preventing us from hashing (and we should therefore consider plans
    3699             :          * with hashes).
    3700             :          *
    3701             :          * Executor doesn't support hashed aggregation with DISTINCT or ORDER
    3702             :          * BY aggregates.  (Doing so would imply storing *all* the input
    3703             :          * values in the hash table, and/or running many sorts in parallel,
    3704             :          * either of which seems like a certain loser.)  We similarly don't
    3705             :          * support ordered-set aggregates in hashed aggregation, but that case
    3706             :          * is also included in the numOrderedAggs count.
    3707             :          *
    3708             :          * Note: grouping_is_hashable() is much more expensive to check than
    3709             :          * the other gating conditions, so we want to do it last.
    3710             :          */
    3711       34008 :         if ((parse->groupClause != NIL &&
    3712        7830 :              root->numOrderedAggs == 0 &&
    3713        3778 :              (gd ? gd->any_hashable : grouping_is_hashable(root->processed_groupClause))))
    3714        3774 :             flags |= GROUPING_CAN_USE_HASH;
    3715             : 
    3716             :         /*
    3717             :          * Determine whether partial aggregation is possible.
    3718             :          */
    3719       34008 :         if (can_partial_agg(root))
    3720       30302 :             flags |= GROUPING_CAN_PARTIAL_AGG;
    3721             : 
    3722       34008 :         extra.flags = flags;
    3723       34008 :         extra.target_parallel_safe = target_parallel_safe;
    3724       34008 :         extra.havingQual = parse->havingQual;
    3725       34008 :         extra.targetList = parse->targetList;
    3726       34008 :         extra.partial_costs_set = false;
    3727             : 
    3728             :         /*
    3729             :          * Determine whether partitionwise aggregation is in theory possible.
    3730             :          * It can be disabled by the user, and for now, we don't try to
    3731             :          * support grouping sets.  create_ordinary_grouping_paths() will check
    3732             :          * additional conditions, such as whether input_rel is partitioned.
    3733             :          */
    3734       34008 :         if (enable_partitionwise_aggregate && !parse->groupingSets)
    3735         448 :             extra.patype = PARTITIONWISE_AGGREGATE_FULL;
    3736             :         else
    3737       33560 :             extra.patype = PARTITIONWISE_AGGREGATE_NONE;
    3738             : 
    3739       34008 :         create_ordinary_grouping_paths(root, input_rel, grouped_rel,
    3740             :                                        &agg_costs, gd, &extra,
    3741             :                                        &partially_grouped_rel);
    3742             :     }
    3743             : 
    3744       34018 :     set_cheapest(grouped_rel);
    3745       34018 :     return grouped_rel;
    3746             : }
    3747             : 
    3748             : /*
    3749             :  * make_grouping_rel
    3750             :  *
    3751             :  * Create a new grouping rel and set basic properties.
    3752             :  *
    3753             :  * input_rel represents the underlying scan/join relation.
    3754             :  * target is the output expected from the grouping relation.
    3755             :  */
    3756             : static RelOptInfo *
    3757       35424 : make_grouping_rel(PlannerInfo *root, RelOptInfo *input_rel,
    3758             :                   PathTarget *target, bool target_parallel_safe,
    3759             :                   Node *havingQual)
    3760             : {
    3761             :     RelOptInfo *grouped_rel;
    3762             : 
    3763       35424 :     if (IS_OTHER_REL(input_rel))
    3764             :     {
    3765        1398 :         grouped_rel = fetch_upper_rel(root, UPPERREL_GROUP_AGG,
    3766             :                                       input_rel->relids);
    3767        1398 :         grouped_rel->reloptkind = RELOPT_OTHER_UPPER_REL;
    3768             :     }
    3769             :     else
    3770             :     {
    3771             :         /*
    3772             :          * By tradition, the relids set for the main grouping relation is
    3773             :          * NULL.  (This could be changed, but might require adjustments
    3774             :          * elsewhere.)
    3775             :          */
    3776       34026 :         grouped_rel = fetch_upper_rel(root, UPPERREL_GROUP_AGG, NULL);
    3777             :     }
    3778             : 
    3779             :     /* Set target. */
    3780       35424 :     grouped_rel->reltarget = target;
    3781             : 
    3782             :     /*
    3783             :      * If the input relation is not parallel-safe, then the grouped relation
    3784             :      * can't be parallel-safe, either.  Otherwise, it's parallel-safe if the
    3785             :      * target list and HAVING quals are parallel-safe.
    3786             :      */
    3787       60752 :     if (input_rel->consider_parallel && target_parallel_safe &&
    3788       25328 :         is_parallel_safe(root, (Node *) havingQual))
    3789       25310 :         grouped_rel->consider_parallel = true;
    3790             : 
    3791             :     /*
    3792             :      * If the input rel belongs to a single FDW, so does the grouped rel.
    3793             :      */
    3794       35424 :     grouped_rel->serverid = input_rel->serverid;
    3795       35424 :     grouped_rel->userid = input_rel->userid;
    3796       35424 :     grouped_rel->useridiscurrent = input_rel->useridiscurrent;
    3797       35424 :     grouped_rel->fdwroutine = input_rel->fdwroutine;
    3798             : 
    3799       35424 :     return grouped_rel;
    3800             : }
    3801             : 
    3802             : /*
    3803             :  * is_degenerate_grouping
    3804             :  *
    3805             :  * A degenerate grouping is one in which the query has a HAVING qual and/or
    3806             :  * grouping sets, but no aggregates and no GROUP BY (which implies that the
    3807             :  * grouping sets are all empty).
    3808             :  */
    3809             : static bool
    3810       34026 : is_degenerate_grouping(PlannerInfo *root)
    3811             : {
    3812       34026 :     Query      *parse = root->parse;
    3813             : 
    3814       32938 :     return (root->hasHavingQual || parse->groupingSets) &&
    3815       66964 :         !parse->hasAggs && parse->groupClause == NIL;
    3816             : }
    3817             : 
    3818             : /*
    3819             :  * create_degenerate_grouping_paths
    3820             :  *
    3821             :  * When the grouping is degenerate (see is_degenerate_grouping), we are
    3822             :  * supposed to emit either zero or one row for each grouping set depending on
    3823             :  * whether HAVING succeeds.  Furthermore, there cannot be any variables in
    3824             :  * either HAVING or the targetlist, so we actually do not need the FROM table
    3825             :  * at all! We can just throw away the plan-so-far and generate a Result node.
    3826             :  * This is a sufficiently unusual corner case that it's not worth contorting
    3827             :  * the structure of this module to avoid having to generate the earlier paths
    3828             :  * in the first place.
    3829             :  */
    3830             : static void
    3831          18 : create_degenerate_grouping_paths(PlannerInfo *root, RelOptInfo *input_rel,
    3832             :                                  RelOptInfo *grouped_rel)
    3833             : {
    3834          18 :     Query      *parse = root->parse;
    3835             :     int         nrows;
    3836             :     Path       *path;
    3837             : 
    3838          18 :     nrows = list_length(parse->groupingSets);
    3839          18 :     if (nrows > 1)
    3840             :     {
    3841             :         /*
    3842             :          * Doesn't seem worthwhile writing code to cons up a generate_series
    3843             :          * or a values scan to emit multiple rows. Instead just make N clones
    3844             :          * and append them.  (With a volatile HAVING clause, this means you
    3845             :          * might get between 0 and N output rows. Offhand I think that's
    3846             :          * desired.)
    3847             :          */
    3848           0 :         List       *paths = NIL;
    3849             : 
    3850           0 :         while (--nrows >= 0)
    3851             :         {
    3852             :             path = (Path *)
    3853           0 :                 create_group_result_path(root, grouped_rel,
    3854           0 :                                          grouped_rel->reltarget,
    3855           0 :                                          (List *) parse->havingQual);
    3856           0 :             paths = lappend(paths, path);
    3857             :         }
    3858             :         path = (Path *)
    3859           0 :             create_append_path(root,
    3860             :                                grouped_rel,
    3861             :                                paths,
    3862             :                                NIL,
    3863             :                                NIL,
    3864             :                                NULL,
    3865             :                                0,
    3866             :                                false,
    3867             :                                -1);
    3868             :     }
    3869             :     else
    3870             :     {
    3871             :         /* No grouping sets, or just one, so one output row */
    3872             :         path = (Path *)
    3873          18 :             create_group_result_path(root, grouped_rel,
    3874          18 :                                      grouped_rel->reltarget,
    3875          18 :                                      (List *) parse->havingQual);
    3876             :     }
    3877             : 
    3878          18 :     add_path(grouped_rel, path);
    3879          18 : }
    3880             : 
    3881             : /*
    3882             :  * create_ordinary_grouping_paths
    3883             :  *
    3884             :  * Create grouping paths for the ordinary (that is, non-degenerate) case.
    3885             :  *
    3886             :  * We need to consider sorted and hashed aggregation in the same function,
    3887             :  * because otherwise (1) it would be harder to throw an appropriate error
    3888             :  * message if neither way works, and (2) we should not allow hashtable size
    3889             :  * considerations to dissuade us from using hashing if sorting is not possible.
    3890             :  *
    3891             :  * *partially_grouped_rel_p will be set to the partially grouped rel which this
    3892             :  * function creates, or to NULL if it doesn't create one.
    3893             :  */
    3894             : static void
    3895       35406 : create_ordinary_grouping_paths(PlannerInfo *root, RelOptInfo *input_rel,
    3896             :                                RelOptInfo *grouped_rel,
    3897             :                                const AggClauseCosts *agg_costs,
    3898             :                                grouping_sets_data *gd,
    3899             :                                GroupPathExtraData *extra,
    3900             :                                RelOptInfo **partially_grouped_rel_p)
    3901             : {
    3902       35406 :     Path       *cheapest_path = input_rel->cheapest_total_path;
    3903       35406 :     RelOptInfo *partially_grouped_rel = NULL;
    3904             :     double      dNumGroups;
    3905       35406 :     PartitionwiseAggregateType patype = PARTITIONWISE_AGGREGATE_NONE;
    3906             : 
    3907             :     /*
    3908             :      * If this is the topmost grouping relation or if the parent relation is
    3909             :      * doing some form of partitionwise aggregation, then we may be able to do
    3910             :      * it at this level also.  However, if the input relation is not
    3911             :      * partitioned, partitionwise aggregate is impossible.
    3912             :      */
    3913       35406 :     if (extra->patype != PARTITIONWISE_AGGREGATE_NONE &&
    3914        1846 :         IS_PARTITIONED_REL(input_rel))
    3915             :     {
    3916             :         /*
    3917             :          * If this is the topmost relation or if the parent relation is doing
    3918             :          * full partitionwise aggregation, then we can do full partitionwise
    3919             :          * aggregation provided that the GROUP BY clause contains all of the
    3920             :          * partitioning columns at this level.  Otherwise, we can do at most
    3921             :          * partial partitionwise aggregation.  But if partial aggregation is
    3922             :          * not supported in general then we can't use it for partitionwise
    3923             :          * aggregation either.
    3924             :          *
    3925             :          * Check parse->groupClause not processed_groupClause, because it's
    3926             :          * okay if some of the partitioning columns were proved redundant.
    3927             :          */
    3928        1064 :         if (extra->patype == PARTITIONWISE_AGGREGATE_FULL &&
    3929         508 :             group_by_has_partkey(input_rel, extra->targetList,
    3930         508 :                                  root->parse->groupClause))
    3931         284 :             patype = PARTITIONWISE_AGGREGATE_FULL;
    3932         272 :         else if ((extra->flags & GROUPING_CAN_PARTIAL_AGG) != 0)
    3933         230 :             patype = PARTITIONWISE_AGGREGATE_PARTIAL;
    3934             :         else
    3935          42 :             patype = PARTITIONWISE_AGGREGATE_NONE;
    3936             :     }
    3937             : 
    3938             :     /*
    3939             :      * Before generating paths for grouped_rel, we first generate any possible
    3940             :      * partially grouped paths; that way, later code can easily consider both
    3941             :      * parallel and non-parallel approaches to grouping.
    3942             :      */
    3943       35406 :     if ((extra->flags & GROUPING_CAN_PARTIAL_AGG) != 0)
    3944             :     {
    3945             :         bool        force_rel_creation;
    3946             : 
    3947             :         /*
    3948             :          * If we're doing partitionwise aggregation at this level, force
    3949             :          * creation of a partially_grouped_rel so we can add partitionwise
    3950             :          * paths to it.
    3951             :          */
    3952       31628 :         force_rel_creation = (patype == PARTITIONWISE_AGGREGATE_PARTIAL);
    3953             : 
    3954             :         partially_grouped_rel =
    3955       31628 :             create_partial_grouping_paths(root,
    3956             :                                           grouped_rel,
    3957             :                                           input_rel,
    3958             :                                           gd,
    3959             :                                           extra,
    3960             :                                           force_rel_creation);
    3961             :     }
    3962             : 
    3963             :     /* Set out parameter. */
    3964       35406 :     *partially_grouped_rel_p = partially_grouped_rel;
    3965             : 
    3966             :     /* Apply partitionwise aggregation technique, if possible. */
    3967       35406 :     if (patype != PARTITIONWISE_AGGREGATE_NONE)
    3968         514 :         create_partitionwise_grouping_paths(root, input_rel, grouped_rel,
    3969             :                                             partially_grouped_rel, agg_costs,
    3970             :                                             gd, patype, extra);
    3971             : 
    3972             :     /* If we are doing partial aggregation only, return. */
    3973       35406 :     if (extra->patype == PARTITIONWISE_AGGREGATE_PARTIAL)
    3974             :     {
    3975             :         Assert(partially_grouped_rel);
    3976             : 
    3977         594 :         if (partially_grouped_rel->pathlist)
    3978         594 :             set_cheapest(partially_grouped_rel);
    3979             : 
    3980         594 :         return;
    3981             :     }
    3982             : 
    3983             :     /* Gather any partially grouped partial paths. */
    3984       34812 :     if (partially_grouped_rel && partially_grouped_rel->partial_pathlist)
    3985             :     {
    3986        1468 :         gather_grouping_paths(root, partially_grouped_rel);
    3987        1468 :         set_cheapest(partially_grouped_rel);
    3988             :     }
    3989             : 
    3990             :     /*
    3991             :      * Estimate number of groups.
    3992             :      */
    3993       34812 :     dNumGroups = get_number_of_groups(root,
    3994             :                                       cheapest_path->rows,
    3995             :                                       gd,
    3996             :                                       extra->targetList);
    3997             : 
    3998             :     /* Build final grouping paths */
    3999       34812 :     add_paths_to_grouping_rel(root, input_rel, grouped_rel,
    4000             :                               partially_grouped_rel, agg_costs, gd,
    4001             :                               dNumGroups, extra);
    4002             : 
    4003             :     /* Give a helpful error if we failed to find any implementation */
    4004       34812 :     if (grouped_rel->pathlist == NIL)
    4005           6 :         ereport(ERROR,
    4006             :                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
    4007             :                  errmsg("could not implement GROUP BY"),
    4008             :                  errdetail("Some of the datatypes only support hashing, while others only support sorting.")));
    4009             : 
    4010             :     /*
    4011             :      * If there is an FDW that's responsible for all baserels of the query,
    4012             :      * let it consider adding ForeignPaths.
    4013             :      */
    4014       34806 :     if (grouped_rel->fdwroutine &&
    4015         326 :         grouped_rel->fdwroutine->GetForeignUpperPaths)
    4016         326 :         grouped_rel->fdwroutine->GetForeignUpperPaths(root, UPPERREL_GROUP_AGG,
    4017             :                                                       input_rel, grouped_rel,
    4018             :                                                       extra);
    4019             : 
    4020             :     /* Let extensions possibly add some more paths */
    4021       34804 :     if (create_upper_paths_hook)
    4022           0 :         (*create_upper_paths_hook) (root, UPPERREL_GROUP_AGG,
    4023             :                                     input_rel, grouped_rel,
    4024             :                                     extra);
    4025             : }
    4026             : 
    4027             : /*
    4028             :  * For a given input path, consider the possible ways of doing grouping sets on
    4029             :  * it, by combinations of hashing and sorting.  This can be called multiple
    4030             :  * times, so it's important that it not scribble on input.  No result is
    4031             :  * returned, but any generated paths are added to grouped_rel.
    4032             :  */
    4033             : static void
    4034        1444 : consider_groupingsets_paths(PlannerInfo *root,
    4035             :                             RelOptInfo *grouped_rel,
    4036             :                             Path *path,
    4037             :                             bool is_sorted,
    4038             :                             bool can_hash,
    4039             :                             grouping_sets_data *gd,
    4040             :                             const AggClauseCosts *agg_costs,
    4041             :                             double dNumGroups)
    4042             : {
    4043        1444 :     Query      *parse = root->parse;
    4044        1444 :     Size        hash_mem_limit = get_hash_memory_limit();
    4045             : 
    4046             :     /*
    4047             :      * If we're not being offered sorted input, then only consider plans that
    4048             :      * can be done entirely by hashing.
    4049             :      *
    4050             :      * We can hash everything if it looks like it'll fit in hash_mem. But if
    4051             :      * the input is actually sorted despite not being advertised as such, we
    4052             :      * prefer to make use of that in order to use less memory.
    4053             :      *
    4054             :      * If none of the grouping sets are sortable, then ignore the hash_mem
    4055             :      * limit and generate a path anyway, since otherwise we'll just fail.
    4056             :      */
    4057        1444 :     if (!is_sorted)
    4058             :     {
    4059         650 :         List       *new_rollups = NIL;
    4060         650 :         RollupData *unhashed_rollup = NULL;
    4061             :         List       *sets_data;
    4062         650 :         List       *empty_sets_data = NIL;
    4063         650 :         List       *empty_sets = NIL;
    4064             :         ListCell   *lc;
    4065         650 :         ListCell   *l_start = list_head(gd->rollups);
    4066         650 :         AggStrategy strat = AGG_HASHED;
    4067             :         double      hashsize;
    4068         650 :         double      exclude_groups = 0.0;
    4069             : 
    4070             :         Assert(can_hash);
    4071             : 
    4072             :         /*
    4073             :          * If the input is coincidentally sorted usefully (which can happen
    4074             :          * even if is_sorted is false, since that only means that our caller
    4075             :          * has set up the sorting for us), then save some hashtable space by
    4076             :          * making use of that. But we need to watch out for degenerate cases:
    4077             :          *
    4078             :          * 1) If there are any empty grouping sets, then group_pathkeys might
    4079             :          * be NIL if all non-empty grouping sets are unsortable. In this case,
    4080             :          * there will be a rollup containing only empty groups, and the
    4081             :          * pathkeys_contained_in test is vacuously true; this is ok.
    4082             :          *
    4083             :          * XXX: the above relies on the fact that group_pathkeys is generated
    4084             :          * from the first rollup. If we add the ability to consider multiple
    4085             :          * sort orders for grouping input, this assumption might fail.
    4086             :          *
    4087             :          * 2) If there are no empty sets and only unsortable sets, then the
    4088             :          * rollups list will be empty (and thus l_start == NULL), and
    4089             :          * group_pathkeys will be NIL; we must ensure that the vacuously-true
    4090             :          * pathkeys_contained_in test doesn't cause us to crash.
    4091             :          */
    4092        1294 :         if (l_start != NULL &&
    4093         644 :             pathkeys_contained_in(root->group_pathkeys, path->pathkeys))
    4094             :         {
    4095          24 :             unhashed_rollup = lfirst_node(RollupData, l_start);
    4096          24 :             exclude_groups = unhashed_rollup->numGroups;
    4097          24 :             l_start = lnext(gd->rollups, l_start);
    4098             :         }
    4099             : 
    4100         650 :         hashsize = estimate_hashagg_tablesize(root,
    4101             :                                               path,
    4102             :                                               agg_costs,
    4103             :                                               dNumGroups - exclude_groups);
    4104             : 
    4105             :         /*
    4106             :          * gd->rollups is empty if we have only unsortable columns to work
    4107             :          * with.  Override hash_mem in that case; otherwise, we'll rely on the
    4108             :          * sorted-input case to generate usable mixed paths.
    4109             :          */
    4110         650 :         if (hashsize > hash_mem_limit && gd->rollups)
    4111          18 :             return;             /* nope, won't fit */
    4112             : 
    4113             :         /*
    4114             :          * We need to burst the existing rollups list into individual grouping
    4115             :          * sets and recompute a groupClause for each set.
    4116             :          */
    4117         632 :         sets_data = list_copy(gd->unsortable_sets);
    4118             : 
    4119        1596 :         for_each_cell(lc, gd->rollups, l_start)
    4120             :         {
    4121         988 :             RollupData *rollup = lfirst_node(RollupData, lc);
    4122             : 
    4123             :             /*
    4124             :              * If we find an unhashable rollup that's not been skipped by the
    4125             :              * "actually sorted" check above, we can't cope; we'd need sorted
    4126             :              * input (with a different sort order) but we can't get that here.
    4127             :              * So bail out; we'll get a valid path from the is_sorted case
    4128             :              * instead.
    4129             :              *
    4130             :              * The mere presence of empty grouping sets doesn't make a rollup
    4131             :              * unhashable (see preprocess_grouping_sets), we handle those
    4132             :              * specially below.
    4133             :              */
    4134         988 :             if (!rollup->hashable)
    4135          24 :                 return;
    4136             : 
    4137         964 :             sets_data = list_concat(sets_data, rollup->gsets_data);
    4138             :         }
    4139        2682 :         foreach(lc, sets_data)
    4140             :         {
    4141        2074 :             GroupingSetData *gs = lfirst_node(GroupingSetData, lc);
    4142        2074 :             List       *gset = gs->set;
    4143             :             RollupData *rollup;
    4144             : 
    4145        2074 :             if (gset == NIL)
    4146             :             {
    4147             :                 /* Empty grouping sets can't be hashed. */
    4148         448 :                 empty_sets_data = lappend(empty_sets_data, gs);
    4149         448 :                 empty_sets = lappend(empty_sets, NIL);
    4150             :             }
    4151             :             else
    4152             :             {
    4153        1626 :                 rollup = makeNode(RollupData);
    4154             : 
    4155        1626 :                 rollup->groupClause = groupclause_apply_groupingset(root, gset);
    4156        1626 :                 rollup->gsets_data = list_make1(gs);
    4157        1626 :                 rollup->gsets = remap_to_groupclause_idx(rollup->groupClause,
    4158             :                                                          rollup->gsets_data,
    4159             :                                                          gd->tleref_to_colnum_map);
    4160        1626 :                 rollup->numGroups = gs->numGroups;
    4161        1626 :                 rollup->hashable = true;
    4162        1626 :                 rollup->is_hashed = true;
    4163        1626 :                 new_rollups = lappend(new_rollups, rollup);
    4164             :             }
    4165             :         }
    4166             : 
    4167             :         /*
    4168             :          * If we didn't find anything nonempty to hash, then bail.  We'll
    4169             :          * generate a path from the is_sorted case.
    4170             :          */
    4171         608 :         if (new_rollups == NIL)
    4172           0 :             return;
    4173             : 
    4174             :         /*
    4175             :          * If there were empty grouping sets they should have been in the
    4176             :          * first rollup.
    4177             :          */
    4178             :         Assert(!unhashed_rollup || !empty_sets);
    4179             : 
    4180         608 :         if (unhashed_rollup)
    4181             :         {
    4182          24 :             new_rollups = lappend(new_rollups, unhashed_rollup);
    4183          24 :             strat = AGG_MIXED;
    4184             :         }
    4185         584 :         else if (empty_sets)
    4186             :         {
    4187         400 :             RollupData *rollup = makeNode(RollupData);
    4188             : 
    4189         400 :             rollup->groupClause = NIL;
    4190         400 :             rollup->gsets_data = empty_sets_data;
    4191         400 :             rollup->gsets = empty_sets;
    4192         400 :             rollup->numGroups = list_length(empty_sets);
    4193         400 :             rollup->hashable = false;
    4194         400 :             rollup->is_hashed = false;
    4195         400 :             new_rollups = lappend(new_rollups, rollup);
    4196         400 :             strat = AGG_MIXED;
    4197             :         }
    4198             : 
    4199         608 :         add_path(grouped_rel, (Path *)
    4200         608 :                  create_groupingsets_path(root,
    4201             :                                           grouped_rel,
    4202             :                                           path,
    4203         608 :                                           (List *) parse->havingQual,
    4204             :                                           strat,
    4205             :                                           new_rollups,
    4206             :                                           agg_costs));
    4207         608 :         return;
    4208             :     }
    4209             : 
    4210             :     /*
    4211             :      * If we have sorted input but nothing we can do with it, bail.
    4212             :      */
    4213         794 :     if (gd->rollups == NIL)
    4214           0 :         return;
    4215             : 
    4216             :     /*
    4217             :      * Given sorted input, we try and make two paths: one sorted and one mixed
    4218             :      * sort/hash. (We need to try both because hashagg might be disabled, or
    4219             :      * some columns might not be sortable.)
    4220             :      *
    4221             :      * can_hash is passed in as false if some obstacle elsewhere (such as
    4222             :      * ordered aggs) means that we shouldn't consider hashing at all.
    4223             :      */
    4224         794 :     if (can_hash && gd->any_hashable)
    4225             :     {
    4226         716 :         List       *rollups = NIL;
    4227         716 :         List       *hash_sets = list_copy(gd->unsortable_sets);
    4228         716 :         double      availspace = hash_mem_limit;
    4229             :         ListCell   *lc;
    4230             : 
    4231             :         /*
    4232             :          * Account first for space needed for groups we can't sort at all.
    4233             :          */
    4234         716 :         availspace -= estimate_hashagg_tablesize(root,
    4235             :                                                  path,
    4236             :                                                  agg_costs,
    4237             :                                                  gd->dNumHashGroups);
    4238             : 
    4239         716 :         if (availspace > 0 && list_length(gd->rollups) > 1)
    4240             :         {
    4241             :             double      scale;
    4242         396 :             int         num_rollups = list_length(gd->rollups);
    4243             :             int         k_capacity;
    4244         396 :             int        *k_weights = palloc(num_rollups * sizeof(int));
    4245         396 :             Bitmapset  *hash_items = NULL;
    4246             :             int         i;
    4247             : 
    4248             :             /*
    4249             :              * We treat this as a knapsack problem: the knapsack capacity
    4250             :              * represents hash_mem, the item weights are the estimated memory
    4251             :              * usage of the hashtables needed to implement a single rollup,
    4252             :              * and we really ought to use the cost saving as the item value;
    4253             :              * however, currently the costs assigned to sort nodes don't
    4254             :              * reflect the comparison costs well, and so we treat all items as
    4255             :              * of equal value (each rollup we hash instead saves us one sort).
    4256             :              *
    4257             :              * To use the discrete knapsack, we need to scale the values to a
    4258             :              * reasonably small bounded range.  We choose to allow a 5% error
    4259             :              * margin; we have no more than 4096 rollups in the worst possible
    4260             :              * case, which with a 5% error margin will require a bit over 42MB
    4261             :              * of workspace. (Anyone wanting to plan queries that complex had
    4262             :              * better have the memory for it.  In more reasonable cases, with
    4263             :              * no more than a couple of dozen rollups, the memory usage will
    4264             :              * be negligible.)
    4265             :              *
    4266             :              * k_capacity is naturally bounded, but we clamp the values for
    4267             :              * scale and weight (below) to avoid overflows or underflows (or
    4268             :              * uselessly trying to use a scale factor less than 1 byte).
    4269             :              */
    4270         396 :             scale = Max(availspace / (20.0 * num_rollups), 1.0);
    4271         396 :             k_capacity = (int) floor(availspace / scale);
    4272             : 
    4273             :             /*
    4274             :              * We leave the first rollup out of consideration since it's the
    4275             :              * one that matches the input sort order.  We assign indexes "i"
    4276             :              * to only those entries considered for hashing; the second loop,
    4277             :              * below, must use the same condition.
    4278             :              */
    4279         396 :             i = 0;
    4280        1008 :             for_each_from(lc, gd->rollups, 1)
    4281             :             {
    4282         612 :                 RollupData *rollup = lfirst_node(RollupData, lc);
    4283             : 
    4284         612 :                 if (rollup->hashable)
    4285             :                 {
    4286         612 :                     double      sz = estimate_hashagg_tablesize(root,
    4287             :                                                                 path,
    4288             :                                                                 agg_costs,
    4289             :                                                                 rollup->numGroups);
    4290             : 
    4291             :                     /*
    4292             :                      * If sz is enormous, but hash_mem (and hence scale) is
    4293             :                      * small, avoid integer overflow here.
    4294             :                      */
    4295         612 :                     k_weights[i] = (int) Min(floor(sz / scale),
    4296             :                                              k_capacity + 1.0);
    4297         612 :                     ++i;
    4298             :                 }
    4299             :             }
    4300             : 
    4301             :             /*
    4302             :              * Apply knapsack algorithm; compute the set of items which
    4303             :              * maximizes the value stored (in this case the number of sorts
    4304             :              * saved) while keeping the total size (approximately) within
    4305             :              * capacity.
    4306             :              */
    4307         396 :             if (i > 0)
    4308         396 :                 hash_items = DiscreteKnapsack(k_capacity, i, k_weights, NULL);
    4309             : 
    4310         396 :             if (!bms_is_empty(hash_items))
    4311             :             {
    4312         396 :                 rollups = list_make1(linitial(gd->rollups));
    4313             : 
    4314         396 :                 i = 0;
    4315        1008 :                 for_each_from(lc, gd->rollups, 1)
    4316             :                 {
    4317         612 :                     RollupData *rollup = lfirst_node(RollupData, lc);
    4318             : 
    4319         612 :                     if (rollup->hashable)
    4320             :                     {
    4321         612 :                         if (bms_is_member(i, hash_items))
    4322         576 :                             hash_sets = list_concat(hash_sets,
    4323         576 :                                                     rollup->gsets_data);
    4324             :                         else
    4325          36 :                             rollups = lappend(rollups, rollup);
    4326         612 :                         ++i;
    4327             :                     }
    4328             :                     else
    4329           0 :                         rollups = lappend(rollups, rollup);
    4330             :                 }
    4331             :             }
    4332             :         }
    4333             : 
    4334         716 :         if (!rollups && hash_sets)
    4335          24 :             rollups = list_copy(gd->rollups);
    4336             : 
    4337        1432 :         foreach(lc, hash_sets)
    4338             :         {
    4339         716 :             GroupingSetData *gs = lfirst_node(GroupingSetData, lc);
    4340         716 :             RollupData *rollup = makeNode(RollupData);
    4341             : 
    4342             :             Assert(gs->set != NIL);
    4343             : 
    4344         716 :             rollup->groupClause = groupclause_apply_groupingset(root, gs->set);
    4345         716 :             rollup->gsets_data = list_make1(gs);
    4346         716 :             rollup->gsets = remap_to_groupclause_idx(rollup->groupClause,
    4347             :                                                      rollup->gsets_data,
    4348             :                                                      gd->tleref_to_colnum_map);
    4349         716 :             rollup->numGroups = gs->numGroups;
    4350         716 :             rollup->hashable = true;
    4351         716 :             rollup->is_hashed = true;
    4352         716 :             rollups = lcons(rollup, rollups);
    4353             :         }
    4354             : 
    4355         716 :         if (rollups)
    4356             :         {
    4357         420 :             add_path(grouped_rel, (Path *)
    4358         420 :                      create_groupingsets_path(root,
    4359             :                                               grouped_rel,
    4360             :                                               path,
    4361         420 :                                               (List *) parse->havingQual,
    4362             :                                               AGG_MIXED,
    4363             :                                               rollups,
    4364             :                                               agg_costs));
    4365             :         }
    4366             :     }
    4367             : 
    4368             :     /*
    4369             :      * Now try the simple sorted case.
    4370             :      */
    4371         794 :     if (!gd->unsortable_sets)
    4372         764 :         add_path(grouped_rel, (Path *)
    4373         764 :                  create_groupingsets_path(root,
    4374             :                                           grouped_rel,
    4375             :                                           path,
    4376         764 :                                           (List *) parse->havingQual,
    4377             :                                           AGG_SORTED,
    4378             :                                           gd->rollups,
    4379             :                                           agg_costs));
    4380             : }
    4381             : 
    4382             : /*
    4383             :  * create_window_paths
    4384             :  *
    4385             :  * Build a new upperrel containing Paths for window-function evaluation.
    4386             :  *
    4387             :  * input_rel: contains the source-data Paths
    4388             :  * input_target: result of make_window_input_target
    4389             :  * output_target: what the topmost WindowAggPath should return
    4390             :  * wflists: result of find_window_functions
    4391             :  * activeWindows: result of select_active_windows
    4392             :  *
    4393             :  * Note: all Paths in input_rel are expected to return input_target.
    4394             :  */
    4395             : static RelOptInfo *
    4396        2294 : create_window_paths(PlannerInfo *root,
    4397             :                     RelOptInfo *input_rel,
    4398             :                     PathTarget *input_target,
    4399             :                     PathTarget *output_target,
    4400             :                     bool output_target_parallel_safe,
    4401             :                     WindowFuncLists *wflists,
    4402             :                     List *activeWindows)
    4403             : {
    4404             :     RelOptInfo *window_rel;
    4405             :     ListCell   *lc;
    4406             : 
    4407             :     /* For now, do all work in the (WINDOW, NULL) upperrel */
    4408        2294 :     window_rel = fetch_upper_rel(root, UPPERREL_WINDOW, NULL);
    4409             : 
    4410             :     /*
    4411             :      * If the input relation is not parallel-safe, then the window relation
    4412             :      * can't be parallel-safe, either.  Otherwise, we need to examine the
    4413             :      * target list and active windows for non-parallel-safe constructs.
    4414             :      */
    4415        2294 :     if (input_rel->consider_parallel && output_target_parallel_safe &&
    4416           0 :         is_parallel_safe(root, (Node *) activeWindows))
    4417           0 :         window_rel->consider_parallel = true;
    4418             : 
    4419             :     /*
    4420             :      * If the input rel belongs to a single FDW, so does the window rel.
    4421             :      */
    4422        2294 :     window_rel->serverid = input_rel->serverid;
    4423        2294 :     window_rel->userid = input_rel->userid;
    4424        2294 :     window_rel->useridiscurrent = input_rel->useridiscurrent;
    4425        2294 :     window_rel->fdwroutine = input_rel->fdwroutine;
    4426             : 
    4427             :     /*
    4428             :      * Consider computing window functions starting from the existing
    4429             :      * cheapest-total path (which will likely require a sort) as well as any
    4430             :      * existing paths that satisfy or partially satisfy root->window_pathkeys.
    4431             :      */
    4432        4888 :     foreach(lc, input_rel->pathlist)
    4433             :     {
    4434        2594 :         Path       *path = (Path *) lfirst(lc);
    4435             :         int         presorted_keys;
    4436             : 
    4437        2894 :         if (path == input_rel->cheapest_total_path ||
    4438         300 :             pathkeys_count_contained_in(root->window_pathkeys, path->pathkeys,
    4439         132 :                                         &presorted_keys) ||
    4440         132 :             presorted_keys > 0)
    4441        2480 :             create_one_window_path(root,
    4442             :                                    window_rel,
    4443             :                                    path,
    4444             :                                    input_target,
    4445             :                                    output_target,
    4446             :                                    wflists,
    4447             :                                    activeWindows);
    4448             :     }
    4449             : 
    4450             :     /*
    4451             :      * If there is an FDW that's responsible for all baserels of the query,
    4452             :      * let it consider adding ForeignPaths.
    4453             :      */
    4454        2294 :     if (window_rel->fdwroutine &&
    4455          12 :         window_rel->fdwroutine->GetForeignUpperPaths)
    4456          12 :         window_rel->fdwroutine->GetForeignUpperPaths(root, UPPERREL_WINDOW,
    4457             :                                                      input_rel, window_rel,
    4458             :                                                      NULL);
    4459             : 
    4460             :     /* Let extensions possibly add some more paths */
    4461        2294 :     if (create_upper_paths_hook)
    4462           0 :         (*create_upper_paths_hook) (root, UPPERREL_WINDOW,
    4463             :                                     input_rel, window_rel, NULL);
    4464             : 
    4465             :     /* Now choose the best path(s) */
    4466        2294 :     set_cheapest(window_rel);
    4467             : 
    4468        2294 :     return window_rel;
    4469             : }
    4470             : 
    4471             : /*
    4472             :  * Stack window-function implementation steps atop the given Path, and
    4473             :  * add the result to window_rel.
    4474             :  *
    4475             :  * window_rel: upperrel to contain result
    4476             :  * path: input Path to use (must return input_target)
    4477             :  * input_target: result of make_window_input_target
    4478             :  * output_target: what the topmost WindowAggPath should return
    4479             :  * wflists: result of find_window_functions
    4480             :  * activeWindows: result of select_active_windows
    4481             :  */
    4482             : static void
    4483        2480 : create_one_window_path(PlannerInfo *root,
    4484             :                        RelOptInfo *window_rel,
    4485             :                        Path *path,
    4486             :                        PathTarget *input_target,
    4487             :                        PathTarget *output_target,
    4488             :                        WindowFuncLists *wflists,
    4489             :                        List *activeWindows)
    4490             : {
    4491             :     PathTarget *window_target;
    4492             :     ListCell   *l;
    4493        2480 :     List       *topqual = NIL;
    4494             : 
    4495             :     /*
    4496             :      * Since each window clause could require a different sort order, we stack
    4497             :      * up a WindowAgg node for each clause, with sort steps between them as
    4498             :      * needed.  (We assume that select_active_windows chose a good order for
    4499             :      * executing the clauses in.)
    4500             :      *
    4501             :      * input_target should contain all Vars and Aggs needed for the result.
    4502             :      * (In some cases we wouldn't need to propagate all of these all the way
    4503             :      * to the top, since they might only be needed as inputs to WindowFuncs.
    4504             :      * It's probably not worth trying to optimize that though.)  It must also
    4505             :      * contain all window partitioning and sorting expressions, to ensure
    4506             :      * they're computed only once at the bottom of the stack (that's critical
    4507             :      * for volatile functions).  As we climb up the stack, we'll add outputs
    4508             :      * for the WindowFuncs computed at each level.
    4509             :      */
    4510        2480 :     window_target = input_target;
    4511             : 
    4512        5110 :     foreach(l, activeWindows)
    4513             :     {
    4514        2630 :         WindowClause *wc = lfirst_node(WindowClause, l);
    4515             :         List       *window_pathkeys;
    4516             :         int         presorted_keys;
    4517             :         bool        is_sorted;
    4518             :         bool        topwindow;
    4519             : 
    4520        2630 :         window_pathkeys = make_pathkeys_for_window(root,
    4521             :                                                    wc,
    4522             :                                                    root->processed_tlist);
    4523             : 
    4524        2630 :         is_sorted = pathkeys_count_contained_in(window_pathkeys,
    4525             :                                                 path->pathkeys,
    4526             :                                                 &presorted_keys);
    4527             : 
    4528             :         /* Sort if necessary */
    4529        2630 :         if (!is_sorted)
    4530             :         {
    4531             :             /*
    4532             :              * No presorted keys or incremental sort disabled, just perform a
    4533             :              * complete sort.
    4534             :              */
    4535        2030 :             if (presorted_keys == 0 || !enable_incremental_sort)
    4536        1976 :                 path = (Path *) create_sort_path(root, window_rel,
    4537             :                                                  path,
    4538             :                                                  window_pathkeys,
    4539             :                                                  -1.0);
    4540             :             else
    4541             :             {
    4542             :                 /*
    4543             :                  * Since we have presorted keys and incremental sort is
    4544             :                  * enabled, just use incremental sort.
    4545             :                  */
    4546          54 :                 path = (Path *) create_incremental_sort_path(root,
    4547             :                                                              window_rel,
    4548             :                                                              path,
    4549             :                                                              window_pathkeys,
    4550             :                                                              presorted_keys,
    4551             :                                                              -1.0);
    4552             :             }
    4553             :         }
    4554             : 
    4555        2630 :         if (lnext(activeWindows, l))
    4556             :         {
    4557             :             /*
    4558             :              * Add the current WindowFuncs to the output target for this
    4559             :              * intermediate WindowAggPath.  We must copy window_target to
    4560             :              * avoid changing the previous path's target.
    4561             :              *
    4562             :              * Note: a WindowFunc adds nothing to the target's eval costs; but
    4563             :              * we do need to account for the increase in tlist width.
    4564             :              */
    4565         150 :             int64       tuple_width = window_target->width;
    4566             :             ListCell   *lc2;
    4567             : 
    4568         150 :             window_target = copy_pathtarget(window_target);
    4569         342 :             foreach(lc2, wflists->windowFuncs[wc->winref])
    4570             :             {
    4571         192 :                 WindowFunc *wfunc = lfirst_node(WindowFunc, lc2);
    4572             : 
    4573         192 :                 add_column_to_pathtarget(window_target, (Expr *) wfunc, 0);
    4574         192 :                 tuple_width += get_typavgwidth(wfunc->wintype, -1);
    4575             :             }
    4576         150 :             window_target->width = clamp_width_est(tuple_width);
    4577             :         }
    4578             :         else
    4579             :         {
    4580             :             /* Install the goal target in the topmost WindowAgg */
    4581        2480 :             window_target = output_target;
    4582             :         }
    4583             : 
    4584             :         /* mark the final item in the list as the top-level window */
    4585        2630 :         topwindow = foreach_current_index(l) == list_length(activeWindows) - 1;
    4586             : 
    4587             :         /*
    4588             :          * Accumulate all of the runConditions from each intermediate
    4589             :          * WindowClause.  The top-level WindowAgg must pass these as a qual so
    4590             :          * that it filters out unwanted tuples correctly.
    4591             :          */
    4592        2630 :         if (!topwindow)
    4593         150 :             topqual = list_concat(topqual, wc->runCondition);
    4594             : 
    4595             :         path = (Path *)
    4596        2630 :             create_windowagg_path(root, window_rel, path, window_target,
    4597        2630 :                                   wflists->windowFuncs[wc->winref],
    4598             :                                   wc, topwindow ? topqual : NIL, topwindow);
    4599             :     }
    4600             : 
    4601        2480 :     add_path(window_rel, path);
    4602        2480 : }
    4603             : 
    4604             : /*
    4605             :  * create_distinct_paths
    4606             :  *
    4607             :  * Build a new upperrel containing Paths for SELECT DISTINCT evaluation.
    4608             :  *
    4609             :  * input_rel: contains the source-data Paths
    4610             :  * target: the pathtarget for the result Paths to compute
    4611             :  *
    4612             :  * Note: input paths should already compute the desired pathtarget, since
    4613             :  * Sort/Unique won't project anything.
    4614             :  */
    4615             : static RelOptInfo *
    4616        2182 : create_distinct_paths(PlannerInfo *root, RelOptInfo *input_rel,
    4617             :                       PathTarget *target)
    4618             : {
    4619             :     RelOptInfo *distinct_rel;
    4620             : 
    4621             :     /* For now, do all work in the (DISTINCT, NULL) upperrel */
    4622        2182 :     distinct_rel = fetch_upper_rel(root, UPPERREL_DISTINCT, NULL);
    4623             : 
    4624             :     /*
    4625             :      * We don't compute anything at this level, so distinct_rel will be
    4626             :      * parallel-safe if the input rel is parallel-safe.  In particular, if
    4627             :      * there is a DISTINCT ON (...) clause, any path for the input_rel will
    4628             :      * output those expressions, and will not be parallel-safe unless those
    4629             :      * expressions are parallel-safe.
    4630             :      */
    4631        2182 :     distinct_rel->consider_parallel = input_rel->consider_parallel;
    4632             : 
    4633             :     /*
    4634             :      * If the input rel belongs to a single FDW, so does the distinct_rel.
    4635             :      */
    4636        2182 :     distinct_rel->serverid = input_rel->serverid;
    4637        2182 :     distinct_rel->userid = input_rel->userid;
    4638        2182 :     distinct_rel->useridiscurrent = input_rel->useridiscurrent;
    4639        2182 :     distinct_rel->fdwroutine = input_rel->fdwroutine;
    4640             : 
    4641             :     /* build distinct paths based on input_rel's pathlist */
    4642        2182 :     create_final_distinct_paths(root, input_rel, distinct_rel);
    4643             : 
    4644             :     /* now build distinct paths based on input_rel's partial_pathlist */
    4645        2182 :     create_partial_distinct_paths(root, input_rel, distinct_rel, target);
    4646             : 
    4647             :     /* Give a helpful error if we failed to create any paths */
    4648        2182 :     if (distinct_rel->pathlist == NIL)
    4649           0 :         ereport(ERROR,
    4650             :                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
    4651             :                  errmsg("could not implement DISTINCT"),
    4652             :                  errdetail("Some of the datatypes only support hashing, while others only support sorting.")));
    4653             : 
    4654             :     /*
    4655             :      * If there is an FDW that's responsible for all baserels of the query,
    4656             :      * let it consider adding ForeignPaths.
    4657             :      */
    4658        2182 :     if (distinct_rel->fdwroutine &&
    4659          16 :         distinct_rel->fdwroutine->GetForeignUpperPaths)
    4660          16 :         distinct_rel->fdwroutine->GetForeignUpperPaths(root,
    4661             :                                                        UPPERREL_DISTINCT,
    4662             :                                                        input_rel,
    4663             :                                                        distinct_rel,
    4664             :                                                        NULL);
    4665             : 
    4666             :     /* Let extensions possibly add some more paths */
    4667        2182 :     if (create_upper_paths_hook)
    4668           0 :         (*create_upper_paths_hook) (root, UPPERREL_DISTINCT, input_rel,
    4669             :                                     distinct_rel, NULL);
    4670             : 
    4671             :     /* Now choose the best path(s) */
    4672        2182 :     set_cheapest(distinct_rel);
    4673             : 
    4674        2182 :     return distinct_rel;
    4675             : }
    4676             : 
    4677             : /*
    4678             :  * create_partial_distinct_paths
    4679             :  *
    4680             :  * Process 'input_rel' partial paths and add unique/aggregate paths to the
    4681             :  * UPPERREL_PARTIAL_DISTINCT rel.  For paths created, add Gather/GatherMerge
    4682             :  * paths on top and add a final unique/aggregate path to remove any duplicate
    4683             :  * produced from combining rows from parallel workers.
    4684             :  */
    4685             : static void
    4686        2182 : create_partial_distinct_paths(PlannerInfo *root, RelOptInfo *input_rel,
    4687             :                               RelOptInfo *final_distinct_rel,
    4688             :                               PathTarget *target)
    4689             : {
    4690             :     RelOptInfo *partial_distinct_rel;
    4691             :     Query      *parse;
    4692             :     List       *distinctExprs;
    4693             :     double      numDistinctRows;
    4694             :     Path       *cheapest_partial_path;
    4695             :     ListCell   *lc;
    4696             : 
    4697             :     /* nothing to do when there are no partial paths in the input rel */
    4698        2182 :     if (!input_rel->consider_parallel || input_rel->partial_pathlist == NIL)
    4699        2086 :         return;
    4700             : 
    4701          96 :     parse = root->parse;
    4702             : 
    4703             :     /* can't do parallel DISTINCT ON */
    4704          96 :     if (parse->hasDistinctOn)
    4705           0 :         return;
    4706             : 
    4707          96 :     partial_distinct_rel = fetch_upper_rel(root, UPPERREL_PARTIAL_DISTINCT,
    4708             :                                            NULL);
    4709          96 :     partial_distinct_rel->reltarget = target;
    4710          96 :     partial_distinct_rel->consider_parallel = input_rel->consider_parallel;
    4711             : 
    4712             :     /*
    4713             :      * If input_rel belongs to a single FDW, so does the partial_distinct_rel.
    4714             :      */
    4715          96 :     partial_distinct_rel->serverid = input_rel->serverid;
    4716          96 :     partial_distinct_rel->userid = input_rel->userid;
    4717          96 :     partial_distinct_rel->useridiscurrent = input_rel->useridiscurrent;
    4718          96 :     partial_distinct_rel->fdwroutine = input_rel->fdwroutine;
    4719             : 
    4720          96 :     cheapest_partial_path = linitial(input_rel->partial_pathlist);
    4721             : 
    4722          96 :     distinctExprs = get_sortgrouplist_exprs(root->processed_distinctClause,
    4723             :                                             parse->targetList);
    4724             : 
    4725             :     /* estimate how many distinct rows we'll get from each worker */
    4726          96 :     numDistinctRows = estimate_num_groups(root, distinctExprs,
    4727             :                                           cheapest_partial_path->rows,
    4728             :                                           NULL, NULL);
    4729             : 
    4730             :     /*
    4731             :      * Try sorting the cheapest path and incrementally sorting any paths with
    4732             :      * presorted keys and put a unique paths atop of those.
    4733             :      */
    4734          96 :     if (grouping_is_sortable(root->processed_distinctClause))
    4735             :     {
    4736         198 :         foreach(lc, input_rel->partial_pathlist)
    4737             :         {
    4738         102 :             Path       *input_path = (Path *) lfirst(lc);
    4739             :             Path       *sorted_path;
    4740             :             bool        is_sorted;
    4741             :             int         presorted_keys;
    4742             : 
    4743         102 :             is_sorted = pathkeys_count_contained_in(root->distinct_pathkeys,
    4744             :                                                     input_path->pathkeys,
    4745             :                                                     &presorted_keys);
    4746             : 
    4747         102 :             if (is_sorted)
    4748           6 :                 sorted_path = input_path;
    4749             :             else
    4750             :             {
    4751             :                 /*
    4752             :                  * Try at least sorting the cheapest path and also try
    4753             :                  * incrementally sorting any path which is partially sorted
    4754             :                  * already (no need to deal with paths which have presorted
    4755             :                  * keys when incremental sort is disabled unless it's the
    4756             :                  * cheapest partial path).
    4757             :                  */
    4758          96 :                 if (input_path != cheapest_partial_path &&
    4759           6 :                     (presorted_keys == 0 || !enable_incremental_sort))
    4760           0 :                     continue;
    4761             : 
    4762             :                 /*
    4763             :                  * We've no need to consider both a sort and incremental sort.
    4764             :                  * We'll just do a sort if there are no presorted keys and an
    4765             :                  * incremental sort when there are presorted keys.
    4766             :                  */
    4767          96 :                 if (presorted_keys == 0 || !enable_incremental_sort)
    4768          90 :                     sorted_path = (Path *) create_sort_path(root,
    4769             :                                                             partial_distinct_rel,
    4770             :                                                             input_path,
    4771             :                                                             root->distinct_pathkeys,
    4772             :                                                             -1.0);
    4773             :                 else
    4774           6 :                     sorted_path = (Path *) create_incremental_sort_path(root,
    4775             :                                                                         partial_distinct_rel,
    4776             :                                                                         input_path,
    4777             :                                                                         root->distinct_pathkeys,
    4778             :                                                                         presorted_keys,
    4779             :                                                                         -1.0);
    4780             :             }
    4781             : 
    4782             :             /*
    4783             :              * An empty distinct_pathkeys means all tuples have the same value
    4784             :              * for the DISTINCT clause.  See create_final_distinct_paths()
    4785             :              */
    4786         102 :             if (root->distinct_pathkeys == NIL)
    4787             :             {
    4788             :                 Node       *limitCount;
    4789             : 
    4790           6 :                 limitCount = (Node *) makeConst(INT8OID, -1, InvalidOid,
    4791             :                                                 sizeof(int64),
    4792             :                                                 Int64GetDatum(1), false,
    4793             :                                                 FLOAT8PASSBYVAL);
    4794             : 
    4795             :                 /*
    4796             :                  * Apply a LimitPath onto the partial path to restrict the
    4797             :                  * tuples from each worker to 1.  create_final_distinct_paths
    4798             :                  * will need to apply an additional LimitPath to restrict this
    4799             :                  * to a single row after the Gather node.  If the query
    4800             :                  * already has a LIMIT clause, then we could end up with three
    4801             :                  * Limit nodes in the final plan.  Consolidating the top two
    4802             :                  * of these could be done, but does not seem worth troubling
    4803             :                  * over.
    4804             :                  */
    4805           6 :                 add_partial_path(partial_distinct_rel, (Path *)
    4806           6 :                                  create_limit_path(root, partial_distinct_rel,
    4807             :                                                    sorted_path,
    4808             :                                                    NULL,
    4809             :                                                    limitCount,
    4810             :                                                    LIMIT_OPTION_COUNT,
    4811             :                                                    0, 1));
    4812             :             }
    4813             :             else
    4814             :             {
    4815          96 :                 add_partial_path(partial_distinct_rel, (Path *)
    4816          96 :                                  create_upper_unique_path(root, partial_distinct_rel,
    4817             :                                                           sorted_path,
    4818          96 :                                                           list_length(root->distinct_pathkeys),
    4819             :                                                           numDistinctRows));
    4820             :             }
    4821             :         }
    4822             :     }
    4823             : 
    4824             :     /*
    4825             :      * Now try hash aggregate paths, if enabled and hashing is possible. Since
    4826             :      * we're not on the hook to ensure we do our best to create at least one
    4827             :      * path here, we treat enable_hashagg as a hard off-switch rather than the
    4828             :      * slightly softer variant in create_final_distinct_paths.
    4829             :      */
    4830          96 :     if (enable_hashagg && grouping_is_hashable(root->processed_distinctClause))
    4831             :     {
    4832          78 :         add_partial_path(partial_distinct_rel, (Path *)
    4833          78 :                          create_agg_path(root,
    4834             :                                          partial_distinct_rel,
    4835             :                                          cheapest_partial_path,
    4836             :                                          cheapest_partial_path->pathtarget,
    4837             :                                          AGG_HASHED,
    4838             :                                          AGGSPLIT_SIMPLE,
    4839             :                                          root->processed_distinctClause,
    4840             :                                          NIL,
    4841             :                                          NULL,
    4842             :                                          numDistinctRows));
    4843             :     }
    4844             : 
    4845             :     /*
    4846             :      * If there is an FDW that's responsible for all baserels of the query,
    4847             :      * let it consider adding ForeignPaths.
    4848             :      */
    4849          96 :     if (partial_distinct_rel->fdwroutine &&
    4850           0 :         partial_distinct_rel->fdwroutine->GetForeignUpperPaths)
    4851           0 :         partial_distinct_rel->fdwroutine->GetForeignUpperPaths(root,
    4852             :                                                                UPPERREL_PARTIAL_DISTINCT,
    4853             :                                                                input_rel,
    4854             :                                                                partial_distinct_rel,
    4855             :                                                                NULL);
    4856             : 
    4857             :     /* Let extensions possibly add some more partial paths */
    4858          96 :     if (create_upper_paths_hook)
    4859           0 :         (*create_upper_paths_hook) (root, UPPERREL_PARTIAL_DISTINCT,
    4860             :                                     input_rel, partial_distinct_rel, NULL);
    4861             : 
    4862          96 :     if (partial_distinct_rel->partial_pathlist != NIL)
    4863             :     {
    4864          96 :         generate_useful_gather_paths(root, partial_distinct_rel, true);
    4865          96 :         set_cheapest(partial_distinct_rel);
    4866             : 
    4867             :         /*
    4868             :          * Finally, create paths to distinctify the final result.  This step
    4869             :          * is needed to remove any duplicates due to combining rows from
    4870             :          * parallel workers.
    4871             :          */
    4872          96 :         create_final_distinct_paths(root, partial_distinct_rel,
    4873             :                                     final_distinct_rel);
    4874             :     }
    4875             : }
    4876             : 
    4877             : /*
    4878             :  * create_final_distinct_paths
    4879             :  *      Create distinct paths in 'distinct_rel' based on 'input_rel' pathlist
    4880             :  *
    4881             :  * input_rel: contains the source-data paths
    4882             :  * distinct_rel: destination relation for storing created paths
    4883             :  */
    4884             : static RelOptInfo *
    4885        2278 : create_final_distinct_paths(PlannerInfo *root, RelOptInfo *input_rel,
    4886             :                             RelOptInfo *distinct_rel)
    4887             : {
    4888        2278 :     Query      *parse = root->parse;
    4889        2278 :     Path       *cheapest_input_path = input_rel->cheapest_total_path;
    4890             :     double      numDistinctRows;
    4891             :     bool        allow_hash;
    4892             : 
    4893             :     /* Estimate number of distinct rows there will be */
    4894        2278 :     if (parse->groupClause || parse->groupingSets || parse->hasAggs ||
    4895        2240 :         root->hasHavingQual)
    4896             :     {
    4897             :         /*
    4898             :          * If there was grouping or aggregation, use the number of input rows
    4899             :          * as the estimated number of DISTINCT rows (ie, assume the input is
    4900             :          * already mostly unique).
    4901             :          */
    4902          38 :         numDistinctRows = cheapest_input_path->rows;
    4903             :     }
    4904             :     else
    4905             :     {
    4906             :         /*
    4907             :          * Otherwise, the UNIQUE filter has effects comparable to GROUP BY.
    4908             :          */
    4909             :         List       *distinctExprs;
    4910             : 
    4911        2240 :         distinctExprs = get_sortgrouplist_exprs(root->processed_distinctClause,
    4912             :                                                 parse->targetList);
    4913        2240 :         numDistinctRows = estimate_num_groups(root, distinctExprs,
    4914             :                                               cheapest_input_path->rows,
    4915             :                                               NULL, NULL);
    4916             :     }
    4917             : 
    4918             :     /*
    4919             :      * Consider sort-based implementations of DISTINCT, if possible.
    4920             :      */
    4921        2278 :     if (grouping_is_sortable(root->processed_distinctClause))
    4922             :     {
    4923             :         /*
    4924             :          * Firstly, if we have any adequately-presorted paths, just stick a
    4925             :          * Unique node on those.  We also, consider doing an explicit sort of
    4926             :          * the cheapest input path and Unique'ing that.  If any paths have
    4927             :          * presorted keys then we'll create an incremental sort atop of those
    4928             :          * before adding a unique node on the top.
    4929             :          *
    4930             :          * When we have DISTINCT ON, we must sort by the more rigorous of
    4931             :          * DISTINCT and ORDER BY, else it won't have the desired behavior.
    4932             :          * Also, if we do have to do an explicit sort, we might as well use
    4933             :          * the more rigorous ordering to avoid a second sort later.  (Note
    4934             :          * that the parser will have ensured that one clause is a prefix of
    4935             :          * the other.)
    4936             :          */
    4937             :         List       *needed_pathkeys;
    4938             :         ListCell   *lc;
    4939        2272 :         double      limittuples = root->distinct_pathkeys == NIL ? 1.0 : -1.0;
    4940             : 
    4941        2440 :         if (parse->hasDistinctOn &&
    4942         168 :             list_length(root->distinct_pathkeys) <
    4943         168 :             list_length(root->sort_pathkeys))
    4944          42 :             needed_pathkeys = root->sort_pathkeys;
    4945             :         else
    4946        2230 :             needed_pathkeys = root->distinct_pathkeys;
    4947             : 
    4948        5436 :         foreach(lc, input_rel->pathlist)
    4949             :         {
    4950        3164 :             Path       *input_path = (Path *) lfirst(lc);
    4951             :             Path       *sorted_path;
    4952             :             bool        is_sorted;
    4953             :             int         presorted_keys;
    4954             : 
    4955        3164 :             is_sorted = pathkeys_count_contained_in(needed_pathkeys,
    4956             :                                                     input_path->pathkeys,
    4957             :                                                     &presorted_keys);
    4958             : 
    4959        3164 :             if (is_sorted)
    4960         644 :                 sorted_path = input_path;
    4961             :             else
    4962             :             {
    4963             :                 /*
    4964             :                  * Try at least sorting the cheapest path and also try
    4965             :                  * incrementally sorting any path which is partially sorted
    4966             :                  * already (no need to deal with paths which have presorted
    4967             :                  * keys when incremental sort is disabled unless it's the
    4968             :                  * cheapest input path).
    4969             :                  */
    4970        2520 :                 if (input_path != cheapest_input_path &&
    4971         412 :                     (presorted_keys == 0 || !enable_incremental_sort))
    4972          82 :                     continue;
    4973             : 
    4974             :                 /*
    4975             :                  * We've no need to consider both a sort and incremental sort.
    4976             :                  * We'll just do a sort if there are no presorted keys and an
    4977             :                  * incremental sort when there are presorted keys.
    4978             :                  */
    4979        2438 :                 if (presorted_keys == 0 || !enable_incremental_sort)
    4980        2090 :                     sorted_path = (Path *) create_sort_path(root,
    4981             :                                                             distinct_rel,
    4982             :                                                             input_path,
    4983             :                                                             needed_pathkeys,
    4984             :                                                             limittuples);
    4985             :                 else
    4986         348 :                     sorted_path = (Path *) create_incremental_sort_path(root,
    4987             :                                                                         distinct_rel,
    4988             :                                                                         input_path,
    4989             :                                                                         needed_pathkeys,
    4990             :                                                                         presorted_keys,
    4991             :                                                                         limittuples);
    4992             :             }
    4993             : 
    4994             :             /*
    4995             :              * distinct_pathkeys may have become empty if all of the pathkeys
    4996             :              * were determined to be redundant.  If all of the pathkeys are
    4997             :              * redundant then each DISTINCT target must only allow a single
    4998             :              * value, therefore all resulting tuples must be identical (or at
    4999             :              * least indistinguishable by an equality check).  We can uniquify
    5000             :              * these tuples simply by just taking the first tuple.  All we do
    5001             :              * here is add a path to do "LIMIT 1" atop of 'sorted_path'.  When
    5002             :              * doing a DISTINCT ON we may still have a non-NIL sort_pathkeys
    5003             :              * list, so we must still only do this with paths which are
    5004             :              * correctly sorted by sort_pathkeys.
    5005             :              */
    5006        3082 :             if (root->distinct_pathkeys == NIL)
    5007             :             {
    5008             :                 Node       *limitCount;
    5009             : 
    5010          98 :                 limitCount = (Node *) makeConst(INT8OID, -1, InvalidOid,
    5011             :                                                 sizeof(int64),
    5012             :                                                 Int64GetDatum(1), false,
    5013             :                                                 FLOAT8PASSBYVAL);
    5014             : 
    5015             :                 /*
    5016             :                  * If the query already has a LIMIT clause, then we could end
    5017             :                  * up with a duplicate LimitPath in the final plan. That does
    5018             :                  * not seem worth troubling over too much.
    5019             :                  */
    5020          98 :                 add_path(distinct_rel, (Path *)
    5021          98 :                          create_limit_path(root, distinct_rel, sorted_path,
    5022             :                                            NULL, limitCount,
    5023             :                                            LIMIT_OPTION_COUNT, 0, 1));
    5024             :             }
    5025             :             else
    5026             :             {
    5027        2984 :                 add_path(distinct_rel, (Path *)
    5028        2984 :                          create_upper_unique_path(root, distinct_rel,
    5029             :                                                   sorted_path,
    5030        2984 :                                                   list_length(root->distinct_pathkeys),
    5031             :                                                   numDistinctRows));
    5032             :             }
    5033             :         }
    5034             :     }
    5035             : 
    5036             :     /*
    5037             :      * Consider hash-based implementations of DISTINCT, if possible.
    5038             :      *
    5039             :      * If we were not able to make any other types of path, we *must* hash or
    5040             :      * die trying.  If we do have other choices, there are two things that
    5041             :      * should prevent selection of hashing: if the query uses DISTINCT ON
    5042             :      * (because it won't really have the expected behavior if we hash), or if
    5043             :      * enable_hashagg is off.
    5044             :      *
    5045             :      * Note: grouping_is_hashable() is much more expensive to check than the
    5046             :      * other gating conditions, so we want to do it last.
    5047             :      */
    5048        2278 :     if (distinct_rel->pathlist == NIL)
    5049           6 :         allow_hash = true;      /* we have no alternatives */
    5050        2272 :     else if (parse->hasDistinctOn || !enable_hashagg)
    5051         258 :         allow_hash = false;     /* policy-based decision not to hash */
    5052             :     else
    5053        2014 :         allow_hash = true;      /* default */
    5054             : 
    5055        2278 :     if (allow_hash && grouping_is_hashable(root->processed_distinctClause))
    5056             :     {
    5057             :         /* Generate hashed aggregate path --- no sort needed */
    5058        2020 :         add_path(distinct_rel, (Path *)
    5059        2020 :                  create_agg_path(root,
    5060             :                                  distinct_rel,
    5061             :                                  cheapest_input_path,
    5062             :                                  cheapest_input_path->pathtarget,
    5063             :                                  AGG_HASHED,
    5064             :                                  AGGSPLIT_SIMPLE,
    5065             :                                  root->processed_distinctClause,
    5066             :                                  NIL,
    5067             :                                  NULL,
    5068             :                                  numDistinctRows));
    5069             :     }
    5070             : 
    5071        2278 :     return distinct_rel;
    5072             : }
    5073             : 
    5074             : /*
    5075             :  * create_ordered_paths
    5076             :  *
    5077             :  * Build a new upperrel containing Paths for ORDER BY evaluation.
    5078             :  *
    5079             :  * All paths in the result must satisfy the ORDER BY ordering.
    5080             :  * The only new paths we need consider are an explicit full sort
    5081             :  * and incremental sort on the cheapest-total existing path.
    5082             :  *
    5083             :  * input_rel: contains the source-data Paths
    5084             :  * target: the output tlist the result Paths must emit
    5085             :  * limit_tuples: estimated bound on the number of output tuples,
    5086             :  *      or -1 if no LIMIT or couldn't estimate
    5087             :  *
    5088             :  * XXX This only looks at sort_pathkeys. I wonder if it needs to look at the
    5089             :  * other pathkeys (grouping, ...) like generate_useful_gather_paths.
    5090             :  */
    5091             : static RelOptInfo *
    5092       56862 : create_ordered_paths(PlannerInfo *root,
    5093             :                      RelOptInfo *input_rel,
    5094             :                      PathTarget *target,
    5095             :                      bool target_parallel_safe,
    5096             :                      double limit_tuples)
    5097             : {
    5098       56862 :     Path       *cheapest_input_path = input_rel->cheapest_total_path;
    5099             :     RelOptInfo *ordered_rel;
    5100             :     ListCell   *lc;
    5101             : 
    5102             :     /* For now, do all work in the (ORDERED, NULL) upperrel */
    5103       56862 :     ordered_rel = fetch_upper_rel(root, UPPERREL_ORDERED, NULL);
    5104             : 
    5105             :     /*
    5106             :      * If the input relation is not parallel-safe, then the ordered relation
    5107             :      * can't be parallel-safe, either.  Otherwise, it's parallel-safe if the
    5108             :      * target list is parallel-safe.
    5109             :      */
    5110       56862 :     if (input_rel->consider_parallel && target_parallel_safe)
    5111       37534 :         ordered_rel->consider_parallel = true;
    5112             : 
    5113             :     /*
    5114             :      * If the input rel belongs to a single FDW, so does the ordered_rel.
    5115             :      */
    5116       56862 :     ordered_rel->serverid = input_rel->serverid;
    5117       56862 :     ordered_rel->userid = input_rel->userid;
    5118       56862 :     ordered_rel->useridiscurrent = input_rel->useridiscurrent;
    5119       56862 :     ordered_rel->fdwroutine = input_rel->fdwroutine;
    5120             : 
    5121      143136 :     foreach(lc, input_rel->pathlist)
    5122             :     {
    5123       86274 :         Path       *input_path = (Path *) lfirst(lc);
    5124             :         Path       *sorted_path;
    5125             :         bool        is_sorted;
    5126             :         int         presorted_keys;
    5127             : 
    5128       86274 :         is_sorted = pathkeys_count_contained_in(root->sort_pathkeys,
    5129             :                                                 input_path->pathkeys, &presorted_keys);
    5130             : 
    5131       86274 :         if (is_sorted)
    5132       31884 :             sorted_path = input_path;
    5133             :         else
    5134             :         {
    5135             :             /*
    5136             :              * Try at least sorting the cheapest path and also try
    5137             :              * incrementally sorting any path which is partially sorted
    5138             :              * already (no need to deal with paths which have presorted keys
    5139             :              * when incremental sort is disabled unless it's the cheapest
    5140             :              * input path).
    5141             :              */
    5142       54390 :             if (input_path != cheapest_input_path &&
    5143        5178 :                 (presorted_keys == 0 || !enable_incremental_sort))
    5144        1622 :                 continue;
    5145             : 
    5146             :             /*
    5147             :              * We've no need to consider both a sort and incremental sort.
    5148             :              * We'll just do a sort if there are no presorted keys and an
    5149             :              * incremental sort when there are presorted keys.
    5150             :              */
    5151       52768 :             if (presorted_keys == 0 || !enable_incremental_sort)
    5152       48820 :                 sorted_path = (Path *) create_sort_path(root,
    5153             :                                                         ordered_rel,
    5154             :                                                         input_path,
    5155             :                                                         root->sort_pathkeys,
    5156             :                                                         limit_tuples);
    5157             :             else
    5158        3948 :                 sorted_path = (Path *) create_incremental_sort_path(root,
    5159             :                                                                     ordered_rel,
    5160             :                                                                     input_path,
    5161             :                                                                     root->sort_pathkeys,
    5162             :                                                                     presorted_keys,
    5163             :                                                                     limit_tuples);
    5164             :         }
    5165             : 
    5166             :         /* Add projection step if needed */
    5167       84652 :         if (sorted_path->pathtarget != target)
    5168       17784 :             sorted_path = apply_projection_to_path(root, ordered_rel,
    5169             :                                                    sorted_path, target);
    5170             : 
    5171       84652 :         add_path(ordered_rel, sorted_path);
    5172             :     }
    5173             : 
    5174             :     /*
    5175             :      * generate_gather_paths() will have already generated a simple Gather
    5176             :      * path for the best parallel path, if any, and the loop above will have
    5177             :      * considered sorting it.  Similarly, generate_gather_paths() will also
    5178             :      * have generated order-preserving Gather Merge plans which can be used
    5179             :      * without sorting if they happen to match the sort_pathkeys, and the loop
    5180             :      * above will have handled those as well.  However, there's one more
    5181             :      * possibility: it may make sense to sort the cheapest partial path or
    5182             :      * incrementally sort any partial path that is partially sorted according
    5183             :      * to the required output order and then use Gather Merge.
    5184             :      */
    5185       56862 :     if (ordered_rel->consider_parallel && root->sort_pathkeys != NIL &&
    5186       37396 :         input_rel->partial_pathlist != NIL)
    5187             :     {
    5188             :         Path       *cheapest_partial_path;
    5189             : 
    5190        2110 :         cheapest_partial_path = linitial(input_rel->partial_pathlist);
    5191             : 
    5192        4444 :         foreach(lc, input_rel->partial_pathlist)
    5193             :         {
    5194        2334 :             Path       *input_path = (Path *) lfirst(lc);
    5195             :             Path       *sorted_path;
    5196             :             bool        is_sorted;
    5197             :             int         presorted_keys;
    5198             :             double      total_groups;
    5199             : 
    5200        2334 :             is_sorted = pathkeys_count_contained_in(root->sort_pathkeys,
    5201             :                                                     input_path->pathkeys,
    5202             :                                                     &presorted_keys);
    5203             : 
    5204        2334 :             if (is_sorted)
    5205         194 :                 continue;
    5206             : 
    5207             :             /*
    5208             :              * Try at least sorting the cheapest path and also try
    5209             :              * incrementally sorting any path which is partially sorted
    5210             :              * already (no need to deal with paths which have presorted keys
    5211             :              * when incremental sort is disabled unless it's the cheapest
    5212             :              * partial path).
    5213             :              */
    5214        2140 :             if (input_path != cheapest_partial_path &&
    5215          42 :                 (presorted_keys == 0 || !enable_incremental_sort))
    5216           0 :                 continue;
    5217             : 
    5218             :             /*
    5219             :              * We've no need to consider both a sort and incremental sort.
    5220             :              * We'll just do a sort if there are no presorted keys and an
    5221             :              * incremental sort when there are presorted keys.
    5222             :              */
    5223        2140 :             if (presorted_keys == 0 || !enable_incremental_sort)
    5224        2080 :                 sorted_path = (Path *) create_sort_path(root,
    5225             :                                                         ordered_rel,
    5226             :                                                         input_path,
    5227             :                                                         root->sort_pathkeys,
    5228             :                                                         limit_tuples);
    5229             :             else
    5230          60 :                 sorted_path = (Path *) create_incremental_sort_path(root,
    5231             :                                                                     ordered_rel,
    5232             :                                                                     input_path,
    5233             :                                                                     root->sort_pathkeys,
    5234             :                                                                     presorted_keys,
    5235             :                                                                     limit_tuples);
    5236        2140 :             total_groups = input_path->rows *
    5237        2140 :                 input_path->parallel_workers;
    5238             :             sorted_path = (Path *)
    5239        2140 :                 create_gather_merge_path(root, ordered_rel,
    5240             :                                          sorted_path,
    5241             :                                          sorted_path->pathtarget,
    5242             :                                          root->sort_pathkeys, NULL,
    5243             :                                          &total_groups);
    5244             : 
    5245             :             /* Add projection step if needed */
    5246        2140 :             if (sorted_path->pathtarget != target)
    5247         438 :                 sorted_path = apply_projection_to_path(root, ordered_rel,
    5248             :                                                        sorted_path, target);
    5249             : 
    5250        2140 :             add_path(ordered_rel, sorted_path);
    5251             :         }
    5252             :     }
    5253             : 
    5254             :     /*
    5255             :      * If there is an FDW that's responsible for all baserels of the query,
    5256             :      * let it consider adding ForeignPaths.
    5257             :      */
    5258       56862 :     if (ordered_rel->fdwroutine &&
    5259         376 :         ordered_rel->fdwroutine->GetForeignUpperPaths)
    5260         362 :         ordered_rel->fdwroutine->GetForeignUpperPaths(root, UPPERREL_ORDERED,
    5261             :                                                       input_rel, ordered_rel,
    5262             :                                                       NULL);
    5263             : 
    5264             :     /* Let extensions possibly add some more paths */
    5265       56862 :     if (create_upper_paths_hook)
    5266           0 :         (*create_upper_paths_hook) (root, UPPERREL_ORDERED,
    5267             :                                     input_rel, ordered_rel, NULL);
    5268             : 
    5269             :     /*
    5270             :      * No need to bother with set_cheapest here; grouping_planner does not
    5271             :      * need us to do it.
    5272             :      */
    5273             :     Assert(ordered_rel->pathlist != NIL);
    5274             : 
    5275       56862 :     return ordered_rel;
    5276             : }
    5277             : 
    5278             : 
    5279             : /*
    5280             :  * make_group_input_target
    5281             :  *    Generate appropriate PathTarget for initial input to grouping nodes.
    5282             :  *
    5283             :  * If there is grouping or aggregation, the scan/join subplan cannot emit
    5284             :  * the query's final targetlist; for example, it certainly can't emit any
    5285             :  * aggregate function calls.  This routine generates the correct target
    5286             :  * for the scan/join subplan.
    5287             :  *
    5288             :  * The query target list passed from the parser already contains entries
    5289             :  * for all ORDER BY and GROUP BY expressions, but it will not have entries
    5290             :  * for variables used only in HAVING clauses; so we need to add those
    5291             :  * variables to the subplan target list.  Also, we flatten all expressions
    5292             :  * except GROUP BY items into their component variables; other expressions
    5293             :  * will be computed by the upper plan nodes rather than by the subplan.
    5294             :  * For example, given a query like
    5295             :  *      SELECT a+b,SUM(c+d) FROM table GROUP BY a+b;
    5296             :  * we want to pass this targetlist to the subplan:
    5297             :  *      a+b,c,d
    5298             :  * where the a+b target will be used by the Sort/Group steps, and the
    5299             :  * other targets will be used for computing the final results.
    5300             :  *
    5301             :  * 'final_target' is the query's final target list (in PathTarget form)
    5302             :  *
    5303             :  * The result is the PathTarget to be computed by the Paths returned from
    5304             :  * query_planner().
    5305             :  */
    5306             : static PathTarget *
    5307       34026 : make_group_input_target(PlannerInfo *root, PathTarget *final_target)
    5308             : {
    5309       34026 :     Query      *parse = root->parse;
    5310             :     PathTarget *input_target;
    5311             :     List       *non_group_cols;
    5312             :     List       *non_group_vars;
    5313             :     int         i;
    5314             :     ListCell   *lc;
    5315             : 
    5316             :     /*
    5317             :      * We must build a target containing all grouping columns, plus any other
    5318             :      * Vars mentioned in the query's targetlist and HAVING qual.
    5319             :      */
    5320       34026 :     input_target = create_empty_pathtarget();
    5321       34026 :     non_group_cols = NIL;
    5322             : 
    5323       34026 :     i = 0;
    5324       82948 :     foreach(lc, final_target->exprs)
    5325             :     {
    5326       48922 :         Expr       *expr = (Expr *) lfirst(lc);
    5327       48922 :         Index       sgref = get_pathtarget_sortgroupref(final_target, i);
    5328             : 
    5329       56894 :         if (sgref && root->processed_groupClause &&
    5330        7972 :             get_sortgroupref_clause_noerr(sgref,
    5331             :                                           root->processed_groupClause) != NULL)
    5332             :         {
    5333             :             /*
    5334             :              * It's a grouping column, so add it to the input target as-is.
    5335             :              */
    5336        6416 :             add_column_to_pathtarget(input_target, expr, sgref);
    5337             :         }
    5338             :         else
    5339             :         {
    5340             :             /*
    5341             :              * Non-grouping column, so just remember the expression for later
    5342             :              * call to pull_var_clause.
    5343             :              */
    5344       42506 :             non_group_cols = lappend(non_group_cols, expr);
    5345             :         }
    5346             : 
    5347       48922 :         i++;
    5348             :     }
    5349             : 
    5350             :     /*
    5351             :      * If there's a HAVING clause, we'll need the Vars it uses, too.
    5352             :      */
    5353       34026 :     if (parse->havingQual)
    5354         988 :         non_group_cols = lappend(non_group_cols, parse->havingQual);
    5355             : 
    5356             :     /*
    5357             :      * Pull out all the Vars mentioned in non-group cols (plus HAVING), and
    5358             :      * add them to the input target if not already present.  (A Var used
    5359             :      * directly as a GROUP BY item will be present already.)  Note this
    5360             :      * includes Vars used in resjunk items, so we are covering the needs of
    5361             :      * ORDER BY and window specifications.  Vars used within Aggrefs and
    5362             :      * WindowFuncs will be pulled out here, too.
    5363             :      */
    5364       34026 :     non_group_vars = pull_var_clause((Node *) non_group_cols,
    5365             :                                      PVC_RECURSE_AGGREGATES |
    5366             :                                      PVC_RECURSE_WINDOWFUNCS |
    5367             :                                      PVC_INCLUDE_PLACEHOLDERS);
    5368       34026 :     add_new_columns_to_pathtarget(input_target, non_group_vars);
    5369             : 
    5370             :     /* clean up cruft */
    5371       34026 :     list_free(non_group_vars);
    5372       34026 :     list_free(non_group_cols);
    5373             : 
    5374             :     /* XXX this causes some redundant cost calculation ... */
    5375       34026 :     return set_pathtarget_cost_width(root, input_target);
    5376             : }
    5377             : 
    5378             : /*
    5379             :  * make_partial_grouping_target
    5380             :  *    Generate appropriate PathTarget for output of partial aggregate
    5381             :  *    (or partial grouping, if there are no aggregates) nodes.
    5382             :  *
    5383             :  * A partial aggregation node needs to emit all the same aggregates that
    5384             :  * a regular aggregation node would, plus any aggregates used in HAVING;
    5385             :  * except that the Aggref nodes should be marked as partial aggregates.
    5386             :  *
    5387             :  * In addition, we'd better emit any Vars and PlaceHolderVars that are
    5388             :  * used outside of Aggrefs in the aggregation tlist and HAVING.  (Presumably,
    5389             :  * these would be Vars that are grouped by or used in grouping expressions.)
    5390             :  *
    5391             :  * grouping_target is the tlist to be emitted by the topmost aggregation step.
    5392             :  * havingQual represents the HAVING clause.
    5393             :  */
    5394             : static PathTarget *
    5395        2148 : make_partial_grouping_target(PlannerInfo *root,
    5396             :                              PathTarget *grouping_target,
    5397             :                              Node *havingQual)
    5398             : {
    5399             :     PathTarget *partial_target;
    5400             :     List       *non_group_cols;
    5401             :     List       *non_group_exprs;
    5402             :     int         i;
    5403             :     ListCell   *lc;
    5404             : 
    5405        2148 :     partial_target = create_empty_pathtarget();
    5406        2148 :     non_group_cols = NIL;
    5407             : 
    5408        2148 :     i = 0;
    5409        7642 :     foreach(lc, grouping_target->exprs)
    5410             :     {
    5411        5494 :         Expr       *expr = (Expr *) lfirst(lc);
    5412        5494 :         Index       sgref = get_pathtarget_sortgroupref(grouping_target, i);
    5413             : 
    5414        9236 :         if (sgref && root->processed_groupClause &&
    5415        3742 :             get_sortgroupref_clause_noerr(sgref,
    5416             :                                           root->processed_groupClause) != NULL)
    5417             :         {
    5418             :             /*
    5419             :              * It's a grouping column, so add it to the partial_target as-is.
    5420             :              * (This allows the upper agg step to repeat the grouping calcs.)
    5421             :              */
    5422        1864 :             add_column_to_pathtarget(partial_target, expr, sgref);
    5423             :         }
    5424             :         else
    5425             :         {
    5426             :             /*
    5427             :              * Non-grouping column, so just remember the expression for later
    5428             :              * call to pull_var_clause.
    5429             :              */
    5430        3630 :             non_group_cols = lappend(non_group_cols, expr);
    5431             :         }
    5432             : 
    5433        5494 :         i++;
    5434             :     }
    5435             : 
    5436             :     /*
    5437             :      * If there's a HAVING clause, we'll need the Vars/Aggrefs it uses, too.
    5438             :      */
    5439        2148 :     if (havingQual)
    5440         824 :         non_group_cols = lappend(non_group_cols, havingQual);
    5441             : 
    5442             :     /*
    5443             :      * Pull out all the Vars, PlaceHolderVars, and Aggrefs mentioned in
    5444             :      * non-group cols (plus HAVING), and add them to the partial_target if not
    5445             :      * already present.  (An expression used directly as a GROUP BY item will
    5446             :      * be present already.)  Note this includes Vars used in resjunk items, so
    5447             :      * we are covering the needs of ORDER BY and window specifications.
    5448             :      */
    5449        2148 :     non_group_exprs = pull_var_clause((Node *) non_group_cols,
    5450             :                                       PVC_INCLUDE_AGGREGATES |
    5451             :                                       PVC_RECURSE_WINDOWFUNCS |
    5452             :                                       PVC_INCLUDE_PLACEHOLDERS);
    5453             : 
    5454        2148 :     add_new_columns_to_pathtarget(partial_target, non_group_exprs);
    5455             : 
    5456             :     /*
    5457             :      * Adjust Aggrefs to put them in partial mode.  At this point all Aggrefs
    5458             :      * are at the top level of the target list, so we can just scan the list
    5459             :      * rather than recursing through the expression trees.
    5460             :      */
    5461        8250 :     foreach(lc, partial_target->exprs)
    5462             :     {
    5463        6102 :         Aggref     *aggref = (Aggref *) lfirst(lc);
    5464             : 
    5465        6102 :         if (IsA(aggref, Aggref))
    5466             :         {
    5467             :             Aggref     *newaggref;
    5468             : 
    5469             :             /*
    5470             :              * We shouldn't need to copy the substructure of the Aggref node,
    5471             :              * but flat-copy the node itself to avoid damaging other trees.
    5472             :              */
    5473        4208 :             newaggref = makeNode(Aggref);
    5474        4208 :             memcpy(newaggref, aggref, sizeof(Aggref));
    5475             : 
    5476             :             /* For now, assume serialization is required */
    5477        4208 :             mark_partial_aggref(newaggref, AGGSPLIT_INITIAL_SERIAL);
    5478             : 
    5479        4208 :             lfirst(lc) = newaggref;
    5480             :         }
    5481             :     }
    5482             : 
    5483             :     /* clean up cruft */
    5484        2148 :     list_free(non_group_exprs);
    5485        2148 :     list_free(non_group_cols);
    5486             : 
    5487             :     /* XXX this causes some redundant cost calculation ... */
    5488        2148 :     return set_pathtarget_cost_width(root, partial_target);
    5489             : }
    5490             : 
    5491             : /*
    5492             :  * mark_partial_aggref
    5493             :  *    Adjust an Aggref to make it represent a partial-aggregation step.
    5494             :  *
    5495             :  * The Aggref node is modified in-place; caller must do any copying required.
    5496             :  */
    5497             : void
    5498        7000 : mark_partial_aggref(Aggref *agg, AggSplit aggsplit)
    5499             : {
    5500             :     /* aggtranstype should be computed by this point */
    5501             :     Assert(OidIsValid(agg->aggtranstype));
    5502             :     /* ... but aggsplit should still be as the parser left it */
    5503             :     Assert(agg->aggsplit == AGGSPLIT_SIMPLE);
    5504             : 
    5505             :     /* Mark the Aggref with the intended partial-aggregation mode */
    5506        7000 :     agg->aggsplit = aggsplit;
    5507             : 
    5508             :     /*
    5509             :      * Adjust result type if needed.  Normally, a partial aggregate returns
    5510             :      * the aggregate's transition type; but if that's INTERNAL and we're
    5511             :      * serializing, it returns BYTEA instead.
    5512             :      */
    5513        7000 :     if (DO_AGGSPLIT_SKIPFINAL(aggsplit))
    5514             :     {
    5515        5604 :         if (agg->aggtranstype == INTERNALOID && DO_AGGSPLIT_SERIALIZE(aggsplit))
    5516         242 :             agg->aggtype = BYTEAOID;
    5517             :         else
    5518        5362 :             agg->aggtype = agg->aggtranstype;
    5519             :     }
    5520        7000 : }
    5521             : 
    5522             : /*
    5523             :  * postprocess_setop_tlist
    5524             :  *    Fix up targetlist returned by plan_set_operations().
    5525             :  *
    5526             :  * We need to transpose sort key info from the orig_tlist into new_tlist.
    5527             :  * NOTE: this would not be good enough if we supported resjunk sort keys
    5528             :  * for results of set operations --- then, we'd need to project a whole
    5529             :  * new tlist to evaluate the resjunk columns.  For now, just ereport if we
    5530             :  * find any resjunk columns in orig_tlist.
    5531             :  */
    5532             : static List *
    5533        5152 : postprocess_setop_tlist(List *new_tlist, List *orig_tlist)
    5534             : {
    5535             :     ListCell   *l;
    5536        5152 :     ListCell   *orig_tlist_item = list_head(orig_tlist);
    5537             : 
    5538       19854 :     foreach(l, new_tlist)
    5539             :     {
    5540       14702 :         TargetEntry *new_tle = lfirst_node(TargetEntry, l);
    5541             :         TargetEntry *orig_tle;
    5542             : 
    5543             :         /* ignore resjunk columns in setop result */
    5544       14702 :         if (new_tle->resjunk)
    5545         510 :             continue;
    5546             : 
    5547             :         Assert(orig_tlist_item != NULL);
    5548       14192 :         orig_tle = lfirst_node(TargetEntry, orig_tlist_item);
    5549       14192 :         orig_tlist_item = lnext(orig_tlist, orig_tlist_item);
    5550       14192 :         if (orig_tle->resjunk)   /* should not happen */
    5551           0 :             elog(ERROR, "resjunk output columns are not implemented");
    5552             :         Assert(new_tle->resno == orig_tle->resno);
    5553       14192 :         new_tle->ressortgroupref = orig_tle->ressortgroupref;
    5554             :     }
    5555        5152 :     if (orig_tlist_item != NULL)
    5556           0 :         elog(ERROR, "resjunk output columns are not implemented");
    5557        5152 :     return new_tlist;
    5558             : }
    5559             : 
    5560             : /*
    5561             :  * optimize_window_clauses
    5562             :  *      Call each WindowFunc's prosupport function to see if we're able to
    5563             :  *      make any adjustments to any of the WindowClause's so that the executor
    5564             :  *      can execute the window functions in a more optimal way.
    5565             :  *
    5566             :  * Currently we only allow adjustments to the WindowClause's frameOptions.  We
    5567             :  * may allow more things to be done here in the future.
    5568             :  */
    5569             : static void
    5570        2294 : optimize_window_clauses(PlannerInfo *root, WindowFuncLists *wflists)
    5571             : {
    5572        2294 :     List       *windowClause = root->parse->windowClause;
    5573             :     ListCell   *lc;
    5574             : 
    5575        4798 :     foreach(lc, windowClause)
    5576             :     {
    5577        2504 :         WindowClause *wc = lfirst_node(WindowClause, lc);
    5578             :         ListCell   *lc2;
    5579        2504 :         int         optimizedFrameOptions = 0;
    5580             : 
    5581             :         Assert(wc->winref <= wflists->maxWinRef);
    5582             : 
    5583             :         /* skip any WindowClauses that have no WindowFuncs */
    5584        2504 :         if (wflists->windowFuncs[wc->winref] == NIL)
    5585          24 :             continue;
    5586             : 
    5587        2996 :         foreach(lc2, wflists->windowFuncs[wc->winref])
    5588             :         {
    5589             :             SupportRequestOptimizeWindowClause req;
    5590             :             SupportRequestOptimizeWindowClause *res;
    5591        2516 :             WindowFunc *wfunc = lfirst_node(WindowFunc, lc2);
    5592             :             Oid         prosupport;
    5593             : 
    5594        2516 :             prosupport = get_func_support(wfunc->winfnoid);
    5595             : 
    5596             :             /* Check if there's a support function for 'wfunc' */
    5597        2516 :             if (!OidIsValid(prosupport))
    5598        2000 :                 break;          /* can't optimize this WindowClause */
    5599             : 
    5600         736 :             req.type = T_SupportRequestOptimizeWindowClause;
    5601         736 :             req.window_clause = wc;
    5602         736 :             req.window_func = wfunc;
    5603         736 :             req.frameOptions = wc->frameOptions;
    5604             : 
    5605             :             /* call the support function */
    5606             :             res = (SupportRequestOptimizeWindowClause *)
    5607         736 :                 DatumGetPointer(OidFunctionCall1(prosupport,
    5608             :                                                  PointerGetDatum(&req)));
    5609             : 
    5610             :             /*
    5611             :              * Skip to next WindowClause if the support function does not
    5612             :              * support this request type.
    5613             :              */
    5614         736 :             if (res == NULL)
    5615         220 :                 break;
    5616             : 
    5617             :             /*
    5618             :              * Save these frameOptions for the first WindowFunc for this
    5619             :              * WindowClause.
    5620             :              */
    5621         516 :             if (foreach_current_index(lc2) == 0)
    5622         492 :                 optimizedFrameOptions = res->frameOptions;
    5623             : 
    5624             :             /*
    5625             :              * On subsequent WindowFuncs, if the frameOptions are not the same
    5626             :              * then we're unable to optimize the frameOptions for this
    5627             :              * WindowClause.
    5628             :              */
    5629          24 :             else if (optimizedFrameOptions != res->frameOptions)
    5630           0 :                 break;          /* skip to the next WindowClause, if any */
    5631             :         }
    5632             : 
    5633             :         /* adjust the frameOptions if all WindowFunc's agree that it's ok */
    5634        2480 :         if (lc2 == NULL && wc->frameOptions != optimizedFrameOptions)
    5635             :         {
    5636             :             ListCell   *lc3;
    5637             : 
    5638             :             /* apply the new frame options */
    5639         480 :             wc->frameOptions = optimizedFrameOptions;
    5640             : 
    5641             :             /*
    5642             :              * We now check to see if changing the frameOptions has caused
    5643             :              * this WindowClause to be a duplicate of some other WindowClause.
    5644             :              * This can only happen if we have multiple WindowClauses, so
    5645             :              * don't bother if there's only 1.
    5646             :              */
    5647         480 :             if (list_length(windowClause) == 1)
    5648         390 :                 continue;
    5649             : 
    5650             :             /*
    5651             :              * Do the duplicate check and reuse the existing WindowClause if
    5652             :              * we find a duplicate.
    5653             :              */
    5654         228 :             foreach(lc3, windowClause)
    5655             :             {
    5656         174 :                 WindowClause *existing_wc = lfirst_node(WindowClause, lc3);
    5657             : 
    5658             :                 /* skip over the WindowClause we're currently editing */
    5659         174 :                 if (existing_wc == wc)
    5660          54 :                     continue;
    5661             : 
    5662             :                 /*
    5663             :                  * Perform the same duplicate check that is done in
    5664             :                  * transformWindowFuncCall.
    5665             :                  */
    5666         240 :                 if (equal(wc->partitionClause, existing_wc->partitionClause) &&
    5667         120 :                     equal(wc->orderClause, existing_wc->orderClause) &&
    5668         120 :                     wc->frameOptions == existing_wc->frameOptions &&
    5669          72 :                     equal(wc->startOffset, existing_wc->startOffset) &&
    5670          36 :                     equal(wc->endOffset, existing_wc->endOffset))
    5671             :                 {
    5672             :                     ListCell   *lc4;
    5673             : 
    5674             :                     /*
    5675             :                      * Now move each WindowFunc in 'wc' into 'existing_wc'.
    5676             :                      * This required adjusting each WindowFunc's winref and
    5677             :                      * moving the WindowFuncs in 'wc' to the list of
    5678             :                      * WindowFuncs in 'existing_wc'.
    5679             :                      */
    5680          78 :                     foreach(lc4, wflists->windowFuncs[wc->winref])
    5681             :                     {
    5682          42 :                         WindowFunc *wfunc = lfirst_node(WindowFunc, lc4);
    5683             : 
    5684          42 :                         wfunc->winref = existing_wc->winref;
    5685             :                     }
    5686             : 
    5687             :                     /* move list items */
    5688          72 :                     wflists->windowFuncs[existing_wc->winref] = list_concat(wflists->windowFuncs[existing_wc->winref],
    5689          36 :                                                                             wflists->windowFuncs[wc->winref]);
    5690          36 :                     wflists->windowFuncs[wc->winref] = NIL;
    5691             : 
    5692             :                     /*
    5693             :                      * transformWindowFuncCall() should have made sure there
    5694             :                      * are no other duplicates, so we needn't bother looking
    5695             :                      * any further.
    5696             :                      */
    5697          36 :                     break;
    5698             :                 }
    5699             :             }
    5700             :         }
    5701             :     }
    5702        2294 : }
    5703             : 
    5704             : /*
    5705             :  * select_active_windows
    5706             :  *      Create a list of the "active" window clauses (ie, those referenced
    5707             :  *      by non-deleted WindowFuncs) in the order they are to be executed.
    5708             :  */
    5709             : static List *
    5710        2294 : select_active_windows(PlannerInfo *root, WindowFuncLists *wflists)
    5711             : {
    5712        2294 :     List       *windowClause = root->parse->windowClause;
    5713        2294 :     List       *result = NIL;
    5714             :     ListCell   *lc;
    5715        2294 :     int         nActive = 0;
    5716        2294 :     WindowClauseSortData *actives = palloc(sizeof(WindowClauseSortData)
    5717        2294 :                                            * list_length(windowClause));
    5718             : 
    5719             :     /* First, construct an array of the active windows */
    5720        4798 :     foreach(lc, windowClause)
    5721             :     {
    5722        2504 :         WindowClause *wc = lfirst_node(WindowClause, lc);
    5723             : 
    5724             :         /* It's only active if wflists shows some related WindowFuncs */
    5725             :         Assert(wc->winref <= wflists->maxWinRef);
    5726        2504 :         if (wflists->windowFuncs[wc->winref] == NIL)
    5727          60 :             continue;
    5728             : 
    5729        2444 :         actives[nActive].wc = wc;   /* original clause */
    5730             : 
    5731             :         /*
    5732             :          * For sorting, we want the list of partition keys followed by the
    5733             :          * list of sort keys. But pathkeys construction will remove duplicates
    5734             :          * between the two, so we can as well (even though we can't detect all
    5735             :          * of the duplicates, since some may come from ECs - that might mean
    5736             :          * we miss optimization chances here). We must, however, ensure that
    5737             :          * the order of entries is preserved with respect to the ones we do
    5738             :          * keep.
    5739             :          *
    5740             :          * partitionClause and orderClause had their own duplicates removed in
    5741             :          * parse analysis, so we're only concerned here with removing
    5742             :          * orderClause entries that also appear in partitionClause.
    5743             :          */
    5744        4888 :         actives[nActive].uniqueOrder =
    5745        2444 :             list_concat_unique(list_copy(wc->partitionClause),
    5746        2444 :                                wc->orderClause);
    5747        2444 :         nActive++;
    5748             :     }
    5749             : 
    5750             :     /*
    5751             :      * Sort active windows by their partitioning/ordering clauses, ignoring
    5752             :      * any framing clauses, so that the windows that need the same sorting are
    5753             :      * adjacent in the list. When we come to generate paths, this will avoid
    5754             :      * inserting additional Sort nodes.
    5755             :      *
    5756             :      * This is how we implement a specific requirement from the SQL standard,
    5757             :      * which says that when two or more windows are order-equivalent (i.e.
    5758             :      * have matching partition and order clauses, even if their names or
    5759             :      * framing clauses differ), then all peer rows must be presented in the
    5760             :      * same order in all of them. If we allowed multiple sort nodes for such
    5761             :      * cases, we'd risk having the peer rows end up in different orders in
    5762             :      * equivalent windows due to sort instability. (See General Rule 4 of
    5763             :      * <window clause> in SQL2008 - SQL2016.)
    5764             :      *
    5765             :      * Additionally, if the entire list of clauses of one window is a prefix
    5766             :      * of another, put first the window with stronger sorting requirements.
    5767             :      * This way we will first sort for stronger window, and won't have to sort
    5768             :      * again for the weaker one.
    5769             :      */
    5770        2294 :     qsort(actives, nActive, sizeof(WindowClauseSortData), common_prefix_cmp);
    5771             : 
    5772             :     /* build ordered list of the original WindowClause nodes */
    5773        4738 :     for (int i = 0; i < nActive; i++)
    5774        2444 :         result = lappend(result, actives[i].wc);
    5775             : 
    5776        2294 :     pfree(actives);
    5777             : 
    5778        2294 :     return result;
    5779             : }
    5780             : 
    5781             : /*
    5782             :  * common_prefix_cmp
    5783             :  *    QSort comparison function for WindowClauseSortData
    5784             :  *
    5785             :  * Sort the windows by the required sorting clauses. First, compare the sort
    5786             :  * clauses themselves. Second, if one window's clauses are a prefix of another
    5787             :  * one's clauses, put the window with more sort clauses first.
    5788             :  *
    5789             :  * We purposefully sort by the highest tleSortGroupRef first.  Since
    5790             :  * tleSortGroupRefs are assigned for the query's DISTINCT and ORDER BY first
    5791             :  * and because here we sort the lowest tleSortGroupRefs last, if a
    5792             :  * WindowClause is sharing a tleSortGroupRef with the query's DISTINCT or
    5793             :  * ORDER BY clause, this makes it more likely that the final WindowAgg will
    5794             :  * provide presorted input for the query's DISTINCT or ORDER BY clause, thus
    5795             :  * reducing the total number of sorts required for the query.
    5796             :  */
    5797             : static int
    5798         162 : common_prefix_cmp(const void *a, const void *b)
    5799             : {
    5800         162 :     const WindowClauseSortData *wcsa = a;
    5801         162 :     const WindowClauseSortData *wcsb = b;
    5802             :     ListCell   *item_a;
    5803             :     ListCell   *item_b;
    5804             : 
    5805         276 :     forboth(item_a, wcsa->uniqueOrder, item_b, wcsb->uniqueOrder)
    5806             :     {
    5807         216 :         SortGroupClause *sca = lfirst_node(SortGroupClause, item_a);
    5808         216 :         SortGroupClause *scb = lfirst_node(SortGroupClause, item_b);
    5809             : 
    5810         216 :         if (sca->tleSortGroupRef > scb->tleSortGroupRef)
    5811         102 :             return -1;
    5812         204 :         else if (sca->tleSortGroupRef < scb->tleSortGroupRef)
    5813          66 :             return 1;
    5814         138 :         else if (sca->sortop > scb->sortop)
    5815           0 :             return -1;
    5816         138 :         else if (sca->sortop < scb->sortop)
    5817          24 :             return 1;
    5818         114 :         else if (sca->nulls_first && !scb->nulls_first)
    5819           0 :             return -1;
    5820         114 :         else if (!sca->nulls_first && scb->nulls_first)
    5821           0 :             return 1;
    5822             :         /* no need to compare eqop, since it is fully determined by sortop */
    5823             :     }
    5824             : 
    5825          60 :     if (list_length(wcsa->uniqueOrder) > list_length(wcsb->uniqueOrder))
    5826           6 :         return -1;
    5827          54 :     else if (list_length(wcsa->uniqueOrder) < list_length(wcsb->uniqueOrder))
    5828          12 :         return 1;
    5829             : 
    5830          42 :     return 0;
    5831             : }
    5832             : 
    5833             : /*
    5834             :  * make_window_input_target
    5835             :  *    Generate appropriate PathTarget for initial input to WindowAgg nodes.
    5836             :  *
    5837             :  * When the query has window functions, this function computes the desired
    5838             :  * target to be computed by the node just below the first WindowAgg.
    5839             :  * This tlist must contain all values needed to evaluate the window functions,
    5840             :  * compute the final target list, and perform any required final sort step.
    5841             :  * If multiple WindowAggs are needed, each intermediate one adds its window
    5842             :  * function results onto this base tlist; only the topmost WindowAgg computes
    5843             :  * the actual desired target list.
    5844             :  *
    5845             :  * This function is much like make_group_input_target, though not quite enough
    5846             :  * like it to share code.  As in that function, we flatten most expressions
    5847             :  * into their component variables.  But we do not want to flatten window
    5848             :  * PARTITION BY/ORDER BY clauses, since that might result in multiple
    5849             :  * evaluations of them, which would be bad (possibly even resulting in
    5850             :  * inconsistent answers, if they contain volatile functions).
    5851             :  * Also, we must not flatten GROUP BY clauses that were left unflattened by
    5852             :  * make_group_input_target, because we may no longer have access to the
    5853             :  * individual Vars in them.
    5854             :  *
    5855             :  * Another key difference from make_group_input_target is that we don't
    5856             :  * flatten Aggref expressions, since those are to be computed below the
    5857             :  * window functions and just referenced like Vars above that.
    5858             :  *
    5859             :  * 'final_target' is the query's final target list (in PathTarget form)
    5860             :  * 'activeWindows' is the list of active windows previously identified by
    5861             :  *          select_active_windows.
    5862             :  *
    5863             :  * The result is the PathTarget to be computed by the plan node immediately
    5864             :  * below the first WindowAgg node.
    5865             :  */
    5866             : static PathTarget *
    5867        2294 : make_window_input_target(PlannerInfo *root,
    5868             :                          PathTarget *final_target,
    5869             :                          List *activeWindows)
    5870             : {
    5871             :     PathTarget *input_target;
    5872             :     Bitmapset  *sgrefs;
    5873             :     List       *flattenable_cols;
    5874             :     List       *flattenable_vars;
    5875             :     int         i;
    5876             :     ListCell   *lc;
    5877             : 
    5878             :     Assert(root->parse->hasWindowFuncs);
    5879             : 
    5880             :     /*
    5881             :      * Collect the sortgroupref numbers of window PARTITION/ORDER BY clauses
    5882             :      * into a bitmapset for convenient reference below.
    5883             :      */
    5884        2294 :     sgrefs = NULL;
    5885        4738 :     foreach(lc, activeWindows)
    5886             :     {
    5887        2444 :         WindowClause *wc = lfirst_node(WindowClause, lc);
    5888             :         ListCell   *lc2;
    5889             : 
    5890        3144 :         foreach(lc2, wc->partitionClause)
    5891             :         {
    5892         700 :             SortGroupClause *sortcl = lfirst_node(SortGroupClause, lc2);
    5893             : 
    5894         700 :             sgrefs = bms_add_member(sgrefs, sortcl->tleSortGroupRef);
    5895             :         }
    5896        4564 :         foreach(lc2, wc->orderClause)
    5897             :         {
    5898        2120 :             SortGroupClause *sortcl = lfirst_node(SortGroupClause, lc2);
    5899             : 
    5900        2120 :             sgrefs = bms_add_member(sgrefs, sortcl->tleSortGroupRef);
    5901             :         }
    5902             :     }
    5903             : 
    5904             :     /* Add in sortgroupref numbers of GROUP BY clauses, too */
    5905        2456 :     foreach(lc, root->processed_groupClause)
    5906             :     {
    5907         162 :         SortGroupClause *grpcl = lfirst_node(SortGroupClause, lc);
    5908             : 
    5909         162 :         sgrefs = bms_add_member(sgrefs, grpcl->tleSortGroupRef);
    5910             :     }
    5911             : 
    5912             :     /*
    5913             :      * Construct a target containing all the non-flattenable targetlist items,
    5914             :      * and save aside the others for a moment.
    5915             :      */
    5916        2294 :     input_target = create_empty_pathtarget();
    5917        2294 :     flattenable_cols = NIL;
    5918             : 
    5919        2294 :     i = 0;
    5920        9988 :     foreach(lc, final_target->exprs)
    5921             :     {
    5922        7694 :         Expr       *expr = (Expr *) lfirst(lc);
    5923        7694 :         Index       sgref = get_pathtarget_sortgroupref(final_target, i);
    5924             : 
    5925             :         /*
    5926             :          * Don't want to deconstruct window clauses or GROUP BY items.  (Note
    5927             :          * that such items can't contain window functions, so it's okay to
    5928             :          * compute them below the WindowAgg nodes.)
    5929             :          */
    5930        7694 :         if (sgref != 0 && bms_is_member(sgref, sgrefs))
    5931             :         {
    5932             :             /*
    5933             :              * Don't want to deconstruct this value, so add it to the input
    5934             :              * target as-is.
    5935             :              */
    5936        2710 :             add_column_to_pathtarget(input_target, expr, sgref);
    5937             :         }
    5938             :         else
    5939             :         {
    5940             :             /*
    5941             :              * Column is to be flattened, so just remember the expression for
    5942             :              * later call to pull_var_clause.
    5943             :              */
    5944        4984 :             flattenable_cols = lappend(flattenable_cols, expr);
    5945             :         }
    5946             : 
    5947        7694 :         i++;
    5948             :     }
    5949             : 
    5950             :     /*
    5951             :      * Pull out all the Vars and Aggrefs mentioned in flattenable columns, and
    5952             :      * add them to the input target if not already present.  (Some might be
    5953             :      * there already because they're used directly as window/group clauses.)
    5954             :      *
    5955             :      * Note: it's essential to use PVC_INCLUDE_AGGREGATES here, so that any
    5956             :      * Aggrefs are placed in the Agg node's tlist and not left to be computed
    5957             :      * at higher levels.  On the other hand, we should recurse into
    5958             :      * WindowFuncs to make sure their input expressions are available.
    5959             :      */
    5960        2294 :     flattenable_vars = pull_var_clause((Node *) flattenable_cols,
    5961             :                                        PVC_INCLUDE_AGGREGATES |
    5962             :                                        PVC_RECURSE_WINDOWFUNCS |
    5963             :                                        PVC_INCLUDE_PLACEHOLDERS);
    5964        2294 :     add_new_columns_to_pathtarget(input_target, flattenable_vars);
    5965             : 
    5966             :     /* clean up cruft */
    5967        2294 :     list_free(flattenable_vars);
    5968        2294 :     list_free(flattenable_cols);
    5969             : 
    5970             :     /* XXX this causes some redundant cost calculation ... */
    5971        2294 :     return set_pathtarget_cost_width(root, input_target);
    5972             : }
    5973             : 
    5974             : /*
    5975             :  * make_pathkeys_for_window
    5976             :  *      Create a pathkeys list describing the required input ordering
    5977             :  *      for the given WindowClause.
    5978             :  *
    5979             :  * Modifies wc's partitionClause to remove any clauses which are deemed
    5980             :  * redundant by the pathkey logic.
    5981             :  *
    5982             :  * The required ordering is first the PARTITION keys, then the ORDER keys.
    5983             :  * In the future we might try to implement windowing using hashing, in which
    5984             :  * case the ordering could be relaxed, but for now we always sort.
    5985             :  */
    5986             : static List *
    5987        4924 : make_pathkeys_for_window(PlannerInfo *root, WindowClause *wc,
    5988             :                          List *tlist)
    5989             : {
    5990        4924 :     List       *window_pathkeys = NIL;
    5991             : 
    5992             :     /* Throw error if can't sort */
    5993        4924 :     if (!grouping_is_sortable(wc->partitionClause))
    5994           0 :         ereport(ERROR,
    5995             :                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
    5996             :                  errmsg("could not implement window PARTITION BY"),
    5997             :                  errdetail("Window partitioning columns must be of sortable datatypes.")));
    5998        4924 :     if (!grouping_is_sortable(wc->orderClause))
    5999           0 :         ereport(ERROR,
    6000             :                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
    6001             :                  errmsg("could not implement window ORDER BY"),
    6002             :                  errdetail("Window ordering columns must be of sortable datatypes.")));
    6003             : 
    6004             :     /*
    6005             :      * First fetch the pathkeys for the PARTITION BY clause.  We can safely
    6006             :      * remove any clauses from the wc->partitionClause for redundant pathkeys.
    6007             :      */
    6008        4924 :     if (wc->partitionClause != NIL)
    6009             :     {
    6010             :         bool        sortable;
    6011             : 
    6012        1174 :         window_pathkeys = make_pathkeys_for_sortclauses_extended(root,
    6013             :                                                                  &wc->partitionClause,
    6014             :                                                                  tlist,
    6015             :                                                                  true,
    6016             :                                                                  &sortable);
    6017             : 
    6018             :         Assert(sortable);
    6019             :     }
    6020             : 
    6021             :     /*
    6022             :      * In principle, we could also consider removing redundant ORDER BY items
    6023             :      * too as doing so does not alter the result of peer row checks done by
    6024             :      * the executor.  However, we must *not* remove the ordering column for
    6025             :      * RANGE OFFSET cases, as the executor needs that for in_range tests even
    6026             :      * if it's known to be equal to some partitioning column.
    6027             :      */
    6028        4924 :     if (wc->orderClause != NIL)
    6029             :     {
    6030             :         List       *orderby_pathkeys;
    6031             : 
    6032        4174 :         orderby_pathkeys = make_pathkeys_for_sortclauses(root,
    6033             :                                                          wc->orderClause,
    6034             :                                                          tlist);
    6035             : 
    6036             :         /* Okay, make the combined pathkeys */
    6037        4174 :         if (window_pathkeys != NIL)
    6038         880 :             window_pathkeys = append_pathkeys(window_pathkeys, orderby_pathkeys);
    6039             :         else
    6040        3294 :             window_pathkeys = orderby_pathkeys;
    6041             :     }
    6042             : 
    6043        4924 :     return window_pathkeys;
    6044             : }
    6045             : 
    6046             : /*
    6047             :  * make_sort_input_target
    6048             :  *    Generate appropriate PathTarget for initial input to Sort step.
    6049             :  *
    6050             :  * If the query has ORDER BY, this function chooses the target to be computed
    6051             :  * by the node just below the Sort (and DISTINCT, if any, since Unique can't
    6052             :  * project) steps.  This might or might not be identical to the query's final
    6053             :  * output target.
    6054             :  *
    6055             :  * The main argument for keeping the sort-input tlist the same as the final
    6056             :  * is that we avoid a separate projection node (which will be needed if
    6057             :  * they're different, because Sort can't project).  However, there are also
    6058             :  * advantages to postponing tlist evaluation till after the Sort: it ensures
    6059             :  * a consistent order of evaluation for any volatile functions in the tlist,
    6060             :  * and if there's also a LIMIT, we can stop the query without ever computing
    6061             :  * tlist functions for later rows, which is beneficial for both volatile and
    6062             :  * expensive functions.
    6063             :  *
    6064             :  * Our current policy is to postpone volatile expressions till after the sort
    6065             :  * unconditionally (assuming that that's possible, ie they are in plain tlist
    6066             :  * columns and not ORDER BY/GROUP BY/DISTINCT columns).  We also prefer to
    6067             :  * postpone set-returning expressions, because running them beforehand would
    6068             :  * bloat the sort dataset, and because it might cause unexpected output order
    6069             :  * if the sort isn't stable.  However there's a constraint on that: all SRFs
    6070             :  * in the tlist should be evaluated at the same plan step, so that they can
    6071             :  * run in sync in nodeProjectSet.  So if any SRFs are in sort columns, we
    6072             :  * mustn't postpone any SRFs.  (Note that in principle that policy should
    6073             :  * probably get applied to the group/window input targetlists too, but we
    6074             :  * have not done that historically.)  Lastly, expensive expressions are
    6075             :  * postponed if there is a LIMIT, or if root->tuple_fraction shows that
    6076             :  * partial evaluation of the query is possible (if neither is true, we expect
    6077             :  * to have to evaluate the expressions for every row anyway), or if there are
    6078             :  * any volatile or set-returning expressions (since once we've put in a
    6079             :  * projection at all, it won't cost any more to postpone more stuff).
    6080             :  *
    6081             :  * Another issue that could potentially be considered here is that
    6082             :  * evaluating tlist expressions could result in data that's either wider
    6083             :  * or narrower than the input Vars, thus changing the volume of data that
    6084             :  * has to go through the Sort.  However, we usually have only a very bad
    6085             :  * idea of the output width of any expression more complex than a Var,
    6086             :  * so for now it seems too risky to try to optimize on that basis.
    6087             :  *
    6088             :  * Note that if we do produce a modified sort-input target, and then the
    6089             :  * query ends up not using an explicit Sort, no particular harm is done:
    6090             :  * we'll initially use the modified target for the preceding path nodes,
    6091             :  * but then change them to the final target with apply_projection_to_path.
    6092             :  * Moreover, in such a case the guarantees about evaluation order of
    6093             :  * volatile functions still hold, since the rows are sorted already.
    6094             :  *
    6095             :  * This function has some things in common with make_group_input_target and
    6096             :  * make_window_input_target, though the detailed rules for what to do are
    6097             :  * different.  We never flatten/postpone any grouping or ordering columns;
    6098             :  * those are needed before the sort.  If we do flatten a particular
    6099             :  * expression, we leave Aggref and WindowFunc nodes alone, since those were
    6100             :  * computed earlier.
    6101             :  *
    6102             :  * 'final_target' is the query's final target list (in PathTarget form)
    6103             :  * 'have_postponed_srfs' is an output argument, see below
    6104             :  *
    6105             :  * The result is the PathTarget to be computed by the plan node immediately
    6106             :  * below the Sort step (and the Distinct step, if any).  This will be
    6107             :  * exactly final_target if we decide a projection step wouldn't be helpful.
    6108             :  *
    6109             :  * In addition, *have_postponed_srfs is set to true if we choose to postpone
    6110             :  * any set-returning functions to after the Sort.
    6111             :  */
    6112             : static PathTarget *
    6113       53510 : make_sort_input_target(PlannerInfo *root,
    6114             :                        PathTarget *final_target,
    6115             :                        bool *have_postponed_srfs)
    6116             : {
    6117       53510 :     Query      *parse = root->parse;
    6118             :     PathTarget *input_target;
    6119             :     int         ncols;
    6120             :     bool       *col_is_srf;
    6121             :     bool       *postpone_col;
    6122             :     bool        have_srf;
    6123             :     bool        have_volatile;
    6124             :     bool        have_expensive;
    6125             :     bool        have_srf_sortcols;
    6126             :     bool        postpone_srfs;
    6127             :     List       *postponable_cols;
    6128             :     List       *postponable_vars;
    6129             :     int         i;
    6130             :     ListCell   *lc;
    6131             : 
    6132             :     /* Shouldn't get here unless query has ORDER BY */
    6133             :     Assert(parse->sortClause);
    6134             : 
    6135       53510 :     *have_postponed_srfs = false;   /* default result */
    6136             : 
    6137             :     /* Inspect tlist and collect per-column information */
    6138       53510 :     ncols = list_length(final_target->exprs);
    6139       53510 :     col_is_srf = (bool *) palloc0(ncols * sizeof(bool));
    6140       53510 :     postpone_col = (bool *) palloc0(ncols * sizeof(bool));
    6141       53510 :     have_srf = have_volatile = have_expensive = have_srf_sortcols = false;
    6142             : 
    6143       53510 :     i = 0;
    6144      321750 :     foreach(lc, final_target->exprs)
    6145             :     {
    6146      268240 :         Expr       *expr = (Expr *) lfirst(lc);
    6147             : 
    6148             :         /*
    6149             :          * If the column has a sortgroupref, assume it has to be evaluated
    6150             :          * before sorting.  Generally such columns would be ORDER BY, GROUP
    6151             :          * BY, etc targets.  One exception is columns that were removed from
    6152             :          * GROUP BY by remove_useless_groupby_columns() ... but those would
    6153             :          * only be Vars anyway.  There don't seem to be any cases where it
    6154             :          * would be worth the trouble to double-check.
    6155             :          */
    6156      268240 :         if (get_pathtarget_sortgroupref(final_target, i) == 0)
    6157             :         {
    6158             :             /*
    6159             :              * Check for SRF or volatile functions.  Check the SRF case first
    6160             :              * because we must know whether we have any postponed SRFs.
    6161             :              */
    6162      191406 :             if (parse->hasTargetSRFs &&
    6163         216 :                 expression_returns_set((Node *) expr))
    6164             :             {
    6165             :                 /* We'll decide below whether these are postponable */
    6166          96 :                 col_is_srf[i] = true;
    6167          96 :                 have_srf = true;
    6168             :             }
    6169      191094 :             else if (contain_volatile_functions((Node *) expr))
    6170             :             {
    6171             :                 /* Unconditionally postpone */
    6172         142 :                 postpone_col[i] = true;
    6173         142 :                 have_volatile = true;
    6174             :             }
    6175             :             else
    6176             :             {
    6177             :                 /*
    6178             :                  * Else check the cost.  XXX it's annoying to have to do this
    6179             :                  * when set_pathtarget_cost_width() just did it.  Refactor to
    6180             :                  * allow sharing the work?
    6181             :                  */
    6182             :                 QualCost    cost;
    6183             : 
    6184      190952 :                 cost_qual_eval_node(&cost, (Node *) expr, root);
    6185             : 
    6186             :                 /*
    6187             :                  * We arbitrarily define "expensive" as "more than 10X
    6188             :                  * cpu_operator_cost".  Note this will take in any PL function
    6189             :                  * with default cost.
    6190             :                  */
    6191      190952 :                 if (cost.per_tuple > 10 * cpu_operator_cost)
    6192             :                 {
    6193       14036 :                     postpone_col[i] = true;
    6194       14036 :                     have_expensive = true;
    6195             :                 }
    6196             :             }
    6197             :         }
    6198             :         else
    6199             :         {
    6200             :             /* For sortgroupref cols, just check if any contain SRFs */
    6201       77050 :             if (!have_srf_sortcols &&
    6202       77360 :                 parse->hasTargetSRFs &&
    6203         310 :                 expression_returns_set((Node *) expr))
    6204         124 :                 have_srf_sortcols = true;
    6205             :         }
    6206             : 
    6207      268240 :         i++;
    6208             :     }
    6209             : 
    6210             :     /*
    6211             :      * We can postpone SRFs if we have some but none are in sortgroupref cols.
    6212             :      */
    6213       53510 :     postpone_srfs = (have_srf && !have_srf_sortcols);
    6214             : 
    6215             :     /*
    6216             :      * If we don't need a post-sort projection, just return final_target.
    6217             :      */
    6218       53510 :     if (!(postpone_srfs || have_volatile ||
    6219       53312 :           (have_expensive &&
    6220        8452 :            (parse->limitCount || root->tuple_fraction > 0))))
    6221       53276 :         return final_target;
    6222             : 
    6223             :     /*
    6224             :      * Report whether the post-sort projection will contain set-returning
    6225             :      * functions.  This is important because it affects whether the Sort can
    6226             :      * rely on the query's LIMIT (if any) to bound the number of rows it needs
    6227             :      * to return.
    6228             :      */
    6229         234 :     *have_postponed_srfs = postpone_srfs;
    6230             : 
    6231             :     /*
    6232             :      * Construct the sort-input target, taking all non-postponable columns and
    6233             :      * then adding Vars, PlaceHolderVars, Aggrefs, and WindowFuncs found in
    6234             :      * the postponable ones.
    6235             :      */
    6236         234 :     input_target = create_empty_pathtarget();
    6237         234 :     postponable_cols = NIL;
    6238             : 
    6239         234 :     i = 0;
    6240        1942 :     foreach(lc, final_target->exprs)
    6241             :     {
    6242        1708 :         Expr       *expr = (Expr *) lfirst(lc);
    6243             : 
    6244        1708 :         if (postpone_col[i] || (postpone_srfs && col_is_srf[i]))
    6245         286 :             postponable_cols = lappend(postponable_cols, expr);
    6246             :         else
    6247        1422 :             add_column_to_pathtarget(input_target, expr,
    6248        1422 :                                      get_pathtarget_sortgroupref(final_target, i));
    6249             : 
    6250        1708 :         i++;
    6251             :     }
    6252             : 
    6253             :     /*
    6254             :      * Pull out all the Vars, Aggrefs, and WindowFuncs mentioned in
    6255             :      * postponable columns, and add them to the sort-input target if not
    6256             :      * already present.  (Some might be there already.)  We mustn't
    6257             :      * deconstruct Aggrefs or WindowFuncs here, since the projection node
    6258             :      * would be unable to recompute them.
    6259             :      */
    6260         234 :     postponable_vars = pull_var_clause((Node *) postponable_cols,
    6261             :                                        PVC_INCLUDE_AGGREGATES |
    6262             :                                        PVC_INCLUDE_WINDOWFUNCS |
    6263             :                                        PVC_INCLUDE_PLACEHOLDERS);
    6264         234 :     add_new_columns_to_pathtarget(input_target, postponable_vars);
    6265             : 
    6266             :     /* clean up cruft */
    6267         234 :     list_free(postponable_vars);
    6268         234 :     list_free(postponable_cols);
    6269             : 
    6270             :     /* XXX this represents even more redundant cost calculation ... */
    6271         234 :     return set_pathtarget_cost_width(root, input_target);
    6272             : }
    6273             : 
    6274             : /*
    6275             :  * get_cheapest_fractional_path
    6276             :  *    Find the cheapest path for retrieving a specified fraction of all
    6277             :  *    the tuples expected to be returned by the given relation.
    6278             :  *
    6279             :  * We interpret tuple_fraction the same way as grouping_planner.
    6280             :  *
    6281             :  * We assume set_cheapest() has been run on the given rel.
    6282             :  */
    6283             : Path *
    6284      457310 : get_cheapest_fractional_path(RelOptInfo *rel, double tuple_fraction)
    6285             : {
    6286      457310 :     Path       *best_path = rel->cheapest_total_path;
    6287             :     ListCell   *l;
    6288             : 
    6289             :     /* If all tuples will be retrieved, just return the cheapest-total path */
    6290      457310 :     if (tuple_fraction <= 0.0)
    6291      451806 :         return best_path;
    6292             : 
    6293             :     /* Convert absolute # of tuples to a fraction; no need to clamp to 0..1 */
    6294        5504 :     if (tuple_fraction >= 1.0 && best_path->rows > 0)
    6295        2050 :         tuple_fraction /= best_path->rows;
    6296             : 
    6297       13424 :     foreach(l, rel->pathlist)
    6298             :     {
    6299        7920 :         Path       *path = (Path *) lfirst(l);
    6300             : 
    6301       10336 :         if (path == rel->cheapest_total_path ||
    6302        2416 :             compare_fractional_path_costs(best_path, path, tuple_fraction) <= 0)
    6303        7636 :             continue;
    6304             : 
    6305         284 :         best_path = path;
    6306             :     }
    6307             : 
    6308        5504 :     return best_path;
    6309             : }
    6310             : 
    6311             : /*
    6312             :  * adjust_paths_for_srfs
    6313             :  *      Fix up the Paths of the given upperrel to handle tSRFs properly.
    6314             :  *
    6315             :  * The executor can only handle set-returning functions that appear at the
    6316             :  * top level of the targetlist of a ProjectSet plan node.  If we have any SRFs
    6317             :  * that are not at top level, we need to split up the evaluation into multiple
    6318             :  * plan levels in which each level satisfies this constraint.  This function
    6319             :  * modifies each Path of an upperrel that (might) compute any SRFs in its
    6320             :  * output tlist to insert appropriate projection steps.
    6321             :  *
    6322             :  * The given targets and targets_contain_srfs lists are from
    6323             :  * split_pathtarget_at_srfs().  We assume the existing Paths emit the first
    6324             :  * target in targets.
    6325             :  */
    6326             : static void
    6327        8932 : adjust_paths_for_srfs(PlannerInfo *root, RelOptInfo *rel,
    6328             :                       List *targets, List *targets_contain_srfs)
    6329             : {
    6330             :     ListCell   *lc;
    6331             : 
    6332             :     Assert(list_length(targets) == list_length(targets_contain_srfs));
    6333             :     Assert(!linitial_int(targets_contain_srfs));
    6334             : 
    6335             :     /* If no SRFs appear at this plan level, nothing to do */
    6336        8932 :     if (list_length(targets) == 1)
    6337         592 :         return;
    6338             : 
    6339             :     /*
    6340             :      * Stack SRF-evaluation nodes atop each path for the rel.
    6341             :      *
    6342             :      * In principle we should re-run set_cheapest() here to identify the
    6343             :      * cheapest path, but it seems unlikely that adding the same tlist eval
    6344             :      * costs to all the paths would change that, so we don't bother. Instead,
    6345             :      * just assume that the cheapest-startup and cheapest-total paths remain
    6346             :      * so.  (There should be no parameterized paths anymore, so we needn't
    6347             :      * worry about updating cheapest_parameterized_paths.)
    6348             :      */
    6349       16708 :     foreach(lc, rel->pathlist)
    6350             :     {
    6351        8368 :         Path       *subpath = (Path *) lfirst(lc);
    6352        8368 :         Path       *newpath = subpath;
    6353             :         ListCell   *lc1,
    6354             :                    *lc2;
    6355             : 
    6356             :         Assert(subpath->param_info == NULL);
    6357       26216 :         forboth(lc1, targets, lc2, targets_contain_srfs)
    6358             :         {
    6359       17848 :             PathTarget *thistarget = lfirst_node(PathTarget, lc1);
    6360       17848 :             bool        contains_srfs = (bool) lfirst_int(lc2);
    6361             : 
    6362             :             /* If this level doesn't contain SRFs, do regular projection */
    6363       17848 :             if (contains_srfs)
    6364        8428 :                 newpath = (Path *) create_set_projection_path(root,
    6365             :                                                               rel,
    6366             :                                                               newpath,
    6367             :                                                               thistarget);
    6368             :             else
    6369        9420 :                 newpath = (Path *) apply_projection_to_path(root,
    6370             :                                                             rel,
    6371             :                                                             newpath,
    6372             :                                                             thistarget);
    6373             :         }
    6374        8368 :         lfirst(lc) = newpath;
    6375        8368 :         if (subpath == rel->cheapest_startup_path)
    6376         336 :             rel->cheapest_startup_path = newpath;
    6377        8368 :         if (subpath == rel->cheapest_total_path)
    6378         336 :             rel->cheapest_total_path = newpath;
    6379             :     }
    6380             : 
    6381             :     /* Likewise for partial paths, if any */
    6382        8346 :     foreach(lc, rel->partial_pathlist)
    6383             :     {
    6384           6 :         Path       *subpath = (Path *) lfirst(lc);
    6385           6 :         Path       *newpath = subpath;
    6386             :         ListCell   *lc1,
    6387             :                    *lc2;
    6388             : 
    6389             :         Assert(subpath->param_info == NULL);
    6390          24 :         forboth(lc1, targets, lc2, targets_contain_srfs)
    6391             :         {
    6392          18 :             PathTarget *thistarget = lfirst_node(PathTarget, lc1);
    6393          18 :             bool        contains_srfs = (bool) lfirst_int(lc2);
    6394             : 
    6395             :             /* If this level doesn't contain SRFs, do regular projection */
    6396          18 :             if (contains_srfs)
    6397           6 :                 newpath = (Path *) create_set_projection_path(root,
    6398             :                                                               rel,
    6399             :                                                               newpath,
    6400             :                                                               thistarget);
    6401             :             else
    6402             :             {
    6403             :                 /* avoid apply_projection_to_path, in case of multiple refs */
    6404          12 :                 newpath = (Path *) create_projection_path(root,
    6405             :                                                           rel,
    6406             :                                                           newpath,
    6407             :                                                           thistarget);
    6408             :             }
    6409             :         }
    6410           6 :         lfirst(lc) = newpath;
    6411             :     }
    6412             : }
    6413             : 
    6414             : /*
    6415             :  * expression_planner
    6416             :  *      Perform planner's transformations on a standalone expression.
    6417             :  *
    6418             :  * Various utility commands need to evaluate expressions that are not part
    6419             :  * of a plannable query.  They can do so using the executor's regular
    6420             :  * expression-execution machinery, but first the expression has to be fed
    6421             :  * through here to transform it from parser output to something executable.
    6422             :  *
    6423             :  * Currently, we disallow sublinks in standalone expressions, so there's no
    6424             :  * real "planning" involved here.  (That might not always be true though.)
    6425             :  * What we must do is run eval_const_expressions to ensure that any function
    6426             :  * calls are converted to positional notation and function default arguments
    6427             :  * get inserted.  The fact that constant subexpressions get simplified is a
    6428             :  * side-effect that is useful when the expression will get evaluated more than
    6429             :  * once.  Also, we must fix operator function IDs.
    6430             :  *
    6431             :  * This does not return any information about dependencies of the expression.
    6432             :  * Hence callers should use the results only for the duration of the current
    6433             :  * query.  Callers that would like to cache the results for longer should use
    6434             :  * expression_planner_with_deps, probably via the plancache.
    6435             :  *
    6436             :  * Note: this must not make any damaging changes to the passed-in expression
    6437             :  * tree.  (It would actually be okay to apply fix_opfuncids to it, but since
    6438             :  * we first do an expression_tree_mutator-based walk, what is returned will
    6439             :  * be a new node tree.)  The result is constructed in the current memory
    6440             :  * context; beware that this can leak a lot of additional stuff there, too.
    6441             :  */
    6442             : Expr *
    6443      228188 : expression_planner(Expr *expr)
    6444             : {
    6445             :     Node       *result;
    6446             : 
    6447             :     /*
    6448             :      * Convert named-argument function calls, insert default arguments and
    6449             :      * simplify constant subexprs
    6450             :      */
    6451      228188 :     result = eval_const_expressions(NULL, (Node *) expr);
    6452             : 
    6453             :     /* Fill in opfuncid values if missing */
    6454      228170 :     fix_opfuncids(result);
    6455             : 
    6456      228170 :     return (Expr *) result;
    6457             : }
    6458             : 
    6459             : /*
    6460             :  * expression_planner_with_deps
    6461             :  *      Perform planner's transformations on a standalone expression,
    6462             :  *      returning expression dependency information along with the result.
    6463             :  *
    6464             :  * This is identical to expression_planner() except that it also returns
    6465             :  * information about possible dependencies of the expression, ie identities of
    6466             :  * objects whose definitions affect the result.  As in a PlannedStmt, these
    6467             :  * are expressed as a list of relation Oids and a list of PlanInvalItems.
    6468             :  */
    6469             : Expr *
    6470         348 : expression_planner_with_deps(Expr *expr,
    6471             :                              List **relationOids,
    6472             :                              List **invalItems)
    6473             : {
    6474             :     Node       *result;
    6475             :     PlannerGlobal glob;
    6476             :     PlannerInfo root;
    6477             : 
    6478             :     /* Make up dummy planner state so we can use setrefs machinery */
    6479        6612 :     MemSet(&glob, 0, sizeof(glob));
    6480         348 :     glob.type = T_PlannerGlobal;
    6481         348 :     glob.relationOids = NIL;
    6482         348 :     glob.invalItems = NIL;
    6483             : 
    6484       30624 :     MemSet(&root, 0, sizeof(root));
    6485         348 :     root.type = T_PlannerInfo;
    6486         348 :     root.glob = &glob;
    6487             : 
    6488             :     /*
    6489             :      * Convert named-argument function calls, insert default arguments and
    6490             :      * simplify constant subexprs.  Collect identities of inlined functions
    6491             :      * and elided domains, too.
    6492             :      */
    6493         348 :     result = eval_const_expressions(&root, (Node *) expr);
    6494             : 
    6495             :     /* Fill in opfuncid values if missing */
    6496         348 :     fix_opfuncids(result);
    6497             : 
    6498             :     /*
    6499             :      * Now walk the finished expression to find anything else we ought to
    6500             :      * record as an expression dependency.
    6501             :      */
    6502         348 :     (void) extract_query_dependencies_walker(result, &root);
    6503             : 
    6504         348 :     *relationOids = glob.relationOids;
    6505         348 :     *invalItems = glob.invalItems;
    6506             : 
    6507         348 :     return (Expr *) result;
    6508             : }
    6509             : 
    6510             : 
    6511             : /*
    6512             :  * plan_cluster_use_sort
    6513             :  *      Use the planner to decide how CLUSTER should implement sorting
    6514             :  *
    6515             :  * tableOid is the OID of a table to be clustered on its index indexOid
    6516             :  * (which is already known to be a btree index).  Decide whether it's
    6517             :  * cheaper to do an indexscan or a seqscan-plus-sort to execute the CLUSTER.
    6518             :  * Return true to use sorting, false to use an indexscan.
    6519             :  *
    6520             :  * Note: caller had better already hold some type of lock on the table.
    6521             :  */
    6522             : bool
    6523         190 : plan_cluster_use_sort(Oid tableOid, Oid indexOid)
    6524             : {
    6525             :     PlannerInfo *root;
    6526             :     Query      *query;
    6527             :     PlannerGlobal *glob;
    6528             :     RangeTblEntry *rte;
    6529             :     RelOptInfo *rel;
    6530             :     IndexOptInfo *indexInfo;
    6531             :     QualCost    indexExprCost;
    6532             :     Cost        comparisonCost;
    6533             :     Path       *seqScanPath;
    6534             :     Path        seqScanAndSortPath;
    6535             :     IndexPath  *indexScanPath;
    6536             :     ListCell   *lc;
    6537             : 
    6538             :     /* We can short-circuit the cost comparison if indexscans are disabled */
    6539         190 :     if (!enable_indexscan)
    6540          30 :         return true;            /* use sort */
    6541             : 
    6542             :     /* Set up mostly-dummy planner state */
    6543         160 :     query = makeNode(Query);
    6544         160 :     query->commandType = CMD_SELECT;
    6545             : 
    6546         160 :     glob = makeNode(PlannerGlobal);
    6547             : 
    6548         160 :     root = makeNode(PlannerInfo);
    6549         160 :     root->parse = query;
    6550         160 :     root->glob = glob;
    6551         160 :     root->query_level = 1;
    6552         160 :     root->planner_cxt = CurrentMemoryContext;
    6553         160 :     root->wt_param_id = -1;
    6554         160 :     root->join_domains = list_make1(makeNode(JoinDomain));
    6555             : 
    6556             :     /* Build a minimal RTE for the rel */
    6557         160 :     rte = makeNode(RangeTblEntry);
    6558         160 :     rte->rtekind = RTE_RELATION;
    6559         160 :     rte->relid = tableOid;
    6560         160 :     rte->relkind = RELKIND_RELATION; /* Don't be too picky. */
    6561         160 :     rte->rellockmode = AccessShareLock;
    6562         160 :     rte->lateral = false;
    6563         160 :     rte->inh = false;
    6564         160 :     rte->inFromCl = true;
    6565         160 :     query->rtable = list_make1(rte);
    6566         160 :     addRTEPermissionInfo(&query->rteperminfos, rte);
    6567             : 
    6568             :     /* Set up RTE/RelOptInfo arrays */
    6569         160 :     setup_simple_rel_arrays(root);
    6570             : 
    6571             :     /* Build RelOptInfo */
    6572         160 :     rel = build_simple_rel(root, 1, NULL);
    6573             : 
    6574             :     /* Locate IndexOptInfo for the target index */
    6575         160 :     indexInfo = NULL;
    6576         198 :     foreach(lc, rel->indexlist)
    6577             :     {
    6578         198 :         indexInfo = lfirst_node(IndexOptInfo, lc);
    6579         198 :         if (indexInfo->indexoid == indexOid)
    6580         160 :             break;
    6581             :     }
    6582             : 
    6583             :     /*
    6584             :      * It's possible that get_relation_info did not generate an IndexOptInfo
    6585             :      * for the desired index; this could happen if it's not yet reached its
    6586             :      * indcheckxmin usability horizon, or if it's a system index and we're
    6587             :      * ignoring system indexes.  In such cases we should tell CLUSTER to not
    6588             :      * trust the index contents but use seqscan-and-sort.
    6589             :      */
    6590         160 :     if (lc == NULL)             /* not in the list? */
    6591           0 :         return true;            /* use sort */
    6592             : 
    6593             :     /*
    6594             :      * Rather than doing all the pushups that would be needed to use
    6595             :      * set_baserel_size_estimates, just do a quick hack for rows and width.
    6596             :      */
    6597         160 :     rel->rows = rel->tuples;
    6598         160 :     rel->reltarget->width = get_relation_data_width(tableOid, NULL);
    6599             : 
    6600         160 :     root->total_table_pages = rel->pages;
    6601             : 
    6602             :     /*
    6603             :      * Determine eval cost of the index expressions, if any.  We need to
    6604             :      * charge twice that amount for each tuple comparison that happens during
    6605             :      * the sort, since tuplesort.c will have to re-evaluate the index
    6606             :      * expressions each time.  (XXX that's pretty inefficient...)
    6607             :      */
    6608         160 :     cost_qual_eval(&indexExprCost, indexInfo->indexprs, root);
    6609         160 :     comparisonCost = 2.0 * (indexExprCost.startup + indexExprCost.per_tuple);
    6610             : 
    6611             :     /* Estimate the cost of seq scan + sort */
    6612         160 :     seqScanPath = create_seqscan_path(root, rel, NULL, 0);
    6613         160 :     cost_sort(&seqScanAndSortPath, root, NIL,
    6614         160 :               seqScanPath->total_cost, rel->tuples, rel->reltarget->width,
    6615             :               comparisonCost, maintenance_work_mem, -1.0);
    6616             : 
    6617             :     /* Estimate the cost of index scan */
    6618         160 :     indexScanPath = create_index_path(root, indexInfo,
    6619             :                                       NIL, NIL, NIL, NIL,
    6620             :                                       ForwardScanDirection, false,
    6621             :                                       NULL, 1.0, false);
    6622             : 
    6623         160 :     return (seqScanAndSortPath.total_cost < indexScanPath->path.total_cost);
    6624             : }
    6625             : 
    6626             : /*
    6627             :  * plan_create_index_workers
    6628             :  *      Use the planner to decide how many parallel worker processes
    6629             :  *      CREATE INDEX should request for use
    6630             :  *
    6631             :  * tableOid is the table on which the index is to be built.  indexOid is the
    6632             :  * OID of an index to be created or reindexed (which must be a btree index).
    6633             :  *
    6634             :  * Return value is the number of parallel worker processes to request.  It
    6635             :  * may be unsafe to proceed if this is 0.  Note that this does not include the
    6636             :  * leader participating as a worker (value is always a number of parallel
    6637             :  * worker processes).
    6638             :  *
    6639             :  * Note: caller had better already hold some type of lock on the table and
    6640             :  * index.
    6641             :  */
    6642             : int
    6643       32504 : plan_create_index_workers(Oid tableOid, Oid indexOid)
    6644             : {
    6645             :     PlannerInfo *root;
    6646             :     Query      *query;
    6647             :     PlannerGlobal *glob;
    6648             :     RangeTblEntry *rte;
    6649             :     Relation    heap;
    6650             :     Relation    index;
    6651             :     RelOptInfo *rel;
    6652             :     int         parallel_workers;
    6653             :     BlockNumber heap_blocks;
    6654             :     double      reltuples;
    6655             :     double      allvisfrac;
    6656             : 
    6657             :     /*
    6658             :      * We don't allow performing parallel operation in standalone backend or
    6659             :      * when parallelism is disabled.
    6660             :      */
    6661       32504 :     if (!IsUnderPostmaster || max_parallel_maintenance_workers == 0)
    6662         424 :         return 0;
    6663             : 
    6664             :     /* Set up largely-dummy planner state */
    6665       32080 :     query = makeNode(Query);
    6666       32080 :     query->commandType = CMD_SELECT;
    6667             : 
    6668       32080 :     glob = makeNode(PlannerGlobal);
    6669             : 
    6670       32080 :     root = makeNode(PlannerInfo);
    6671       32080 :     root->parse = query;
    6672       32080 :     root->glob = glob;
    6673       32080 :     root->query_level = 1;
    6674       32080 :     root->planner_cxt = CurrentMemoryContext;
    6675       32080 :     root->wt_param_id = -1;
    6676       32080 :     root->join_domains = list_make1(makeNode(JoinDomain));
    6677             : 
    6678             :     /*
    6679             :      * Build a minimal RTE.
    6680             :      *
    6681             :      * Mark the RTE with inh = true.  This is a kludge to prevent
    6682             :      * get_relation_info() from fetching index info, which is necessary
    6683             :      * because it does not expect that any IndexOptInfo is currently
    6684             :      * undergoing REINDEX.
    6685             :      */
    6686       32080 :     rte = makeNode(RangeTblEntry);
    6687       32080 :     rte->rtekind = RTE_RELATION;
    6688       32080 :     rte->relid = tableOid;
    6689       32080 :     rte->relkind = RELKIND_RELATION; /* Don't be too picky. */
    6690       32080 :     rte->rellockmode = AccessShareLock;
    6691       32080 :     rte->lateral = false;
    6692       32080 :     rte->inh = true;
    6693       32080 :     rte->inFromCl = true;
    6694       32080 :     query->rtable = list_make1(rte);
    6695       32080 :     addRTEPermissionInfo(&query->rteperminfos, rte);
    6696             : 
    6697             :     /* Set up RTE/RelOptInfo arrays */
    6698       32080 :     setup_simple_rel_arrays(root);
    6699             : 
    6700             :     /* Build RelOptInfo */
    6701       32080 :     rel = build_simple_rel(root, 1, NULL);
    6702             : 
    6703             :     /* Rels are assumed already locked by the caller */
    6704       32080 :     heap = table_open(tableOid, NoLock);
    6705       32080 :     index = index_open(indexOid, NoLock);
    6706             : 
    6707             :     /*
    6708             :      * Determine if it's safe to proceed.
    6709             :      *
    6710             :      * Currently, parallel workers can't access the leader's temporary tables.
    6711             :      * Furthermore, any index predicate or index expressions must be parallel
    6712             :      * safe.
    6713             :      */
    6714       32080 :     if (heap->rd_rel->relpersistence == RELPERSISTENCE_TEMP ||
    6715       30254 :         !is_parallel_safe(root, (Node *) RelationGetIndexExpressions(index)) ||
    6716       30134 :         !is_parallel_safe(root, (Node *) RelationGetIndexPredicate(index)))
    6717             :     {
    6718        1946 :         parallel_workers = 0;
    6719        1946 :         goto done;
    6720             :     }
    6721             : 
    6722             :     /*
    6723             :      * If parallel_workers storage parameter is set for the table, accept that
    6724             :      * as the number of parallel worker processes to launch (though still cap
    6725             :      * at max_parallel_maintenance_workers).  Note that we deliberately do not
    6726             :      * consider any other factor when parallel_workers is set. (e.g., memory
    6727             :      * use by workers.)
    6728             :      */
    6729       30134 :     if (rel->rel_parallel_workers != -1)
    6730             :     {
    6731          14 :         parallel_workers = Min(rel->rel_parallel_workers,
    6732             :                                max_parallel_maintenance_workers);
    6733          14 :         goto done;
    6734             :     }
    6735             : 
    6736             :     /*
    6737             :      * Estimate heap relation size ourselves, since rel->pages cannot be
    6738             :      * trusted (heap RTE was marked as inheritance parent)
    6739             :      */
    6740       30120 :     estimate_rel_size(heap, NULL, &heap_blocks, &reltuples, &allvisfrac);
    6741             : 
    6742             :     /*
    6743             :      * Determine number of workers to scan the heap relation using generic
    6744             :      * model
    6745             :      */
    6746       30120 :     parallel_workers = compute_parallel_worker(rel, heap_blocks, -1,
    6747             :                                                max_parallel_maintenance_workers);
    6748             : 
    6749             :     /*
    6750             :      * Cap workers based on available maintenance_work_mem as needed.
    6751             :      *
    6752             :      * Note that each tuplesort participant receives an even share of the
    6753             :      * total maintenance_work_mem budget.  Aim to leave participants
    6754             :      * (including the leader as a participant) with no less than 32MB of
    6755             :      * memory.  This leaves cases where maintenance_work_mem is set to 64MB
    6756             :      * immediately past the threshold of being capable of launching a single
    6757             :      * parallel worker to sort.
    6758             :      */
    6759       30248 :     while (parallel_workers > 0 &&
    6760         270 :            maintenance_work_mem / (parallel_workers + 1) < 32768L)
    6761         128 :         parallel_workers--;
    6762             : 
    6763       30120 : done:
    6764       32080 :     index_close(index, NoLock);
    6765       32080 :     table_close(heap, NoLock);
    6766             : 
    6767       32080 :     return parallel_workers;
    6768             : }
    6769             : 
    6770             : /*
    6771             :  * make_ordered_path
    6772             :  *      Return a path ordered by 'pathkeys' based on the given 'path'.  May
    6773             :  *      return NULL if it doesn't make sense to generate an ordered path in
    6774             :  *      this case.
    6775             :  */
    6776             : static Path *
    6777       42042 : make_ordered_path(PlannerInfo *root, RelOptInfo *rel, Path *path,
    6778             :                   Path *cheapest_path, List *pathkeys)
    6779             : {
    6780             :     bool        is_sorted;
    6781             :     int         presorted_keys;
    6782             : 
    6783       42042 :     is_sorted = pathkeys_count_contained_in(pathkeys,
    6784             :                                             path->pathkeys,
    6785             :                                             &presorted_keys);
    6786             : 
    6787       42042 :     if (!is_sorted)
    6788             :     {
    6789             :         /*
    6790             :          * Try at least sorting the cheapest path and also try incrementally
    6791             :          * sorting any path which is partially sorted already (no need to deal
    6792             :          * with paths which have presorted keys when incremental sort is
    6793             :          * disabled unless it's the cheapest input path).
    6794             :          */
    6795        8148 :         if (path != cheapest_path &&
    6796         632 :             (presorted_keys == 0 || !enable_incremental_sort))
    6797         428 :             return NULL;
    6798             : 
    6799             :         /*
    6800             :          * We've no need to consider both a sort and incremental sort. We'll
    6801             :          * just do a sort if there are no presorted keys and an incremental
    6802             :          * sort when there are presorted keys.
    6803             :          */
    6804        7720 :         if (presorted_keys == 0 || !enable_incremental_sort)
    6805        7444 :             path = (Path *) create_sort_path(root,
    6806             :                                              rel,
    6807             :                                              path,
    6808             :                                              pathkeys,
    6809             :                                              -1.0);
    6810             :         else
    6811         276 :             path = (Path *) create_incremental_sort_path(root,
    6812             :                                                          rel,
    6813             :                                                          path,
    6814             :                                                          pathkeys,
    6815             :                                                          presorted_keys,
    6816             :                                                          -1.0);
    6817             :     }
    6818             : 
    6819       41614 :     return path;
    6820             : }
    6821             : 
    6822             : /*
    6823             :  * add_paths_to_grouping_rel
    6824             :  *
    6825             :  * Add non-partial paths to grouping relation.
    6826             :  */
    6827             : static void
    6828       34812 : add_paths_to_grouping_rel(PlannerInfo *root, RelOptInfo *input_rel,
    6829             :                           RelOptInfo *grouped_rel,
    6830             :                           RelOptInfo *partially_grouped_rel,
    6831             :                           const AggClauseCosts *agg_costs,
    6832             :                           grouping_sets_data *gd, double dNumGroups,
    6833             :                           GroupPathExtraData *extra)
    6834             : {
    6835       34812 :     Query      *parse = root->parse;
    6836       34812 :     Path       *cheapest_path = input_rel->cheapest_total_path;
    6837             :     ListCell   *lc;
    6838       34812 :     bool        can_hash = (extra->flags & GROUPING_CAN_USE_HASH) != 0;
    6839       34812 :     bool        can_sort = (extra->flags & GROUPING_CAN_USE_SORT) != 0;
    6840       34812 :     List       *havingQual = (List *) extra->havingQual;
    6841       34812 :     AggClauseCosts *agg_final_costs = &extra->agg_final_costs;
    6842             : 
    6843       34812 :     if (can_sort)
    6844             :     {
    6845             :         /*
    6846             :          * Use any available suitably-sorted path as input, and also consider
    6847             :          * sorting the cheapest-total path and incremental sort on any paths
    6848             :          * with presorted keys.
    6849             :          */
    6850       72000 :         foreach(lc, input_rel->pathlist)
    6851             :         {
    6852             :             ListCell   *lc2;
    6853       37194 :             Path       *path = (Path *) lfirst(lc);
    6854       37194 :             Path       *path_save = path;
    6855       37194 :             List       *pathkey_orderings = NIL;
    6856             : 
    6857             :             /* generate alternative group orderings that might be useful */
    6858       37194 :             pathkey_orderings = get_useful_group_keys_orderings(root, path);
    6859             : 
    6860             :             Assert(list_length(pathkey_orderings) > 0);
    6861             : 
    6862       74514 :             foreach(lc2, pathkey_orderings)
    6863             :             {
    6864       37320 :                 PathKeyInfo *info = (PathKeyInfo *) lfirst(lc2);
    6865             : 
    6866             :                 /* restore the path (we replace it in the loop) */
    6867       37320 :                 path = path_save;
    6868             : 
    6869       37320 :                 path = make_ordered_path(root,
    6870             :                                          grouped_rel,
    6871             :                                          path,
    6872             :                                          cheapest_path,
    6873             :                                          info->pathkeys);
    6874       37320 :                 if (path == NULL)
    6875         326 :                     continue;
    6876             : 
    6877             :                 /* Now decide what to stick atop it */
    6878       36994 :                 if (parse->groupingSets)
    6879             :                 {
    6880         794 :                     consider_groupingsets_paths(root, grouped_rel,
    6881             :                                                 path, true, can_hash,
    6882             :                                                 gd, agg_costs, dNumGroups);
    6883             :                 }
    6884       36200 :                 else if (parse->hasAggs)
    6885             :                 {
    6886             :                     /*
    6887             :                      * We have aggregation, possibly with plain GROUP BY. Make
    6888             :                      * an AggPath.
    6889             :                      */
    6890       35554 :                     add_path(grouped_rel, (Path *)
    6891       35554 :                              create_agg_path(root,
    6892             :                                              grouped_rel,
    6893             :                                              path,
    6894       35554 :                                              grouped_rel->reltarget,
    6895       35554 :                                              parse->groupClause ? AGG_SORTED : AGG_PLAIN,
    6896             :                                              AGGSPLIT_SIMPLE,
    6897             :                                              info->clauses,
    6898             :                                              havingQual,
    6899             :                                              agg_costs,
    6900             :                                              dNumGroups));
    6901             :                 }
    6902         646 :                 else if (parse->groupClause)
    6903             :                 {
    6904             :                     /*
    6905             :                      * We have GROUP BY without aggregation or grouping sets.
    6906             :                      * Make a GroupPath.
    6907             :                      */
    6908         646 :                     add_path(grouped_rel, (Path *)
    6909         646 :                              create_group_path(root,
    6910             :                                                grouped_rel,
    6911             :                                                path,
    6912             :                                                info->clauses,
    6913             :                                                havingQual,
    6914             :                                                dNumGroups));
    6915             :                 }
    6916             :                 else
    6917             :                 {
    6918             :                     /* Other cases should have been handled above */
    6919             :                     Assert(false);
    6920             :                 }
    6921             :             }
    6922             :         }
    6923             : 
    6924             :         /*
    6925             :          * Instead of operating directly on the input relation, we can
    6926             :          * consider finalizing a partially aggregated path.
    6927             :          */
    6928       34806 :         if (partially_grouped_rel != NULL)
    6929             :         {
    6930        3866 :             foreach(lc, partially_grouped_rel->pathlist)
    6931             :             {
    6932             :                 ListCell   *lc2;
    6933        2312 :                 Path       *path = (Path *) lfirst(lc);
    6934        2312 :                 Path       *path_save = path;
    6935        2312 :                 List       *pathkey_orderings = NIL;
    6936             : 
    6937             :                 /* generate alternative group orderings that might be useful */
    6938        2312 :                 pathkey_orderings = get_useful_group_keys_orderings(root, path);
    6939             : 
    6940             :                 Assert(list_length(pathkey_orderings) > 0);
    6941             : 
    6942             :                 /* process all potentially interesting grouping reorderings */
    6943        4624 :                 foreach(lc2, pathkey_orderings)
    6944             :                 {
    6945        2312 :                     PathKeyInfo *info = (PathKeyInfo *) lfirst(lc2);
    6946             : 
    6947             :                     /* restore the path (we replace it in the loop) */
    6948        2312 :                     path = path_save;
    6949             : 
    6950        2312 :                     path = make_ordered_path(root,
    6951             :                                              grouped_rel,
    6952             :                                              path,
    6953        2312 :                                              partially_grouped_rel->cheapest_total_path,
    6954             :                                              info->pathkeys);
    6955             : 
    6956        2312 :                     if (path == NULL)
    6957          96 :                         continue;
    6958             : 
    6959        2216 :                     if (parse->hasAggs)
    6960        1968 :                         add_path(grouped_rel, (Path *)
    6961        1968 :                                  create_agg_path(root,
    6962             :                                                  grouped_rel,
    6963             :                                                  path,
    6964        1968 :                                                  grouped_rel->reltarget,
    6965        1968 :                                                  parse->groupClause ? AGG_SORTED : AGG_PLAIN,
    6966             :                                                  AGGSPLIT_FINAL_DESERIAL,
    6967             :                                                  info->clauses,
    6968             :                                                  havingQual,
    6969             :                                                  agg_final_costs,
    6970             :                                                  dNumGroups));
    6971             :                     else
    6972         248 :                         add_path(grouped_rel, (Path *)
    6973         248 :                                  create_group_path(root,
    6974             :                                                    grouped_rel,
    6975             :                                                    path,
    6976             :                                                    info->clauses,
    6977             :                                                    havingQual,
    6978             :                                                    dNumGroups));
    6979             : 
    6980             :                 }
    6981             :             }
    6982             :         }
    6983             :     }
    6984             : 
    6985       34812 :     if (can_hash)
    6986             :     {
    6987        4506 :         if (parse->groupingSets)
    6988             :         {
    6989             :             /*
    6990             :              * Try for a hash-only groupingsets path over unsorted input.
    6991             :              */
    6992         650 :             consider_groupingsets_paths(root, grouped_rel,
    6993             :                                         cheapest_path, false, true,
    6994             :                                         gd, agg_costs, dNumGroups);
    6995             :         }
    6996             :         else
    6997             :         {
    6998             :             /*
    6999             :              * Generate a HashAgg Path.  We just need an Agg over the
    7000             :              * cheapest-total input path, since input order won't matter.
    7001             :              */
    7002        3856 :             add_path(grouped_rel, (Path *)
    7003        3856 :                      create_agg_path(root, grouped_rel,
    7004             :                                      cheapest_path,
    7005        3856 :                                      grouped_rel->reltarget,
    7006             :                                      AGG_HASHED,
    7007             :                                      AGGSPLIT_SIMPLE,
    7008             :                                      root->processed_groupClause,
    7009             :                                      havingQual,
    7010             :                                      agg_costs,
    7011             :                                      dNumGroups));
    7012             :         }
    7013             : 
    7014             :         /*
    7015             :          * Generate a Finalize HashAgg Path atop of the cheapest partially
    7016             :          * grouped path, assuming there is one
    7017             :          */
    7018        4506 :         if (partially_grouped_rel && partially_grouped_rel->pathlist)
    7019             :         {
    7020         766 :             Path       *path = partially_grouped_rel->cheapest_total_path;
    7021             : 
    7022         766 :             add_path(grouped_rel, (Path *)
    7023         766 :                      create_agg_path(root,
    7024             :                                      grouped_rel,
    7025             :                                      path,
    7026         766 :                                      grouped_rel->reltarget,
    7027             :                                      AGG_HASHED,
    7028             :                                      AGGSPLIT_FINAL_DESERIAL,
    7029             :                                      root->processed_groupClause,
    7030             :                                      havingQual,
    7031             :                                      agg_final_costs,
    7032             :                                      dNumGroups));
    7033             :         }
    7034             :     }
    7035             : 
    7036             :     /*
    7037             :      * When partitionwise aggregate is used, we might have fully aggregated
    7038             :      * paths in the partial pathlist, because add_paths_to_append_rel() will
    7039             :      * consider a path for grouped_rel consisting of a Parallel Append of
    7040             :      * non-partial paths from each child.
    7041             :      */
    7042       34812 :     if (grouped_rel->partial_pathlist != NIL)
    7043         162 :         gather_grouping_paths(root, grouped_rel);
    7044       34812 : }
    7045             : 
    7046             : /*
    7047             :  * create_partial_grouping_paths
    7048             :  *
    7049             :  * Create a new upper relation representing the result of partial aggregation
    7050             :  * and populate it with appropriate paths.  Note that we don't finalize the
    7051             :  * lists of paths here, so the caller can add additional partial or non-partial
    7052             :  * paths and must afterward call gather_grouping_paths and set_cheapest on
    7053             :  * the returned upper relation.
    7054             :  *
    7055             :  * All paths for this new upper relation -- both partial and non-partial --
    7056             :  * have been partially aggregated but require a subsequent FinalizeAggregate
    7057             :  * step.
    7058             :  *
    7059             :  * NB: This function is allowed to return NULL if it determines that there is
    7060             :  * no real need to create a new RelOptInfo.
    7061             :  */
    7062             : static RelOptInfo *
    7063       31628 : create_partial_grouping_paths(PlannerInfo *root,
    7064             :                               RelOptInfo *grouped_rel,
    7065             :                               RelOptInfo *input_rel,
    7066             :                               grouping_sets_data *gd,
    7067             :                               GroupPathExtraData *extra,
    7068             :                               bool force_rel_creation)
    7069             : {
    7070       31628 :     Query      *parse = root->parse;
    7071             :     RelOptInfo *partially_grouped_rel;
    7072       31628 :     AggClauseCosts *agg_partial_costs = &extra->agg_partial_costs;
    7073       31628 :     AggClauseCosts *agg_final_costs = &extra->agg_final_costs;
    7074       31628 :     Path       *cheapest_partial_path = NULL;
    7075       31628 :     Path       *cheapest_total_path = NULL;
    7076       31628 :     double      dNumPartialGroups = 0;
    7077       31628 :     double      dNumPartialPartialGroups = 0;
    7078             :     ListCell   *lc;
    7079       31628 :     bool        can_hash = (extra->flags & GROUPING_CAN_USE_HASH) != 0;
    7080       31628 :     bool        can_sort = (extra->flags & GROUPING_CAN_USE_SORT) != 0;
    7081             : 
    7082             :     /*
    7083             :      * Consider whether we should generate partially aggregated non-partial
    7084             :      * paths.  We can only do this if we have a non-partial path, and only if
    7085             :      * the parent of the input rel is performing partial partitionwise
    7086             :      * aggregation.  (Note that extra->patype is the type of partitionwise
    7087             :      * aggregation being used at the parent level, not this level.)
    7088             :      */
    7089       31628 :     if (input_rel->pathlist != NIL &&
    7090       31628 :         extra->patype == PARTITIONWISE_AGGREGATE_PARTIAL)
    7091         594 :         cheapest_total_path = input_rel->cheapest_total_path;
    7092             : 
    7093             :     /*
    7094             :      * If parallelism is possible for grouped_rel, then we should consider
    7095             :      * generating partially-grouped partial paths.  However, if the input rel
    7096             :      * has no partial paths, then we can't.
    7097             :      */
    7098       31628 :     if (grouped_rel->consider_parallel && input_rel->partial_pathlist != NIL)
    7099        1804 :         cheapest_partial_path = linitial(input_rel->partial_pathlist);
    7100             : 
    7101             :     /*
    7102             :      * If we can't partially aggregate partial paths, and we can't partially
    7103             :      * aggregate non-partial paths, then don't bother creating the new
    7104             :      * RelOptInfo at all, unless the caller specified force_rel_creation.
    7105             :      */
    7106       31628 :     if (cheapest_total_path == NULL &&
    7107       29566 :         cheapest_partial_path == NULL &&
    7108       29566 :         !force_rel_creation)
    7109       29480 :         return NULL;
    7110             : 
    7111             :     /*
    7112             :      * Build a new upper relation to represent the result of partially
    7113             :      * aggregating the rows from the input relation.
    7114             :      */
    7115        2148 :     partially_grouped_rel = fetch_upper_rel(root,
    7116             :                                             UPPERREL_PARTIAL_GROUP_AGG,
    7117             :                                             grouped_rel->relids);
    7118        2148 :     partially_grouped_rel->consider_parallel =
    7119        2148 :         grouped_rel->consider_parallel;
    7120        2148 :     partially_grouped_rel->reloptkind = grouped_rel->reloptkind;
    7121        2148 :     partially_grouped_rel->serverid = grouped_rel->serverid;
    7122        2148 :     partially_grouped_rel->userid = grouped_rel->userid;
    7123        2148 :     partially_grouped_rel->useridiscurrent = grouped_rel->useridiscurrent;
    7124        2148 :     partially_grouped_rel->fdwroutine = grouped_rel->fdwroutine;
    7125             : 
    7126             :     /*
    7127             :      * Build target list for partial aggregate paths.  These paths cannot just
    7128             :      * emit the same tlist as regular aggregate paths, because (1) we must
    7129             :      * include Vars and Aggrefs needed in HAVING, which might not appear in
    7130             :      * the result tlist, and (2) the Aggrefs must be set in partial mode.
    7131             :      */
    7132        2148 :     partially_grouped_rel->reltarget =
    7133        2148 :         make_partial_grouping_target(root, grouped_rel->reltarget,
    7134             :                                      extra->havingQual);
    7135             : 
    7136        2148 :     if (!extra->partial_costs_set)
    7137             :     {
    7138             :         /*
    7139             :          * Collect statistics about aggregates for estimating costs of
    7140             :          * performing aggregation in parallel.
    7141             :          */
    7142        7596 :         MemSet(agg_partial_costs, 0, sizeof(AggClauseCosts));
    7143        7596 :         MemSet(agg_final_costs, 0, sizeof(AggClauseCosts));
    7144        1266 :         if (parse->hasAggs)
    7145             :         {
    7146             :             /* partial phase */
    7147        1138 :             get_agg_clause_costs(root, AGGSPLIT_INITIAL_SERIAL,
    7148             :                                  agg_partial_costs);
    7149             : 
    7150             :             /* final phase */
    7151        1138 :             get_agg_clause_costs(root, AGGSPLIT_FINAL_DESERIAL,
    7152             :                                  agg_final_costs);
    7153             :         }
    7154             : 
    7155        1266 :         extra->partial_costs_set = true;
    7156             :     }
    7157             : 
    7158             :     /* Estimate number of partial groups. */
    7159        2148 :     if (cheapest_total_path != NULL)
    7160             :         dNumPartialGroups =
    7161         594 :             get_number_of_groups(root,
    7162             :                                  cheapest_total_path->rows,
    7163             :                                  gd,
    7164             :                                  extra->targetList);
    7165        2148 :     if (cheapest_partial_path != NULL)
    7166             :         dNumPartialPartialGroups =
    7167        1804 :             get_number_of_groups(root,
    7168             :                                  cheapest_partial_path->rows,
    7169             :                                  gd,
    7170             :                                  extra->targetList);
    7171             : 
    7172        2148 :     if (can_sort && cheapest_total_path != NULL)
    7173             :     {
    7174             :         /* This should have been checked previously */
    7175             :         Assert(parse->hasAggs || parse->groupClause);
    7176             : 
    7177             :         /*
    7178             :          * Use any available suitably-sorted path as input, and also consider
    7179             :          * sorting the cheapest partial path.
    7180             :          */
    7181        1188 :         foreach(lc, input_rel->pathlist)
    7182             :         {
    7183             :             ListCell   *lc2;
    7184         594 :             Path       *path = (Path *) lfirst(lc);
    7185         594 :             Path       *path_save = path;
    7186         594 :             List       *pathkey_orderings = NIL;
    7187             : 
    7188             :             /* generate alternative group orderings that might be useful */
    7189         594 :             pathkey_orderings = get_useful_group_keys_orderings(root, path);
    7190             : 
    7191             :             Assert(list_length(pathkey_orderings) > 0);
    7192             : 
    7193             :             /* process all potentially interesting grouping reorderings */
    7194        1188 :             foreach(lc2, pathkey_orderings)
    7195             :             {
    7196         594 :                 PathKeyInfo *info = (PathKeyInfo *) lfirst(lc2);
    7197             : 
    7198             :                 /* restore the path (we replace it in the loop) */
    7199         594 :                 path = path_save;
    7200             : 
    7201         594 :                 path = make_ordered_path(root,
    7202             :                                          partially_grouped_rel,
    7203             :                                          path,
    7204             :                                          cheapest_total_path,
    7205             :                                          info->pathkeys);
    7206             : 
    7207         594 :                 if (path == NULL)
    7208           0 :                     continue;
    7209             : 
    7210         594 :                 if (parse->hasAggs)
    7211         522 :                     add_path(partially_grouped_rel, (Path *)
    7212         522 :                              create_agg_path(root,
    7213             :                                              partially_grouped_rel,
    7214             :                                              path,
    7215         522 :                                              partially_grouped_rel->reltarget,
    7216         522 :                                              parse->groupClause ? AGG_SORTED : AGG_PLAIN,
    7217             :                                              AGGSPLIT_INITIAL_SERIAL,
    7218             :                                              info->clauses,
    7219             :                                              NIL,
    7220             :                                              agg_partial_costs,
    7221             :                                              dNumPartialGroups));
    7222             :                 else
    7223          72 :                     add_path(partially_grouped_rel, (Path *)
    7224          72 :                              create_group_path(root,
    7225             :                                                partially_grouped_rel,
    7226             :                                                path,
    7227             :                                                info->clauses,
    7228             :                                                NIL,
    7229             :                                                dNumPartialGroups));
    7230             :             }
    7231             :         }
    7232             :     }
    7233             : 
    7234        2148 :     if (can_sort && cheapest_partial_path != NULL)
    7235             :     {
    7236             :         /* Similar to above logic, but for partial paths. */
    7237        3620 :         foreach(lc, input_rel->partial_pathlist)
    7238             :         {
    7239             :             ListCell   *lc2;
    7240        1816 :             Path       *path = (Path *) lfirst(lc);
    7241        1816 :             Path       *path_save = path;
    7242        1816 :             List       *pathkey_orderings = NIL;
    7243             : 
    7244             :             /* generate alternative group orderings that might be useful */
    7245        1816 :             pathkey_orderings = get_useful_group_keys_orderings(root, path);
    7246             : 
    7247             :             Assert(list_length(pathkey_orderings) > 0);
    7248             : 
    7249             :             /* process all potentially interesting grouping reorderings */
    7250        3632 :             foreach(lc2, pathkey_orderings)
    7251             :             {
    7252        1816 :                 PathKeyInfo *info = (PathKeyInfo *) lfirst(lc2);
    7253             : 
    7254             : 
    7255             :                 /* restore the path (we replace it in the loop) */
    7256        1816 :                 path = path_save;
    7257             : 
    7258        1816 :                 path = make_ordered_path(root,
    7259             :                                          partially_grouped_rel,
    7260             :                                          path,
    7261             :                                          cheapest_partial_path,
    7262             :                                          info->pathkeys);
    7263             : 
    7264        1816 :                 if (path == NULL)
    7265           6 :                     continue;
    7266             : 
    7267        1810 :                 if (parse->hasAggs)
    7268        1658 :                     add_partial_path(partially_grouped_rel, (Path *)
    7269        1658 :                                      create_agg_path(root,
    7270             :                                                      partially_grouped_rel,
    7271             :                                                      path,
    7272        1658 :                                                      partially_grouped_rel->reltarget,
    7273        1658 :                                                      parse->groupClause ? AGG_SORTED : AGG_PLAIN,
    7274             :                                                      AGGSPLIT_INITIAL_SERIAL,
    7275             :                                                      info->clauses,
    7276             :                                                      NIL,
    7277             :                                                      agg_partial_costs,
    7278             :                                                      dNumPartialPartialGroups));
    7279             :                 else
    7280         152 :                     add_partial_path(partially_grouped_rel, (Path *)
    7281         152 :                                      create_group_path(root,
    7282             :                                                        partially_grouped_rel,
    7283             :                                                        path,
    7284             :                                                        info->clauses,
    7285             :                                                        NIL,
    7286             :                                                        dNumPartialPartialGroups));
    7287             :             }
    7288             :         }
    7289             :     }
    7290             : 
    7291             :     /*
    7292             :      * Add a partially-grouped HashAgg Path where possible
    7293             :      */
    7294        2148 :     if (can_hash && cheapest_total_path != NULL)
    7295             :     {
    7296             :         /* Checked above */
    7297             :         Assert(parse->hasAggs || parse->groupClause);
    7298             : 
    7299         594 :         add_path(partially_grouped_rel, (Path *)
    7300         594 :                  create_agg_path(root,
    7301             :                                  partially_grouped_rel,
    7302             :                                  cheapest_total_path,
    7303         594 :                                  partially_grouped_rel->reltarget,
    7304             :                                  AGG_HASHED,
    7305             :                                  AGGSPLIT_INITIAL_SERIAL,
    7306             :                                  root->processed_groupClause,
    7307             :                                  NIL,
    7308             :                                  agg_partial_costs,
    7309             :                                  dNumPartialGroups));
    7310             :     }
    7311             : 
    7312             :     /*
    7313             :      * Now add a partially-grouped HashAgg partial Path where possible
    7314             :      */
    7315        2148 :     if (can_hash && cheapest_partial_path != NULL)
    7316             :     {
    7317        1016 :         add_partial_path(partially_grouped_rel, (Path *)
    7318        1016 :                          create_agg_path(root,
    7319             :                                          partially_grouped_rel,
    7320             :                                          cheapest_partial_path,
    7321        1016 :                                          partially_grouped_rel->reltarget,
    7322             :                                          AGG_HASHED,
    7323             :                                          AGGSPLIT_INITIAL_SERIAL,
    7324             :                                          root->processed_groupClause,
    7325             :                                          NIL,
    7326             :                                          agg_partial_costs,
    7327             :                                          dNumPartialPartialGroups));
    7328             :     }
    7329             : 
    7330             :     /*
    7331             :      * If there is an FDW that's responsible for all baserels of the query,
    7332             :      * let it consider adding partially grouped ForeignPaths.
    7333             :      */
    7334        2148 :     if (partially_grouped_rel->fdwroutine &&
    7335           6 :         partially_grouped_rel->fdwroutine->GetForeignUpperPaths)
    7336             :     {
    7337           6 :         FdwRoutine *fdwroutine = partially_grouped_rel->fdwroutine;
    7338             : 
    7339           6 :         fdwroutine->GetForeignUpperPaths(root,
    7340             :                                          UPPERREL_PARTIAL_GROUP_AGG,
    7341             :                                          input_rel, partially_grouped_rel,
    7342             :                                          extra);
    7343             :     }
    7344             : 
    7345        2148 :     return partially_grouped_rel;
    7346             : }
    7347             : 
    7348             : /*
    7349             :  * Generate Gather and Gather Merge paths for a grouping relation or partial
    7350             :  * grouping relation.
    7351             :  *
    7352             :  * generate_useful_gather_paths does most of the work, but we also consider a
    7353             :  * special case: we could try sorting the data by the group_pathkeys and then
    7354             :  * applying Gather Merge.
    7355             :  *
    7356             :  * NB: This function shouldn't be used for anything other than a grouped or
    7357             :  * partially grouped relation not only because of the fact that it explicitly
    7358             :  * references group_pathkeys but we pass "true" as the third argument to
    7359             :  * generate_useful_gather_paths().
    7360             :  */
    7361             : static void
    7362        1630 : gather_grouping_paths(PlannerInfo *root, RelOptInfo *rel)
    7363             : {
    7364             :     ListCell   *lc;
    7365             :     Path       *cheapest_partial_path;
    7366             :     List       *groupby_pathkeys;
    7367             : 
    7368             :     /*
    7369             :      * This occurs after any partial aggregation has taken place, so trim off
    7370             :      * any pathkeys added for ORDER BY / DISTINCT aggregates.
    7371             :      */
    7372        1630 :     if (list_length(root->group_pathkeys) > root->num_groupby_pathkeys)
    7373          18 :         groupby_pathkeys = list_copy_head(root->group_pathkeys,
    7374             :                                           root->num_groupby_pathkeys);
    7375             :     else
    7376        1612 :         groupby_pathkeys = root->group_pathkeys;
    7377             : 
    7378             :     /* Try Gather for unordered paths and Gather Merge for ordered ones. */
    7379        1630 :     generate_useful_gather_paths(root, rel, true);
    7380             : 
    7381        1630 :     cheapest_partial_path = linitial(rel->partial_pathlist);
    7382             : 
    7383             :     /* XXX Shouldn't this also consider the group-key-reordering? */
    7384        3872 :     foreach(lc, rel->partial_pathlist)
    7385             :     {
    7386        2242 :         Path       *path = (Path *) lfirst(lc);
    7387             :         bool        is_sorted;
    7388             :         int         presorted_keys;
    7389             :         double      total_groups;
    7390             : 
    7391        2242 :         is_sorted = pathkeys_count_contained_in(groupby_pathkeys,
    7392             :                                                 path->pathkeys,
    7393             :                                                 &presorted_keys);
    7394             : 
    7395        2242 :         if (is_sorted)
    7396        1468 :             continue;
    7397             : 
    7398             :         /*
    7399             :          * Try at least sorting the cheapest path and also try incrementally
    7400             :          * sorting any path which is partially sorted already (no need to deal
    7401             :          * with paths which have presorted keys when incremental sort is
    7402             :          * disabled unless it's the cheapest input path).
    7403             :          */
    7404         774 :         if (path != cheapest_partial_path &&
    7405           0 :             (presorted_keys == 0 || !enable_incremental_sort))
    7406           0 :             continue;
    7407             : 
    7408         774 :         total_groups = path->rows * path->parallel_workers;
    7409             : 
    7410             :         /*
    7411             :          * We've no need to consider both a sort and incremental sort. We'll
    7412             :          * just do a sort if there are no presorted keys and an incremental
    7413             :          * sort when there are presorted keys.
    7414             :          */
    7415         774 :         if (presorted_keys == 0 || !enable_incremental_sort)
    7416         774 :             path = (Path *) create_sort_path(root, rel, path,
    7417             :                                              groupby_pathkeys,
    7418             :                                              -1.0);
    7419             :         else
    7420           0 :             path = (Path *) create_incremental_sort_path(root,
    7421             :                                                          rel,
    7422             :                                                          path,
    7423             :                                                          groupby_pathkeys,
    7424             :                                                          presorted_keys,
    7425             :                                                          -1.0);
    7426             : 
    7427             :         path = (Path *)
    7428         774 :             create_gather_merge_path(root,
    7429             :                                      rel,
    7430             :                                      path,
    7431         774 :                                      rel->reltarget,
    7432             :                                      groupby_pathkeys,
    7433             :                                      NULL,
    7434             :                                      &total_groups);
    7435             : 
    7436         774 :         add_path(rel, path);
    7437             :     }
    7438        1630 : }
    7439             : 
    7440             : /*
    7441             :  * can_partial_agg
    7442             :  *
    7443             :  * Determines whether or not partial grouping and/or aggregation is possible.
    7444             :  * Returns true when possible, false otherwise.
    7445             :  */
    7446             : static bool
    7447       34008 : can_partial_agg(PlannerInfo *root)
    7448             : {
    7449       34008 :     Query      *parse = root->parse;
    7450             : 
    7451       34008 :     if (!parse->hasAggs && parse->groupClause == NIL)
    7452             :     {
    7453             :         /*
    7454             :          * We don't know how to do parallel aggregation unless we have either
    7455             :          * some aggregates or a grouping clause.
    7456             :          */
    7457           0 :         return false;
    7458             :     }
    7459       34008 :     else if (parse->groupingSets)
    7460             :     {
    7461             :         /* We don't know how to do grouping sets in parallel. */
    7462         728 :         return false;
    7463             :     }
    7464       33280 :     else if (root->hasNonPartialAggs || root->hasNonSerialAggs)
    7465             :     {
    7466             :         /* Insufficient support for partial mode. */
    7467        2978 :         return false;
    7468             :     }
    7469             : 
    7470             :     /* Everything looks good. */
    7471       30302 :     return true;
    7472             : }
    7473             : 
    7474             : /*
    7475             :  * apply_scanjoin_target_to_paths
    7476             :  *
    7477             :  * Adjust the final scan/join relation, and recursively all of its children,
    7478             :  * to generate the final scan/join target.  It would be more correct to model
    7479             :  * this as a separate planning step with a new RelOptInfo at the toplevel and
    7480             :  * for each child relation, but doing it this way is noticeably cheaper.
    7481             :  * Maybe that problem can be solved at some point, but for now we do this.
    7482             :  *
    7483             :  * If tlist_same_exprs is true, then the scan/join target to be applied has
    7484             :  * the same expressions as the existing reltarget, so we need only insert the
    7485             :  * appropriate sortgroupref information.  By avoiding the creation of
    7486             :  * projection paths we save effort both immediately and at plan creation time.
    7487             :  */
    7488             : static void
    7489      498752 : apply_scanjoin_target_to_paths(PlannerInfo *root,
    7490             :                                RelOptInfo *rel,
    7491             :                                List *scanjoin_targets,
    7492             :                                List *scanjoin_targets_contain_srfs,
    7493             :                                bool scanjoin_target_parallel_safe,
    7494             :                                bool tlist_same_exprs)
    7495             : {
    7496      498752 :     bool        rel_is_partitioned = IS_PARTITIONED_REL(rel);
    7497             :     PathTarget *scanjoin_target;
    7498             :     ListCell   *lc;
    7499             : 
    7500             :     /* This recurses, so be paranoid. */
    7501      498752 :     check_stack_depth();
    7502             : 
    7503             :     /*
    7504             :      * If the rel is partitioned, we want to drop its existing paths and
    7505             :      * generate new ones.  This function would still be correct if we kept the
    7506             :      * existing paths: we'd modify them to generate the correct target above
    7507             :      * the partitioning Append, and then they'd compete on cost with paths
    7508             :      * generating the target below the Append.  However, in our current cost
    7509             :      * model the latter way is always the same or cheaper cost, so modifying
    7510             :      * the existing paths would just be useless work.  Moreover, when the cost
    7511             :      * is the same, varying roundoff errors might sometimes allow an existing
    7512             :      * path to be picked, resulting in undesirable cross-platform plan
    7513             :      * variations.  So we drop old paths and thereby force the work to be done
    7514             :      * below the Append, except in the case of a non-parallel-safe target.
    7515             :      *
    7516             :      * Some care is needed, because we have to allow
    7517             :      * generate_useful_gather_paths to see the old partial paths in the next
    7518             :      * stanza.  Hence, zap the main pathlist here, then allow
    7519             :      * generate_useful_gather_paths to add path(s) to the main list, and
    7520             :      * finally zap the partial pathlist.
    7521             :      */
    7522      498752 :     if (rel_is_partitioned)
    7523       12004 :         rel->pathlist = NIL;
    7524             : 
    7525             :     /*
    7526             :      * If the scan/join target is not parallel-safe, partial paths cannot
    7527             :      * generate it.
    7528             :      */
    7529      498752 :     if (!scanjoin_target_parallel_safe)
    7530             :     {
    7531             :         /*
    7532             :          * Since we can't generate the final scan/join target in parallel
    7533             :          * workers, this is our last opportunity to use any partial paths that
    7534             :          * exist; so build Gather path(s) that use them and emit whatever the
    7535             :          * current reltarget is.  We don't do this in the case where the
    7536             :          * target is parallel-safe, since we will be able to generate superior
    7537             :          * paths by doing it after the final scan/join target has been
    7538             :          * applied.
    7539             :          */
    7540       75244 :         generate_useful_gather_paths(root, rel, false);
    7541             : 
    7542             :         /* Can't use parallel query above this level. */
    7543       75244 :         rel->partial_pathlist = NIL;
    7544       75244 :         rel->consider_parallel = false;
    7545             :     }
    7546             : 
    7547             :     /* Finish dropping old paths for a partitioned rel, per comment above */
    7548      498752 :     if (rel_is_partitioned)
    7549       12004 :         rel->partial_pathlist = NIL;
    7550             : 
    7551             :     /* Extract SRF-free scan/join target. */
    7552      498752 :     scanjoin_target = linitial_node(PathTarget, scanjoin_targets);
    7553             : 
    7554             :     /*
    7555             :      * Apply the SRF-free scan/join target to each existing path.
    7556             :      *
    7557             :      * If the tlist exprs are the same, we can just inject the sortgroupref
    7558             :      * information into the existing pathtargets.  Otherwise, replace each
    7559             :      * path with a projection path that generates the SRF-free scan/join
    7560             :      * target.  This can't change the ordering of paths within rel->pathlist,
    7561             :      * so we just modify the list in place.
    7562             :      */
    7563     1024914 :     foreach(lc, rel->pathlist)
    7564             :     {
    7565      526162 :         Path       *subpath = (Path *) lfirst(lc);
    7566             : 
    7567             :         /* Shouldn't have any parameterized paths anymore */
    7568             :         Assert(subpath->param_info == NULL);
    7569             : 
    7570      526162 :         if (tlist_same_exprs)
    7571      176760 :             subpath->pathtarget->sortgrouprefs =
    7572      176760 :                 scanjoin_target->sortgrouprefs;
    7573             :         else
    7574             :         {
    7575             :             Path       *newpath;
    7576             : 
    7577      349402 :             newpath = (Path *) create_projection_path(root, rel, subpath,
    7578             :                                                       scanjoin_target);
    7579      349402 :             lfirst(lc) = newpath;
    7580             :         }
    7581             :     }
    7582             : 
    7583             :     /* Likewise adjust the targets for any partial paths. */
    7584      517826 :     foreach(lc, rel->partial_pathlist)
    7585             :     {
    7586       19074 :         Path       *subpath = (Path *) lfirst(lc);
    7587             : 
    7588             :         /* Shouldn't have any parameterized paths anymore */
    7589             :         Assert(subpath->param_info == NULL);
    7590             : 
    7591       19074 :         if (tlist_same_exprs)
    7592       15548 :             subpath->pathtarget->sortgrouprefs =
    7593       15548 :                 scanjoin_target->sortgrouprefs;
    7594             :         else
    7595             :         {
    7596             :             Path       *newpath;
    7597             : 
    7598        3526 :             newpath = (Path *) create_projection_path(root, rel, subpath,
    7599             :                                                       scanjoin_target);
    7600        3526 :             lfirst(lc) = newpath;
    7601             :         }
    7602             :     }
    7603             : 
    7604             :     /*
    7605             :      * Now, if final scan/join target contains SRFs, insert ProjectSetPath(s)
    7606             :      * atop each existing path.  (Note that this function doesn't look at the
    7607             :      * cheapest-path fields, which is a good thing because they're bogus right
    7608             :      * now.)
    7609             :      */
    7610      498752 :     if (root->parse->hasTargetSRFs)
    7611        8340 :         adjust_paths_for_srfs(root, rel,
    7612             :                               scanjoin_targets,
    7613             :                               scanjoin_targets_contain_srfs);
    7614             : 
    7615             :     /*
    7616             :      * Update the rel's target to be the final (with SRFs) scan/join target.
    7617             :      * This now matches the actual output of all the paths, and we might get
    7618             :      * confused in createplan.c if they don't agree.  We must do this now so
    7619             :      * that any append paths made in the next part will use the correct
    7620             :      * pathtarget (cf. create_append_path).
    7621             :      *
    7622             :      * Note that this is also necessary if GetForeignUpperPaths() gets called
    7623             :      * on the final scan/join relation or on any of its children, since the
    7624             :      * FDW might look at the rel's target to create ForeignPaths.
    7625             :      */
    7626      498752 :     rel->reltarget = llast_node(PathTarget, scanjoin_targets);
    7627             : 
    7628             :     /*
    7629             :      * If the relation is partitioned, recursively apply the scan/join target
    7630             :      * to all partitions, and generate brand-new Append paths in which the
    7631             :      * scan/join target is computed below the Append rather than above it.
    7632             :      * Since Append is not projection-capable, that might save a separate
    7633             :      * Result node, and it also is important for partitionwise aggregate.
    7634             :      */
    7635      498752 :     if (rel_is_partitioned)
    7636             :     {
    7637       12004 :         List       *live_children = NIL;
    7638             :         int         i;
    7639             : 
    7640             :         /* Adjust each partition. */
    7641       12004 :         i = -1;
    7642       33850 :         while ((i = bms_next_member(rel->live_parts, i)) >= 0)
    7643             :         {
    7644       21846 :             RelOptInfo *child_rel = rel->part_rels[i];
    7645             :             AppendRelInfo **appinfos;
    7646             :             int         nappinfos;
    7647       21846 :             List       *child_scanjoin_targets = NIL;
    7648             : 
    7649             :             Assert(child_rel != NULL);
    7650             : 
    7651             :             /* Dummy children can be ignored. */
    7652       21846 :             if (IS_DUMMY_REL(child_rel))
    7653          42 :                 continue;
    7654             : 
    7655             :             /* Translate scan/join targets for this child. */
    7656       21804 :             appinfos = find_appinfos_by_relids(root, child_rel->relids,
    7657             :                                                &nappinfos);
    7658       43608 :             foreach(lc, scanjoin_targets)
    7659             :             {
    7660       21804 :                 PathTarget *target = lfirst_node(PathTarget, lc);
    7661             : 
    7662       21804 :                 target = copy_pathtarget(target);
    7663       21804 :                 target->exprs = (List *)
    7664       21804 :                     adjust_appendrel_attrs(root,
    7665       21804 :                                            (Node *) target->exprs,
    7666             :                                            nappinfos, appinfos);
    7667       21804 :                 child_scanjoin_targets = lappend(child_scanjoin_targets,
    7668             :                                                  target);
    7669             :             }
    7670       21804 :             pfree(appinfos);
    7671             : 
    7672             :             /* Recursion does the real work. */
    7673       21804 :             apply_scanjoin_target_to_paths(root, child_rel,
    7674             :                                            child_scanjoin_targets,
    7675             :                                            scanjoin_targets_contain_srfs,
    7676             :                                            scanjoin_target_parallel_safe,
    7677             :                                            tlist_same_exprs);
    7678             : 
    7679             :             /* Save non-dummy children for Append paths. */
    7680       21804 :             if (!IS_DUMMY_REL(child_rel))
    7681       21804 :                 live_children = lappend(live_children, child_rel);
    7682             :         }
    7683             : 
    7684             :         /* Build new paths for this relation by appending child paths. */
    7685       12004 :         add_paths_to_append_rel(root, rel, live_children);
    7686             :     }
    7687             : 
    7688             :     /*
    7689             :      * Consider generating Gather or Gather Merge paths.  We must only do this
    7690             :      * if the relation is parallel safe, and we don't do it for child rels to
    7691             :      * avoid creating multiple Gather nodes within the same plan. We must do
    7692             :      * this after all paths have been generated and before set_cheapest, since
    7693             :      * one of the generated paths may turn out to be the cheapest one.
    7694             :      */
    7695      498752 :     if (rel->consider_parallel && !IS_OTHER_REL(rel))
    7696      144634 :         generate_useful_gather_paths(root, rel, false);
    7697             : 
    7698             :     /*
    7699             :      * Reassess which paths are the cheapest, now that we've potentially added
    7700             :      * new Gather (or Gather Merge) and/or Append (or MergeAppend) paths to
    7701             :      * this relation.
    7702             :      */
    7703      498752 :     set_cheapest(rel);
    7704      498752 : }
    7705             : 
    7706             : /*
    7707             :  * create_partitionwise_grouping_paths
    7708             :  *
    7709             :  * If the partition keys of input relation are part of the GROUP BY clause, all
    7710             :  * the rows belonging to a given group come from a single partition.  This
    7711             :  * allows aggregation/grouping over a partitioned relation to be broken down
    7712             :  * into aggregation/grouping on each partition.  This should be no worse, and
    7713             :  * often better, than the normal approach.
    7714             :  *
    7715             :  * However, if the GROUP BY clause does not contain all the partition keys,
    7716             :  * rows from a given group may be spread across multiple partitions. In that
    7717             :  * case, we perform partial aggregation for each group, append the results,
    7718             :  * and then finalize aggregation.  This is less certain to win than the
    7719             :  * previous case.  It may win if the PartialAggregate stage greatly reduces
    7720             :  * the number of groups, because fewer rows will pass through the Append node.
    7721             :  * It may lose if we have lots of small groups.
    7722             :  */
    7723             : static void
    7724         514 : create_partitionwise_grouping_paths(PlannerInfo *root,
    7725             :                                     RelOptInfo *input_rel,
    7726             :                                     RelOptInfo *grouped_rel,
    7727             :                                     RelOptInfo *partially_grouped_rel,
    7728             :                                     const AggClauseCosts *agg_costs,
    7729             :                                     grouping_sets_data *gd,
    7730             :                                     PartitionwiseAggregateType patype,
    7731             :                                     GroupPathExtraData *extra)
    7732             : {
    7733         514 :     List       *grouped_live_children = NIL;
    7734         514 :     List       *partially_grouped_live_children = NIL;
    7735         514 :     PathTarget *target = grouped_rel->reltarget;
    7736         514 :     bool        partial_grouping_valid = true;
    7737             :     int         i;
    7738             : 
    7739             :     Assert(patype != PARTITIONWISE_AGGREGATE_NONE);
    7740             :     Assert(patype != PARTITIONWISE_AGGREGATE_PARTIAL ||
    7741             :            partially_grouped_rel != NULL);
    7742             : 
    7743             :     /* Add paths for partitionwise aggregation/grouping. */
    7744         514 :     i = -1;
    7745        1912 :     while ((i = bms_next_member(input_rel->live_parts, i)) >= 0)
    7746             :     {
    7747        1398 :         RelOptInfo *child_input_rel = input_rel->part_rels[i];
    7748             :         PathTarget *child_target;
    7749             :         AppendRelInfo **appinfos;
    7750             :         int         nappinfos;
    7751             :         GroupPathExtraData child_extra;
    7752             :         RelOptInfo *child_grouped_rel;
    7753             :         RelOptInfo *child_partially_grouped_rel;
    7754             : 
    7755             :         Assert(child_input_rel != NULL);
    7756             : 
    7757             :         /* Dummy children can be ignored. */
    7758        1398 :         if (IS_DUMMY_REL(child_input_rel))
    7759           0 :             continue;
    7760             : 
    7761        1398 :         child_target = copy_pathtarget(target);
    7762             : 
    7763             :         /*
    7764             :          * Copy the given "extra" structure as is and then override the
    7765             :          * members specific to this child.
    7766             :          */
    7767        1398 :         memcpy(&child_extra, extra, sizeof(child_extra));
    7768             : 
    7769        1398 :         appinfos = find_appinfos_by_relids(root, child_input_rel->relids,
    7770             :                                            &nappinfos);
    7771             : 
    7772        1398 :         child_target->exprs = (List *)
    7773        1398 :             adjust_appendrel_attrs(root,
    7774        1398 :                                    (Node *) target->exprs,
    7775             :                                    nappinfos, appinfos);
    7776             : 
    7777             :         /* Translate havingQual and targetList. */
    7778        1398 :         child_extra.havingQual = (Node *)
    7779             :             adjust_appendrel_attrs(root,
    7780             :                                    extra->havingQual,
    7781             :                                    nappinfos, appinfos);
    7782        1398 :         child_extra.targetList = (List *)
    7783        1398 :             adjust_appendrel_attrs(root,
    7784        1398 :                                    (Node *) extra->targetList,
    7785             :                                    nappinfos, appinfos);
    7786             : 
    7787             :         /*
    7788             :          * extra->patype was the value computed for our parent rel; patype is
    7789             :          * the value for this relation.  For the child, our value is its
    7790             :          * parent rel's value.
    7791             :          */
    7792        1398 :         child_extra.patype = patype;
    7793             : 
    7794             :         /*
    7795             :          * Create grouping relation to hold fully aggregated grouping and/or
    7796             :          * aggregation paths for the child.
    7797             :          */
    7798        1398 :         child_grouped_rel = make_grouping_rel(root, child_input_rel,
    7799             :                                               child_target,
    7800        1398 :                                               extra->target_parallel_safe,
    7801             :                                               child_extra.havingQual);
    7802             : 
    7803             :         /* Create grouping paths for this child relation. */
    7804        1398 :         create_ordinary_grouping_paths(root, child_input_rel,
    7805             :                                        child_grouped_rel,
    7806             :                                        agg_costs, gd, &child_extra,
    7807             :                                        &child_partially_grouped_rel);
    7808             : 
    7809        1398 :         if (child_partially_grouped_rel)
    7810             :         {
    7811             :             partially_grouped_live_children =
    7812         882 :                 lappend(partially_grouped_live_children,
    7813             :                         child_partially_grouped_rel);
    7814             :         }
    7815             :         else
    7816         516 :             partial_grouping_valid = false;
    7817             : 
    7818        1398 :         if (patype == PARTITIONWISE_AGGREGATE_FULL)
    7819             :         {
    7820         804 :             set_cheapest(child_grouped_rel);
    7821         804 :             grouped_live_children = lappend(grouped_live_children,
    7822             :                                             child_grouped_rel);
    7823             :         }
    7824             : 
    7825        1398 :         pfree(appinfos);
    7826             :     }
    7827             : 
    7828             :     /*
    7829             :      * Try to create append paths for partially grouped children. For full
    7830             :      * partitionwise aggregation, we might have paths in the partial_pathlist
    7831             :      * if parallel aggregation is possible.  For partial partitionwise
    7832             :      * aggregation, we may have paths in both pathlist and partial_pathlist.
    7833             :      *
    7834             :      * NB: We must have a partially grouped path for every child in order to
    7835             :      * generate a partially grouped path for this relation.
    7836             :      */
    7837         514 :     if (partially_grouped_rel && partial_grouping_valid)
    7838             :     {
    7839             :         Assert(partially_grouped_live_children != NIL);
    7840             : 
    7841         338 :         add_paths_to_append_rel(root, partially_grouped_rel,
    7842             :                                 partially_grouped_live_children);
    7843             : 
    7844             :         /*
    7845             :          * We need call set_cheapest, since the finalization step will use the
    7846             :          * cheapest path from the rel.
    7847             :          */
    7848         338 :         if (partially_grouped_rel->pathlist)
    7849         338 :             set_cheapest(partially_grouped_rel);
    7850             :     }
    7851             : 
    7852             :     /* If possible, create append paths for fully grouped children. */
    7853         514 :     if (patype == PARTITIONWISE_AGGREGATE_FULL)
    7854             :     {
    7855             :         Assert(grouped_live_children != NIL);
    7856             : 
    7857         284 :         add_paths_to_append_rel(root, grouped_rel, grouped_live_children);
    7858             :     }
    7859         514 : }
    7860             : 
    7861             : /*
    7862             :  * group_by_has_partkey
    7863             :  *
    7864             :  * Returns true, if all the partition keys of the given relation are part of
    7865             :  * the GROUP BY clauses, false otherwise.
    7866             :  */
    7867             : static bool
    7868         508 : group_by_has_partkey(RelOptInfo *input_rel,
    7869             :                      List *targetList,
    7870             :                      List *groupClause)
    7871             : {
    7872         508 :     List       *groupexprs = get_sortgrouplist_exprs(groupClause, targetList);
    7873         508 :     int         cnt = 0;
    7874             :     int         partnatts;
    7875             : 
    7876             :     /* Input relation should be partitioned. */
    7877             :     Assert(input_rel->part_scheme);
    7878             : 
    7879             :     /* Rule out early, if there are no partition keys present. */
    7880         508 :     if (!input_rel->partexprs)
    7881           0 :         return false;
    7882             : 
    7883         508 :     partnatts = input_rel->part_scheme->partnatts;
    7884             : 
    7885         828 :     for (cnt = 0; cnt < partnatts; cnt++)
    7886             :     {
    7887         544 :         List       *partexprs = input_rel->partexprs[cnt];
    7888             :         ListCell   *lc;
    7889         544 :         bool        found = false;
    7890             : 
    7891         762 :         foreach(lc, partexprs)
    7892             :         {
    7893         538 :             Expr       *partexpr = lfirst(lc);
    7894             : 
    7895         538 :             if (list_member(groupexprs, partexpr))
    7896             :             {
    7897         320 :                 found = true;
    7898         320 :                 break;
    7899             :             }
    7900             :         }
    7901             : 
    7902             :         /*
    7903             :          * If none of the partition key expressions match with any of the
    7904             :          * GROUP BY expression, return false.
    7905             :          */
    7906         544 :         if (!found)
    7907         224 :             return false;
    7908             :     }
    7909             : 
    7910         284 :     return true;
    7911             : }
    7912             : 
    7913             : /*
    7914             :  * generate_setop_child_grouplist
    7915             :  *      Build a SortGroupClause list defining the sort/grouping properties
    7916             :  *      of the child of a set operation.
    7917             :  *
    7918             :  * This is similar to generate_setop_grouplist() but differs as the setop
    7919             :  * child query's targetlist entries may already have a tleSortGroupRef
    7920             :  * assigned for other purposes, such as GROUP BYs.  Here we keep the
    7921             :  * SortGroupClause list in the same order as 'op' groupClauses and just adjust
    7922             :  * the tleSortGroupRef to reference the TargetEntry's 'ressortgroupref'.
    7923             :  */
    7924             : static List *
    7925       10236 : generate_setop_child_grouplist(SetOperationStmt *op, List *targetlist)
    7926             : {
    7927       10236 :     List       *grouplist = copyObject(op->groupClauses);
    7928             :     ListCell   *lg;
    7929             :     ListCell   *lt;
    7930             : 
    7931       10236 :     lg = list_head(grouplist);
    7932       40316 :     foreach(lt, targetlist)
    7933             :     {
    7934       30080 :         TargetEntry *tle = (TargetEntry *) lfirst(lt);
    7935             :         SortGroupClause *sgc;
    7936             : 
    7937             :         /* resjunk columns could have sortgrouprefs.  Leave these alone */
    7938       30080 :         if (tle->resjunk)
    7939           0 :             continue;
    7940             : 
    7941             :         /* we expect every non-resjunk target to have a SortGroupClause */
    7942             :         Assert(lg != NULL);
    7943       30080 :         sgc = (SortGroupClause *) lfirst(lg);
    7944       30080 :         lg = lnext(grouplist, lg);
    7945             : 
    7946             :         /* assign a tleSortGroupRef, or reuse the existing one */
    7947       30080 :         sgc->tleSortGroupRef = assignSortGroupRef(tle, targetlist);
    7948       30080 :         tle->ressortgroupref = sgc->tleSortGroupRef;
    7949             :     }
    7950             :     Assert(lg == NULL);
    7951       10236 :     return grouplist;
    7952             : }

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