LCOV - code coverage report
Current view: top level - src/backend/optimizer/plan - subselect.c (source / functions) Hit Total Coverage
Test: PostgreSQL 12devel Lines: 800 848 94.3 %
Date: 2019-04-23 21:21:41 Functions: 34 34 100.0 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : /*-------------------------------------------------------------------------
       2             :  *
       3             :  * subselect.c
       4             :  *    Planning routines for subselects.
       5             :  *
       6             :  * This module deals with SubLinks and CTEs, but not subquery RTEs (i.e.,
       7             :  * not sub-SELECT-in-FROM cases).
       8             :  *
       9             :  * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
      10             :  * Portions Copyright (c) 1994, Regents of the University of California
      11             :  *
      12             :  * IDENTIFICATION
      13             :  *    src/backend/optimizer/plan/subselect.c
      14             :  *
      15             :  *-------------------------------------------------------------------------
      16             :  */
      17             : #include "postgres.h"
      18             : 
      19             : #include "access/htup_details.h"
      20             : #include "catalog/pg_operator.h"
      21             : #include "catalog/pg_type.h"
      22             : #include "executor/executor.h"
      23             : #include "miscadmin.h"
      24             : #include "nodes/makefuncs.h"
      25             : #include "nodes/nodeFuncs.h"
      26             : #include "optimizer/clauses.h"
      27             : #include "optimizer/cost.h"
      28             : #include "optimizer/optimizer.h"
      29             : #include "optimizer/paramassign.h"
      30             : #include "optimizer/pathnode.h"
      31             : #include "optimizer/planmain.h"
      32             : #include "optimizer/planner.h"
      33             : #include "optimizer/prep.h"
      34             : #include "optimizer/subselect.h"
      35             : #include "parser/parse_relation.h"
      36             : #include "rewrite/rewriteManip.h"
      37             : #include "utils/builtins.h"
      38             : #include "utils/lsyscache.h"
      39             : #include "utils/syscache.h"
      40             : 
      41             : 
      42             : typedef struct convert_testexpr_context
      43             : {
      44             :     PlannerInfo *root;
      45             :     List       *subst_nodes;    /* Nodes to substitute for Params */
      46             : } convert_testexpr_context;
      47             : 
      48             : typedef struct process_sublinks_context
      49             : {
      50             :     PlannerInfo *root;
      51             :     bool        isTopQual;
      52             : } process_sublinks_context;
      53             : 
      54             : typedef struct finalize_primnode_context
      55             : {
      56             :     PlannerInfo *root;
      57             :     Bitmapset  *paramids;       /* Non-local PARAM_EXEC paramids found */
      58             : } finalize_primnode_context;
      59             : 
      60             : typedef struct inline_cte_walker_context
      61             : {
      62             :     const char *ctename;        /* name and relative level of target CTE */
      63             :     int         levelsup;
      64             :     int         refcount;       /* number of remaining references */
      65             :     Query      *ctequery;       /* query to substitute */
      66             : } inline_cte_walker_context;
      67             : 
      68             : 
      69             : static Node *build_subplan(PlannerInfo *root, Plan *plan, PlannerInfo *subroot,
      70             :               List *plan_params,
      71             :               SubLinkType subLinkType, int subLinkId,
      72             :               Node *testexpr, bool adjust_testexpr,
      73             :               bool unknownEqFalse);
      74             : static List *generate_subquery_params(PlannerInfo *root, List *tlist,
      75             :                          List **paramIds);
      76             : static List *generate_subquery_vars(PlannerInfo *root, List *tlist,
      77             :                        Index varno);
      78             : static Node *convert_testexpr(PlannerInfo *root,
      79             :                  Node *testexpr,
      80             :                  List *subst_nodes);
      81             : static Node *convert_testexpr_mutator(Node *node,
      82             :                          convert_testexpr_context *context);
      83             : static bool subplan_is_hashable(Plan *plan);
      84             : static bool testexpr_is_hashable(Node *testexpr);
      85             : static bool hash_ok_operator(OpExpr *expr);
      86             : static bool contain_dml(Node *node);
      87             : static bool contain_dml_walker(Node *node, void *context);
      88             : static bool contain_outer_selfref(Node *node);
      89             : static bool contain_outer_selfref_walker(Node *node, Index *depth);
      90             : static void inline_cte(PlannerInfo *root, CommonTableExpr *cte);
      91             : static bool inline_cte_walker(Node *node, inline_cte_walker_context *context);
      92             : static bool simplify_EXISTS_query(PlannerInfo *root, Query *query);
      93             : static Query *convert_EXISTS_to_ANY(PlannerInfo *root, Query *subselect,
      94             :                       Node **testexpr, List **paramIds);
      95             : static Node *replace_correlation_vars_mutator(Node *node, PlannerInfo *root);
      96             : static Node *process_sublinks_mutator(Node *node,
      97             :                          process_sublinks_context *context);
      98             : static Bitmapset *finalize_plan(PlannerInfo *root,
      99             :               Plan *plan,
     100             :               int gather_param,
     101             :               Bitmapset *valid_params,
     102             :               Bitmapset *scan_params);
     103             : static bool finalize_primnode(Node *node, finalize_primnode_context *context);
     104             : static bool finalize_agg_primnode(Node *node, finalize_primnode_context *context);
     105             : 
     106             : 
     107             : /*
     108             :  * Get the datatype/typmod/collation of the first column of the plan's output.
     109             :  *
     110             :  * This information is stored for ARRAY_SUBLINK execution and for
     111             :  * exprType()/exprTypmod()/exprCollation(), which have no way to get at the
     112             :  * plan associated with a SubPlan node.  We really only need the info for
     113             :  * EXPR_SUBLINK and ARRAY_SUBLINK subplans, but for consistency we save it
     114             :  * always.
     115             :  */
     116             : static void
     117       44812 : get_first_col_type(Plan *plan, Oid *coltype, int32 *coltypmod,
     118             :                    Oid *colcollation)
     119             : {
     120             :     /* In cases such as EXISTS, tlist might be empty; arbitrarily use VOID */
     121       44812 :     if (plan->targetlist)
     122             :     {
     123       43354 :         TargetEntry *tent = linitial_node(TargetEntry, plan->targetlist);
     124             : 
     125       43354 :         if (!tent->resjunk)
     126             :         {
     127       43354 :             *coltype = exprType((Node *) tent->expr);
     128       43354 :             *coltypmod = exprTypmod((Node *) tent->expr);
     129       43354 :             *colcollation = exprCollation((Node *) tent->expr);
     130       43354 :             return;
     131             :         }
     132             :     }
     133        1458 :     *coltype = VOIDOID;
     134        1458 :     *coltypmod = -1;
     135        1458 :     *colcollation = InvalidOid;
     136             : }
     137             : 
     138             : /*
     139             :  * Convert a SubLink (as created by the parser) into a SubPlan.
     140             :  *
     141             :  * We are given the SubLink's contained query, type, ID, and testexpr.  We are
     142             :  * also told if this expression appears at top level of a WHERE/HAVING qual.
     143             :  *
     144             :  * Note: we assume that the testexpr has been AND/OR flattened (actually,
     145             :  * it's been through eval_const_expressions), but not converted to
     146             :  * implicit-AND form; and any SubLinks in it should already have been
     147             :  * converted to SubPlans.  The subquery is as yet untouched, however.
     148             :  *
     149             :  * The result is whatever we need to substitute in place of the SubLink node
     150             :  * in the executable expression.  If we're going to do the subplan as a
     151             :  * regular subplan, this will be the constructed SubPlan node.  If we're going
     152             :  * to do the subplan as an InitPlan, the SubPlan node instead goes into
     153             :  * root->init_plans, and what we return here is an expression tree
     154             :  * representing the InitPlan's result: usually just a Param node representing
     155             :  * a single scalar result, but possibly a row comparison tree containing
     156             :  * multiple Param nodes, or for a MULTIEXPR subquery a simple NULL constant
     157             :  * (since the real output Params are elsewhere in the tree, and the MULTIEXPR
     158             :  * subquery itself is in a resjunk tlist entry whose value is uninteresting).
     159             :  */
     160             : static Node *
     161       42950 : make_subplan(PlannerInfo *root, Query *orig_subquery,
     162             :              SubLinkType subLinkType, int subLinkId,
     163             :              Node *testexpr, bool isTopQual)
     164             : {
     165             :     Query      *subquery;
     166       42950 :     bool        simple_exists = false;
     167             :     double      tuple_fraction;
     168             :     PlannerInfo *subroot;
     169             :     RelOptInfo *final_rel;
     170             :     Path       *best_path;
     171             :     Plan       *plan;
     172             :     List       *plan_params;
     173             :     Node       *result;
     174             : 
     175             :     /*
     176             :      * Copy the source Query node.  This is a quick and dirty kluge to resolve
     177             :      * the fact that the parser can generate trees with multiple links to the
     178             :      * same sub-Query node, but the planner wants to scribble on the Query.
     179             :      * Try to clean this up when we do querytree redesign...
     180             :      */
     181       42950 :     subquery = copyObject(orig_subquery);
     182             : 
     183             :     /*
     184             :      * If it's an EXISTS subplan, we might be able to simplify it.
     185             :      */
     186       42950 :     if (subLinkType == EXISTS_SUBLINK)
     187        1298 :         simple_exists = simplify_EXISTS_query(root, subquery);
     188             : 
     189             :     /*
     190             :      * For an EXISTS subplan, tell lower-level planner to expect that only the
     191             :      * first tuple will be retrieved.  For ALL and ANY subplans, we will be
     192             :      * able to stop evaluating if the test condition fails or matches, so very
     193             :      * often not all the tuples will be retrieved; for lack of a better idea,
     194             :      * specify 50% retrieval.  For EXPR, MULTIEXPR, and ROWCOMPARE subplans,
     195             :      * use default behavior (we're only expecting one row out, anyway).
     196             :      *
     197             :      * NOTE: if you change these numbers, also change cost_subplan() in
     198             :      * path/costsize.c.
     199             :      *
     200             :      * XXX If an ANY subplan is uncorrelated, build_subplan may decide to hash
     201             :      * its output.  In that case it would've been better to specify full
     202             :      * retrieval.  At present, however, we can only check hashability after
     203             :      * we've made the subplan :-(.  (Determining whether it'll fit in work_mem
     204             :      * is the really hard part.)  Therefore, we don't want to be too
     205             :      * optimistic about the percentage of tuples retrieved, for fear of
     206             :      * selecting a plan that's bad for the materialization case.
     207             :      */
     208       42950 :     if (subLinkType == EXISTS_SUBLINK)
     209        1298 :         tuple_fraction = 1.0;   /* just like a LIMIT 1 */
     210       41652 :     else if (subLinkType == ALL_SUBLINK ||
     211             :              subLinkType == ANY_SUBLINK)
     212         230 :         tuple_fraction = 0.5;   /* 50% */
     213             :     else
     214       41422 :         tuple_fraction = 0.0;   /* default behavior */
     215             : 
     216             :     /* plan_params should not be in use in current query level */
     217             :     Assert(root->plan_params == NIL);
     218             : 
     219             :     /* Generate Paths for the subquery */
     220       42950 :     subroot = subquery_planner(root->glob, subquery,
     221             :                                root,
     222             :                                false, tuple_fraction);
     223             : 
     224             :     /* Isolate the params needed by this specific subplan */
     225       42950 :     plan_params = root->plan_params;
     226       42950 :     root->plan_params = NIL;
     227             : 
     228             :     /*
     229             :      * Select best Path and turn it into a Plan.  At least for now, there
     230             :      * seems no reason to postpone doing that.
     231             :      */
     232       42950 :     final_rel = fetch_upper_rel(subroot, UPPERREL_FINAL, NULL);
     233       42950 :     best_path = get_cheapest_fractional_path(final_rel, tuple_fraction);
     234             : 
     235       42950 :     plan = create_plan(subroot, best_path);
     236             : 
     237             :     /* And convert to SubPlan or InitPlan format. */
     238       42950 :     result = build_subplan(root, plan, subroot, plan_params,
     239             :                            subLinkType, subLinkId,
     240             :                            testexpr, true, isTopQual);
     241             : 
     242             :     /*
     243             :      * If it's a correlated EXISTS with an unimportant targetlist, we might be
     244             :      * able to transform it to the equivalent of an IN and then implement it
     245             :      * by hashing.  We don't have enough information yet to tell which way is
     246             :      * likely to be better (it depends on the expected number of executions of
     247             :      * the EXISTS qual, and we are much too early in planning the outer query
     248             :      * to be able to guess that).  So we generate both plans, if possible, and
     249             :      * leave it to the executor to decide which to use.
     250             :      */
     251       42950 :     if (simple_exists && IsA(result, SubPlan))
     252             :     {
     253             :         Node       *newtestexpr;
     254             :         List       *paramIds;
     255             : 
     256             :         /* Make a second copy of the original subquery */
     257        1144 :         subquery = copyObject(orig_subquery);
     258             :         /* and re-simplify */
     259        1144 :         simple_exists = simplify_EXISTS_query(root, subquery);
     260             :         Assert(simple_exists);
     261             :         /* See if it can be converted to an ANY query */
     262        1144 :         subquery = convert_EXISTS_to_ANY(root, subquery,
     263             :                                          &newtestexpr, &paramIds);
     264        1144 :         if (subquery)
     265             :         {
     266             :             /* Generate Paths for the ANY subquery; we'll need all rows */
     267         818 :             subroot = subquery_planner(root->glob, subquery,
     268             :                                        root,
     269             :                                        false, 0.0);
     270             : 
     271             :             /* Isolate the params needed by this specific subplan */
     272         818 :             plan_params = root->plan_params;
     273         818 :             root->plan_params = NIL;
     274             : 
     275             :             /* Select best Path and turn it into a Plan */
     276         818 :             final_rel = fetch_upper_rel(subroot, UPPERREL_FINAL, NULL);
     277         818 :             best_path = final_rel->cheapest_total_path;
     278             : 
     279         818 :             plan = create_plan(subroot, best_path);
     280             : 
     281             :             /* Now we can check if it'll fit in work_mem */
     282             :             /* XXX can we check this at the Path stage? */
     283         818 :             if (subplan_is_hashable(plan))
     284             :             {
     285             :                 SubPlan    *hashplan;
     286             :                 AlternativeSubPlan *asplan;
     287             : 
     288             :                 /* OK, convert to SubPlan format. */
     289         818 :                 hashplan = castNode(SubPlan,
     290             :                                     build_subplan(root, plan, subroot,
     291             :                                                   plan_params,
     292             :                                                   ANY_SUBLINK, 0,
     293             :                                                   newtestexpr,
     294             :                                                   false, true));
     295             :                 /* Check we got what we expected */
     296             :                 Assert(hashplan->parParam == NIL);
     297             :                 Assert(hashplan->useHashTable);
     298             :                 /* build_subplan won't have filled in paramIds */
     299         818 :                 hashplan->paramIds = paramIds;
     300             : 
     301             :                 /* Leave it to the executor to decide which plan to use */
     302         818 :                 asplan = makeNode(AlternativeSubPlan);
     303         818 :                 asplan->subplans = list_make2(result, hashplan);
     304         818 :                 result = (Node *) asplan;
     305             :             }
     306             :         }
     307             :     }
     308             : 
     309       42950 :     return result;
     310             : }
     311             : 
     312             : /*
     313             :  * Build a SubPlan node given the raw inputs --- subroutine for make_subplan
     314             :  *
     315             :  * Returns either the SubPlan, or a replacement expression if we decide to
     316             :  * make it an InitPlan, as explained in the comments for make_subplan.
     317             :  */
     318             : static Node *
     319       43768 : build_subplan(PlannerInfo *root, Plan *plan, PlannerInfo *subroot,
     320             :               List *plan_params,
     321             :               SubLinkType subLinkType, int subLinkId,
     322             :               Node *testexpr, bool adjust_testexpr,
     323             :               bool unknownEqFalse)
     324             : {
     325             :     Node       *result;
     326             :     SubPlan    *splan;
     327             :     bool        isInitPlan;
     328             :     ListCell   *lc;
     329             : 
     330             :     /*
     331             :      * Initialize the SubPlan node.  Note plan_id, plan_name, and cost fields
     332             :      * are set further down.
     333             :      */
     334       43768 :     splan = makeNode(SubPlan);
     335       43768 :     splan->subLinkType = subLinkType;
     336       43768 :     splan->testexpr = NULL;
     337       43768 :     splan->paramIds = NIL;
     338       43768 :     get_first_col_type(plan, &splan->firstColType, &splan->firstColTypmod,
     339             :                        &splan->firstColCollation);
     340       43768 :     splan->useHashTable = false;
     341       43768 :     splan->unknownEqFalse = unknownEqFalse;
     342       43768 :     splan->parallel_safe = plan->parallel_safe;
     343       43768 :     splan->setParam = NIL;
     344       43768 :     splan->parParam = NIL;
     345       43768 :     splan->args = NIL;
     346             : 
     347             :     /*
     348             :      * Make parParam and args lists of param IDs and expressions that current
     349             :      * query level will pass to this child plan.
     350             :      */
     351       94996 :     foreach(lc, plan_params)
     352             :     {
     353       51228 :         PlannerParamItem *pitem = (PlannerParamItem *) lfirst(lc);
     354       51228 :         Node       *arg = pitem->item;
     355             : 
     356             :         /*
     357             :          * The Var, PlaceHolderVar, or Aggref has already been adjusted to
     358             :          * have the correct varlevelsup, phlevelsup, or agglevelsup.
     359             :          *
     360             :          * If it's a PlaceHolderVar or Aggref, its arguments might contain
     361             :          * SubLinks, which have not yet been processed (see the comments for
     362             :          * SS_replace_correlation_vars).  Do that now.
     363             :          */
     364      102448 :         if (IsA(arg, PlaceHolderVar) ||
     365       51220 :             IsA(arg, Aggref))
     366          40 :             arg = SS_process_sublinks(root, arg, false);
     367             : 
     368       51228 :         splan->parParam = lappend_int(splan->parParam, pitem->paramId);
     369       51228 :         splan->args = lappend(splan->args, arg);
     370             :     }
     371             : 
     372             :     /*
     373             :      * Un-correlated or undirect correlated plans of EXISTS, EXPR, ARRAY,
     374             :      * ROWCOMPARE, or MULTIEXPR types can be used as initPlans.  For EXISTS,
     375             :      * EXPR, or ARRAY, we return a Param referring to the result of evaluating
     376             :      * the initPlan.  For ROWCOMPARE, we must modify the testexpr tree to
     377             :      * contain PARAM_EXEC Params instead of the PARAM_SUBLINK Params emitted
     378             :      * by the parser, and then return that tree.  For MULTIEXPR, we return a
     379             :      * null constant: the resjunk targetlist item containing the SubLink does
     380             :      * not need to return anything useful, since the referencing Params are
     381             :      * elsewhere.
     382             :      */
     383       43768 :     if (splan->parParam == NIL && subLinkType == EXISTS_SUBLINK)
     384         150 :     {
     385             :         Param      *prm;
     386             : 
     387             :         Assert(testexpr == NULL);
     388         150 :         prm = generate_new_exec_param(root, BOOLOID, -1, InvalidOid);
     389         150 :         splan->setParam = list_make1_int(prm->paramid);
     390         150 :         isInitPlan = true;
     391         150 :         result = (Node *) prm;
     392             :     }
     393       43618 :     else if (splan->parParam == NIL && subLinkType == EXPR_SUBLINK)
     394        8204 :     {
     395        8204 :         TargetEntry *te = linitial(plan->targetlist);
     396             :         Param      *prm;
     397             : 
     398             :         Assert(!te->resjunk);
     399             :         Assert(testexpr == NULL);
     400       24612 :         prm = generate_new_exec_param(root,
     401        8204 :                                       exprType((Node *) te->expr),
     402        8204 :                                       exprTypmod((Node *) te->expr),
     403        8204 :                                       exprCollation((Node *) te->expr));
     404        8204 :         splan->setParam = list_make1_int(prm->paramid);
     405        8204 :         isInitPlan = true;
     406        8204 :         result = (Node *) prm;
     407             :     }
     408       35414 :     else if (splan->parParam == NIL && subLinkType == ARRAY_SUBLINK)
     409          58 :     {
     410          58 :         TargetEntry *te = linitial(plan->targetlist);
     411             :         Oid         arraytype;
     412             :         Param      *prm;
     413             : 
     414             :         Assert(!te->resjunk);
     415             :         Assert(testexpr == NULL);
     416          58 :         arraytype = get_promoted_array_type(exprType((Node *) te->expr));
     417          58 :         if (!OidIsValid(arraytype))
     418           0 :             elog(ERROR, "could not find array type for datatype %s",
     419             :                  format_type_be(exprType((Node *) te->expr)));
     420         116 :         prm = generate_new_exec_param(root,
     421             :                                       arraytype,
     422          58 :                                       exprTypmod((Node *) te->expr),
     423          58 :                                       exprCollation((Node *) te->expr));
     424          58 :         splan->setParam = list_make1_int(prm->paramid);
     425          58 :         isInitPlan = true;
     426          58 :         result = (Node *) prm;
     427             :     }
     428       35356 :     else if (splan->parParam == NIL && subLinkType == ROWCOMPARE_SUBLINK)
     429           0 :     {
     430             :         /* Adjust the Params */
     431             :         List       *params;
     432             : 
     433             :         Assert(testexpr != NULL);
     434           0 :         params = generate_subquery_params(root,
     435             :                                           plan->targetlist,
     436             :                                           &splan->paramIds);
     437           0 :         result = convert_testexpr(root,
     438             :                                   testexpr,
     439             :                                   params);
     440           0 :         splan->setParam = list_copy(splan->paramIds);
     441           0 :         isInitPlan = true;
     442             : 
     443             :         /*
     444             :          * The executable expression is returned to become part of the outer
     445             :          * plan's expression tree; it is not kept in the initplan node.
     446             :          */
     447             :     }
     448       35356 :     else if (subLinkType == MULTIEXPR_SUBLINK)
     449             :     {
     450             :         /*
     451             :          * Whether it's an initplan or not, it needs to set a PARAM_EXEC Param
     452             :          * for each output column.
     453             :          */
     454             :         List       *params;
     455             : 
     456             :         Assert(testexpr == NULL);
     457          44 :         params = generate_subquery_params(root,
     458             :                                           plan->targetlist,
     459             :                                           &splan->setParam);
     460             : 
     461             :         /*
     462             :          * Save the list of replacement Params in the n'th cell of
     463             :          * root->multiexpr_params; setrefs.c will use it to replace
     464             :          * PARAM_MULTIEXPR Params.
     465             :          */
     466         132 :         while (list_length(root->multiexpr_params) < subLinkId)
     467          44 :             root->multiexpr_params = lappend(root->multiexpr_params, NIL);
     468          44 :         lc = list_nth_cell(root->multiexpr_params, subLinkId - 1);
     469             :         Assert(lfirst(lc) == NIL);
     470          44 :         lfirst(lc) = params;
     471             : 
     472             :         /* It can be an initplan if there are no parParams. */
     473          44 :         if (splan->parParam == NIL)
     474             :         {
     475          16 :             isInitPlan = true;
     476          16 :             result = (Node *) makeNullConst(RECORDOID, -1, InvalidOid);
     477             :         }
     478             :         else
     479             :         {
     480          28 :             isInitPlan = false;
     481          28 :             result = (Node *) splan;
     482             :         }
     483             :     }
     484             :     else
     485             :     {
     486             :         /*
     487             :          * Adjust the Params in the testexpr, unless caller said it's not
     488             :          * needed.
     489             :          */
     490       35312 :         if (testexpr && adjust_testexpr)
     491         230 :         {
     492             :             List       *params;
     493             : 
     494         230 :             params = generate_subquery_params(root,
     495             :                                               plan->targetlist,
     496             :                                               &splan->paramIds);
     497         230 :             splan->testexpr = convert_testexpr(root,
     498             :                                                testexpr,
     499             :                                                params);
     500             :         }
     501             :         else
     502       35082 :             splan->testexpr = testexpr;
     503             : 
     504             :         /*
     505             :          * We can't convert subplans of ALL_SUBLINK or ANY_SUBLINK types to
     506             :          * initPlans, even when they are uncorrelated or undirect correlated,
     507             :          * because we need to scan the output of the subplan for each outer
     508             :          * tuple.  But if it's a not-direct-correlated IN (= ANY) test, we
     509             :          * might be able to use a hashtable to avoid comparing all the tuples.
     510             :          */
     511       36348 :         if (subLinkType == ANY_SUBLINK &&
     512        1984 :             splan->parParam == NIL &&
     513        1896 :             subplan_is_hashable(plan) &&
     514         948 :             testexpr_is_hashable(splan->testexpr))
     515         948 :             splan->useHashTable = true;
     516             : 
     517             :         /*
     518             :          * Otherwise, we have the option to tack a Material node onto the top
     519             :          * of the subplan, to reduce the cost of reading it repeatedly.  This
     520             :          * is pointless for a direct-correlated subplan, since we'd have to
     521             :          * recompute its results each time anyway.  For uncorrelated/undirect
     522             :          * correlated subplans, we add Material unless the subplan's top plan
     523             :          * node would materialize its output anyway.  Also, if enable_material
     524             :          * is false, then the user does not want us to materialize anything
     525             :          * unnecessarily, so we don't.
     526             :          */
     527       34376 :         else if (splan->parParam == NIL && enable_material &&
     528          12 :                  !ExecMaterializesOutput(nodeTag(plan)))
     529          12 :             plan = materialize_finished_plan(plan);
     530             : 
     531       35312 :         result = (Node *) splan;
     532       35312 :         isInitPlan = false;
     533             :     }
     534             : 
     535             :     /*
     536             :      * Add the subplan and its PlannerInfo to the global lists.
     537             :      */
     538       43768 :     root->glob->subplans = lappend(root->glob->subplans, plan);
     539       43768 :     root->glob->subroots = lappend(root->glob->subroots, subroot);
     540       43768 :     splan->plan_id = list_length(root->glob->subplans);
     541             : 
     542       43768 :     if (isInitPlan)
     543        8428 :         root->init_plans = lappend(root->init_plans, splan);
     544             : 
     545             :     /*
     546             :      * A parameterless subplan (not initplan) should be prepared to handle
     547             :      * REWIND efficiently.  If it has direct parameters then there's no point
     548             :      * since it'll be reset on each scan anyway; and if it's an initplan then
     549             :      * there's no point since it won't get re-run without parameter changes
     550             :      * anyway.  The input of a hashed subplan doesn't need REWIND either.
     551             :      */
     552       43768 :     if (splan->parParam == NIL && !isInitPlan && !splan->useHashTable)
     553          12 :         root->glob->rewindPlanIDs = bms_add_member(root->glob->rewindPlanIDs,
     554             :                                                    splan->plan_id);
     555             : 
     556             :     /* Label the subplan for EXPLAIN purposes */
     557       43768 :     splan->plan_name = palloc(32 + 12 * list_length(splan->setParam));
     558       43768 :     sprintf(splan->plan_name, "%s %d",
     559             :             isInitPlan ? "InitPlan" : "SubPlan",
     560             :             splan->plan_id);
     561       43768 :     if (splan->setParam)
     562             :     {
     563        8456 :         char       *ptr = splan->plan_name + strlen(splan->plan_name);
     564             : 
     565        8456 :         ptr += sprintf(ptr, " (returns ");
     566       16956 :         foreach(lc, splan->setParam)
     567             :         {
     568        8500 :             ptr += sprintf(ptr, "$%d%s",
     569             :                            lfirst_int(lc),
     570        8500 :                            lnext(lc) ? "," : ")");
     571             :         }
     572             :     }
     573             : 
     574             :     /* Lastly, fill in the cost estimates for use later */
     575       43768 :     cost_subplan(root, splan, plan);
     576             : 
     577       43768 :     return result;
     578             : }
     579             : 
     580             : /*
     581             :  * generate_subquery_params: build a list of Params representing the output
     582             :  * columns of a sublink's sub-select, given the sub-select's targetlist.
     583             :  *
     584             :  * We also return an integer list of the paramids of the Params.
     585             :  */
     586             : static List *
     587         274 : generate_subquery_params(PlannerInfo *root, List *tlist, List **paramIds)
     588             : {
     589             :     List       *result;
     590             :     List       *ids;
     591             :     ListCell   *lc;
     592             : 
     593         274 :     result = ids = NIL;
     594         628 :     foreach(lc, tlist)
     595             :     {
     596         354 :         TargetEntry *tent = (TargetEntry *) lfirst(lc);
     597             :         Param      *param;
     598             : 
     599         354 :         if (tent->resjunk)
     600           4 :             continue;
     601             : 
     602        1050 :         param = generate_new_exec_param(root,
     603         350 :                                         exprType((Node *) tent->expr),
     604         350 :                                         exprTypmod((Node *) tent->expr),
     605         350 :                                         exprCollation((Node *) tent->expr));
     606         350 :         result = lappend(result, param);
     607         350 :         ids = lappend_int(ids, param->paramid);
     608             :     }
     609             : 
     610         274 :     *paramIds = ids;
     611         274 :     return result;
     612             : }
     613             : 
     614             : /*
     615             :  * generate_subquery_vars: build a list of Vars representing the output
     616             :  * columns of a sublink's sub-select, given the sub-select's targetlist.
     617             :  * The Vars have the specified varno (RTE index).
     618             :  */
     619             : static List *
     620         532 : generate_subquery_vars(PlannerInfo *root, List *tlist, Index varno)
     621             : {
     622             :     List       *result;
     623             :     ListCell   *lc;
     624             : 
     625         532 :     result = NIL;
     626        1088 :     foreach(lc, tlist)
     627             :     {
     628         556 :         TargetEntry *tent = (TargetEntry *) lfirst(lc);
     629             :         Var        *var;
     630             : 
     631         556 :         if (tent->resjunk)
     632           0 :             continue;
     633             : 
     634         556 :         var = makeVarFromTargetEntry(varno, tent);
     635         556 :         result = lappend(result, var);
     636             :     }
     637             : 
     638         532 :     return result;
     639             : }
     640             : 
     641             : /*
     642             :  * convert_testexpr: convert the testexpr given by the parser into
     643             :  * actually executable form.  This entails replacing PARAM_SUBLINK Params
     644             :  * with Params or Vars representing the results of the sub-select.  The
     645             :  * nodes to be substituted are passed in as the List result from
     646             :  * generate_subquery_params or generate_subquery_vars.
     647             :  */
     648             : static Node *
     649         762 : convert_testexpr(PlannerInfo *root,
     650             :                  Node *testexpr,
     651             :                  List *subst_nodes)
     652             : {
     653             :     convert_testexpr_context context;
     654             : 
     655         762 :     context.root = root;
     656         762 :     context.subst_nodes = subst_nodes;
     657         762 :     return convert_testexpr_mutator(testexpr, &context);
     658             : }
     659             : 
     660             : static Node *
     661        3768 : convert_testexpr_mutator(Node *node,
     662             :                          convert_testexpr_context *context)
     663             : {
     664        3768 :     if (node == NULL)
     665          12 :         return NULL;
     666        3756 :     if (IsA(node, Param))
     667             :     {
     668         818 :         Param      *param = (Param *) node;
     669             : 
     670         818 :         if (param->paramkind == PARAM_SUBLINK)
     671             :         {
     672        1636 :             if (param->paramid <= 0 ||
     673         818 :                 param->paramid > list_length(context->subst_nodes))
     674           0 :                 elog(ERROR, "unexpected PARAM_SUBLINK ID: %d", param->paramid);
     675             : 
     676             :             /*
     677             :              * We copy the list item to avoid having doubly-linked
     678             :              * substructure in the modified parse tree.  This is probably
     679             :              * unnecessary when it's a Param, but be safe.
     680             :              */
     681         818 :             return (Node *) copyObject(list_nth(context->subst_nodes,
     682             :                                                 param->paramid - 1));
     683             :         }
     684             :     }
     685        2938 :     if (IsA(node, SubLink))
     686             :     {
     687             :         /*
     688             :          * If we come across a nested SubLink, it is neither necessary nor
     689             :          * correct to recurse into it: any PARAM_SUBLINKs we might find inside
     690             :          * belong to the inner SubLink not the outer. So just return it as-is.
     691             :          *
     692             :          * This reasoning depends on the assumption that nothing will pull
     693             :          * subexpressions into or out of the testexpr field of a SubLink, at
     694             :          * least not without replacing PARAM_SUBLINKs first.  If we did want
     695             :          * to do that we'd need to rethink the parser-output representation
     696             :          * altogether, since currently PARAM_SUBLINKs are only unique per
     697             :          * SubLink not globally across the query.  The whole point of
     698             :          * replacing them with Vars or PARAM_EXEC nodes is to make them
     699             :          * globally unique before they escape from the SubLink's testexpr.
     700             :          *
     701             :          * Note: this can't happen when called during SS_process_sublinks,
     702             :          * because that recursively processes inner SubLinks first.  It can
     703             :          * happen when called from convert_ANY_sublink_to_join, though.
     704             :          */
     705           8 :         return node;
     706             :     }
     707        2930 :     return expression_tree_mutator(node,
     708             :                                    convert_testexpr_mutator,
     709             :                                    (void *) context);
     710             : }
     711             : 
     712             : /*
     713             :  * subplan_is_hashable: can we implement an ANY subplan by hashing?
     714             :  */
     715             : static bool
     716        1766 : subplan_is_hashable(Plan *plan)
     717             : {
     718             :     double      subquery_size;
     719             : 
     720             :     /*
     721             :      * The estimated size of the subquery result must fit in work_mem. (Note:
     722             :      * we use heap tuple overhead here even though the tuples will actually be
     723             :      * stored as MinimalTuples; this provides some fudge factor for hashtable
     724             :      * overhead.)
     725             :      */
     726        3532 :     subquery_size = plan->plan_rows *
     727        1766 :         (MAXALIGN(plan->plan_width) + MAXALIGN(SizeofHeapTupleHeader));
     728        1766 :     if (subquery_size > work_mem * 1024L)
     729           0 :         return false;
     730             : 
     731        1766 :     return true;
     732             : }
     733             : 
     734             : /*
     735             :  * testexpr_is_hashable: is an ANY SubLink's test expression hashable?
     736             :  */
     737             : static bool
     738         948 : testexpr_is_hashable(Node *testexpr)
     739             : {
     740             :     /*
     741             :      * The testexpr must be a single OpExpr, or an AND-clause containing only
     742             :      * OpExprs.
     743             :      *
     744             :      * The combining operators must be hashable and strict. The need for
     745             :      * hashability is obvious, since we want to use hashing. Without
     746             :      * strictness, behavior in the presence of nulls is too unpredictable.  We
     747             :      * actually must assume even more than plain strictness: they can't yield
     748             :      * NULL for non-null inputs, either (see nodeSubplan.c).  However, hash
     749             :      * indexes and hash joins assume that too.
     750             :      */
     751         948 :     if (testexpr && IsA(testexpr, OpExpr))
     752             :     {
     753         756 :         if (hash_ok_operator((OpExpr *) testexpr))
     754         756 :             return true;
     755             :     }
     756         192 :     else if (is_andclause(testexpr))
     757             :     {
     758             :         ListCell   *l;
     759             : 
     760         576 :         foreach(l, ((BoolExpr *) testexpr)->args)
     761             :         {
     762         384 :             Node       *andarg = (Node *) lfirst(l);
     763             : 
     764         384 :             if (!IsA(andarg, OpExpr))
     765           0 :                 return false;
     766         384 :             if (!hash_ok_operator((OpExpr *) andarg))
     767           0 :                 return false;
     768             :         }
     769         192 :         return true;
     770             :     }
     771             : 
     772           0 :     return false;
     773             : }
     774             : 
     775             : /*
     776             :  * Check expression is hashable + strict
     777             :  *
     778             :  * We could use op_hashjoinable() and op_strict(), but do it like this to
     779             :  * avoid a redundant cache lookup.
     780             :  */
     781             : static bool
     782        4198 : hash_ok_operator(OpExpr *expr)
     783             : {
     784        4198 :     Oid         opid = expr->opno;
     785             : 
     786             :     /* quick out if not a binary operator */
     787        4198 :     if (list_length(expr->args) != 2)
     788           0 :         return false;
     789        4198 :     if (opid == ARRAY_EQ_OP)
     790             :     {
     791             :         /* array_eq is strict, but must check input type to ensure hashable */
     792             :         /* XXX record_eq will need same treatment when it becomes hashable */
     793           0 :         Node       *leftarg = linitial(expr->args);
     794             : 
     795           0 :         return op_hashjoinable(opid, exprType(leftarg));
     796             :     }
     797             :     else
     798             :     {
     799             :         /* else must look up the operator properties */
     800             :         HeapTuple   tup;
     801             :         Form_pg_operator optup;
     802             : 
     803        4198 :         tup = SearchSysCache1(OPEROID, ObjectIdGetDatum(opid));
     804        4198 :         if (!HeapTupleIsValid(tup))
     805           0 :             elog(ERROR, "cache lookup failed for operator %u", opid);
     806        4198 :         optup = (Form_pg_operator) GETSTRUCT(tup);
     807        4198 :         if (!optup->oprcanhash || !func_strict(optup->oprcode))
     808             :         {
     809         328 :             ReleaseSysCache(tup);
     810         328 :             return false;
     811             :         }
     812        3870 :         ReleaseSysCache(tup);
     813        3870 :         return true;
     814             :     }
     815             : }
     816             : 
     817             : 
     818             : /*
     819             :  * SS_process_ctes: process a query's WITH list
     820             :  *
     821             :  * Consider each CTE in the WITH list and either ignore it (if it's an
     822             :  * unreferenced SELECT), "inline" it to create a regular sub-SELECT-in-FROM,
     823             :  * or convert it to an initplan.
     824             :  *
     825             :  * A side effect is to fill in root->cte_plan_ids with a list that
     826             :  * parallels root->parse->cteList and provides the subplan ID for
     827             :  * each CTE's initplan, or a dummy ID (-1) if we didn't make an initplan.
     828             :  */
     829             : void
     830        1158 : SS_process_ctes(PlannerInfo *root)
     831             : {
     832             :     ListCell   *lc;
     833             : 
     834             :     Assert(root->cte_plan_ids == NIL);
     835             : 
     836        2478 :     foreach(lc, root->parse->cteList)
     837             :     {
     838        1320 :         CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
     839        1320 :         CmdType     cmdType = ((Query *) cte->ctequery)->commandType;
     840             :         Query      *subquery;
     841             :         PlannerInfo *subroot;
     842             :         RelOptInfo *final_rel;
     843             :         Path       *best_path;
     844             :         Plan       *plan;
     845             :         SubPlan    *splan;
     846             :         int         paramid;
     847             : 
     848             :         /*
     849             :          * Ignore SELECT CTEs that are not actually referenced anywhere.
     850             :          */
     851        1320 :         if (cte->cterefcount == 0 && cmdType == CMD_SELECT)
     852             :         {
     853             :             /* Make a dummy entry in cte_plan_ids */
     854           8 :             root->cte_plan_ids = lappend_int(root->cte_plan_ids, -1);
     855           8 :             continue;
     856             :         }
     857             : 
     858             :         /*
     859             :          * Consider inlining the CTE (creating RTE_SUBQUERY RTE(s)) instead of
     860             :          * implementing it as a separately-planned CTE.
     861             :          *
     862             :          * We cannot inline if any of these conditions hold:
     863             :          *
     864             :          * 1. The user said not to (the CTEMaterializeAlways option).
     865             :          *
     866             :          * 2. The CTE is recursive.
     867             :          *
     868             :          * 3. The CTE has side-effects; this includes either not being a plain
     869             :          * SELECT, or containing volatile functions.  Inlining might change
     870             :          * the side-effects, which would be bad.
     871             :          *
     872             :          * 4. The CTE is multiply-referenced and contains a self-reference to
     873             :          * a recursive CTE outside itself.  Inlining would result in multiple
     874             :          * recursive self-references, which we don't support.
     875             :          *
     876             :          * Otherwise, we have an option whether to inline or not.  That should
     877             :          * always be a win if there's just a single reference, but if the CTE
     878             :          * is multiply-referenced then it's unclear: inlining adds duplicate
     879             :          * computations, but the ability to absorb restrictions from the outer
     880             :          * query level could outweigh that.  We do not have nearly enough
     881             :          * information at this point to tell whether that's true, so we let
     882             :          * the user express a preference.  Our default behavior is to inline
     883             :          * only singly-referenced CTEs, but a CTE marked CTEMaterializeNever
     884             :          * will be inlined even if multiply referenced.
     885             :          *
     886             :          * Note: we check for volatile functions last, because that's more
     887             :          * expensive than the other tests needed.
     888             :          */
     889        2604 :         if ((cte->ctematerialized == CTEMaterializeNever ||
     890        2516 :              (cte->ctematerialized == CTEMaterializeDefault &&
     891        2308 :               cte->cterefcount == 1)) &&
     892        1866 :             !cte->cterecursive &&
     893         646 :             cmdType == CMD_SELECT &&
     894        1286 :             !contain_dml(cte->ctequery) &&
     895         652 :             (cte->cterefcount <= 1 ||
     896         644 :              !contain_outer_selfref(cte->ctequery)) &&
     897         632 :             !contain_volatile_functions(cte->ctequery))
     898             :         {
     899         628 :             inline_cte(root, cte);
     900             :             /* Make a dummy entry in cte_plan_ids */
     901         628 :             root->cte_plan_ids = lappend_int(root->cte_plan_ids, -1);
     902         628 :             continue;
     903             :         }
     904             : 
     905             :         /*
     906             :          * Copy the source Query node.  Probably not necessary, but let's keep
     907             :          * this similar to make_subplan.
     908             :          */
     909         684 :         subquery = (Query *) copyObject(cte->ctequery);
     910             : 
     911             :         /* plan_params should not be in use in current query level */
     912             :         Assert(root->plan_params == NIL);
     913             : 
     914             :         /*
     915             :          * Generate Paths for the CTE query.  Always plan for full retrieval
     916             :          * --- we don't have enough info to predict otherwise.
     917             :          */
     918         684 :         subroot = subquery_planner(root->glob, subquery,
     919             :                                    root,
     920         684 :                                    cte->cterecursive, 0.0);
     921             : 
     922             :         /*
     923             :          * Since the current query level doesn't yet contain any RTEs, it
     924             :          * should not be possible for the CTE to have requested parameters of
     925             :          * this level.
     926             :          */
     927         684 :         if (root->plan_params)
     928           0 :             elog(ERROR, "unexpected outer reference in CTE query");
     929             : 
     930             :         /*
     931             :          * Select best Path and turn it into a Plan.  At least for now, there
     932             :          * seems no reason to postpone doing that.
     933             :          */
     934         684 :         final_rel = fetch_upper_rel(subroot, UPPERREL_FINAL, NULL);
     935         684 :         best_path = final_rel->cheapest_total_path;
     936             : 
     937         684 :         plan = create_plan(subroot, best_path);
     938             : 
     939             :         /*
     940             :          * Make a SubPlan node for it.  This is just enough unlike
     941             :          * build_subplan that we can't share code.
     942             :          *
     943             :          * Note plan_id, plan_name, and cost fields are set further down.
     944             :          */
     945         684 :         splan = makeNode(SubPlan);
     946         684 :         splan->subLinkType = CTE_SUBLINK;
     947         684 :         splan->testexpr = NULL;
     948         684 :         splan->paramIds = NIL;
     949         684 :         get_first_col_type(plan, &splan->firstColType, &splan->firstColTypmod,
     950             :                            &splan->firstColCollation);
     951         684 :         splan->useHashTable = false;
     952         684 :         splan->unknownEqFalse = false;
     953             : 
     954             :         /*
     955             :          * CTE scans are not considered for parallelism (cf
     956             :          * set_rel_consider_parallel), and even if they were, initPlans aren't
     957             :          * parallel-safe.
     958             :          */
     959         684 :         splan->parallel_safe = false;
     960         684 :         splan->setParam = NIL;
     961         684 :         splan->parParam = NIL;
     962         684 :         splan->args = NIL;
     963             : 
     964             :         /*
     965             :          * The node can't have any inputs (since it's an initplan), so the
     966             :          * parParam and args lists remain empty.  (It could contain references
     967             :          * to earlier CTEs' output param IDs, but CTE outputs are not
     968             :          * propagated via the args list.)
     969             :          */
     970             : 
     971             :         /*
     972             :          * Assign a param ID to represent the CTE's output.  No ordinary
     973             :          * "evaluation" of this param slot ever happens, but we use the param
     974             :          * ID for setParam/chgParam signaling just as if the CTE plan were
     975             :          * returning a simple scalar output.  (Also, the executor abuses the
     976             :          * ParamExecData slot for this param ID for communication among
     977             :          * multiple CteScan nodes that might be scanning this CTE.)
     978             :          */
     979         684 :         paramid = assign_special_exec_param(root);
     980         684 :         splan->setParam = list_make1_int(paramid);
     981             : 
     982             :         /*
     983             :          * Add the subplan and its PlannerInfo to the global lists.
     984             :          */
     985         684 :         root->glob->subplans = lappend(root->glob->subplans, plan);
     986         684 :         root->glob->subroots = lappend(root->glob->subroots, subroot);
     987         684 :         splan->plan_id = list_length(root->glob->subplans);
     988             : 
     989         684 :         root->init_plans = lappend(root->init_plans, splan);
     990             : 
     991         684 :         root->cte_plan_ids = lappend_int(root->cte_plan_ids, splan->plan_id);
     992             : 
     993             :         /* Label the subplan for EXPLAIN purposes */
     994         684 :         splan->plan_name = psprintf("CTE %s", cte->ctename);
     995             : 
     996             :         /* Lastly, fill in the cost estimates for use later */
     997         684 :         cost_subplan(root, splan, plan);
     998             :     }
     999        1158 : }
    1000             : 
    1001             : /*
    1002             :  * contain_dml: is any subquery not a plain SELECT?
    1003             :  *
    1004             :  * We reject SELECT FOR UPDATE/SHARE as well as INSERT etc.
    1005             :  */
    1006             : static bool
    1007         646 : contain_dml(Node *node)
    1008             : {
    1009         646 :     return contain_dml_walker(node, NULL);
    1010             : }
    1011             : 
    1012             : static bool
    1013       41872 : contain_dml_walker(Node *node, void *context)
    1014             : {
    1015       41872 :     if (node == NULL)
    1016       10348 :         return false;
    1017       31524 :     if (IsA(node, Query))
    1018             :     {
    1019         874 :         Query      *query = (Query *) node;
    1020             : 
    1021        1748 :         if (query->commandType != CMD_SELECT ||
    1022         874 :             query->rowMarks != NIL)
    1023           6 :             return true;
    1024             : 
    1025         868 :         return query_tree_walker(query, contain_dml_walker, context, 0);
    1026             :     }
    1027       30650 :     return expression_tree_walker(node, contain_dml_walker, context);
    1028             : }
    1029             : 
    1030             : /*
    1031             :  * contain_outer_selfref: is there an external recursive self-reference?
    1032             :  */
    1033             : static bool
    1034          12 : contain_outer_selfref(Node *node)
    1035             : {
    1036          12 :     Index       depth = 0;
    1037             : 
    1038             :     /*
    1039             :      * We should be starting with a Query, so that depth will be 1 while
    1040             :      * examining its immediate contents.
    1041             :      */
    1042             :     Assert(IsA(node, Query));
    1043             : 
    1044          12 :     return contain_outer_selfref_walker(node, &depth);
    1045             : }
    1046             : 
    1047             : static bool
    1048         300 : contain_outer_selfref_walker(Node *node, Index *depth)
    1049             : {
    1050         300 :     if (node == NULL)
    1051         156 :         return false;
    1052         144 :     if (IsA(node, RangeTblEntry))
    1053             :     {
    1054          16 :         RangeTblEntry *rte = (RangeTblEntry *) node;
    1055             : 
    1056             :         /*
    1057             :          * Check for a self-reference to a CTE that's above the Query that our
    1058             :          * search started at.
    1059             :          */
    1060          24 :         if (rte->rtekind == RTE_CTE &&
    1061          16 :             rte->self_reference &&
    1062           8 :             rte->ctelevelsup >= *depth)
    1063           8 :             return true;
    1064           8 :         return false;           /* allow range_table_walker to continue */
    1065             :     }
    1066         128 :     if (IsA(node, Query))
    1067             :     {
    1068             :         /* Recurse into subquery, tracking nesting depth properly */
    1069          16 :         Query      *query = (Query *) node;
    1070             :         bool        result;
    1071             : 
    1072          16 :         (*depth)++;
    1073             : 
    1074          16 :         result = query_tree_walker(query, contain_outer_selfref_walker,
    1075             :                                    (void *) depth, QTW_EXAMINE_RTES_BEFORE);
    1076             : 
    1077          16 :         (*depth)--;
    1078             : 
    1079          16 :         return result;
    1080             :     }
    1081         112 :     return expression_tree_walker(node, contain_outer_selfref_walker,
    1082             :                                   (void *) depth);
    1083             : }
    1084             : 
    1085             : /*
    1086             :  * inline_cte: convert RTE_CTE references to given CTE into RTE_SUBQUERYs
    1087             :  */
    1088             : static void
    1089         628 : inline_cte(PlannerInfo *root, CommonTableExpr *cte)
    1090             : {
    1091             :     struct inline_cte_walker_context context;
    1092             : 
    1093         628 :     context.ctename = cte->ctename;
    1094             :     /* Start at levelsup = -1 because we'll immediately increment it */
    1095         628 :     context.levelsup = -1;
    1096         628 :     context.refcount = cte->cterefcount;
    1097         628 :     context.ctequery = castNode(Query, cte->ctequery);
    1098             : 
    1099         628 :     (void) inline_cte_walker((Node *) root->parse, &context);
    1100             : 
    1101             :     /* Assert we replaced all references */
    1102             :     Assert(context.refcount == 0);
    1103         628 : }
    1104             : 
    1105             : static bool
    1106      113870 : inline_cte_walker(Node *node, inline_cte_walker_context *context)
    1107             : {
    1108      113870 :     if (node == NULL)
    1109       32252 :         return false;
    1110       81618 :     if (IsA(node, Query))
    1111             :     {
    1112        2920 :         Query      *query = (Query *) node;
    1113             : 
    1114        2920 :         context->levelsup++;
    1115             : 
    1116             :         /*
    1117             :          * Visit the query's RTE nodes after their contents; otherwise
    1118             :          * query_tree_walker would descend into the newly inlined CTE query,
    1119             :          * which we don't want.
    1120             :          */
    1121        2920 :         (void) query_tree_walker(query, inline_cte_walker, context,
    1122             :                                  QTW_EXAMINE_RTES_AFTER);
    1123             : 
    1124        2920 :         context->levelsup--;
    1125             : 
    1126        2920 :         return false;
    1127             :     }
    1128       78698 :     else if (IsA(node, RangeTblEntry))
    1129             :     {
    1130        4572 :         RangeTblEntry *rte = (RangeTblEntry *) node;
    1131             : 
    1132        5610 :         if (rte->rtekind == RTE_CTE &&
    1133        1670 :             strcmp(rte->ctename, context->ctename) == 0 &&
    1134         632 :             rte->ctelevelsup == context->levelsup)
    1135             :         {
    1136             :             /*
    1137             :              * Found a reference to replace.  Generate a copy of the CTE query
    1138             :              * with appropriate level adjustment for outer references (e.g.,
    1139             :              * to other CTEs).
    1140             :              */
    1141         632 :             Query      *newquery = copyObject(context->ctequery);
    1142             : 
    1143         632 :             if (context->levelsup > 0)
    1144         474 :                 IncrementVarSublevelsUp((Node *) newquery, context->levelsup, 1);
    1145             : 
    1146             :             /*
    1147             :              * Convert the RTE_CTE RTE into a RTE_SUBQUERY.
    1148             :              *
    1149             :              * Historically, a FOR UPDATE clause has been treated as extending
    1150             :              * into views and subqueries, but not into CTEs.  We preserve this
    1151             :              * distinction by not trying to push rowmarks into the new
    1152             :              * subquery.
    1153             :              */
    1154         632 :             rte->rtekind = RTE_SUBQUERY;
    1155         632 :             rte->subquery = newquery;
    1156         632 :             rte->security_barrier = false;
    1157             : 
    1158             :             /* Zero out CTE-specific fields */
    1159         632 :             rte->ctename = NULL;
    1160         632 :             rte->ctelevelsup = 0;
    1161         632 :             rte->self_reference = false;
    1162         632 :             rte->coltypes = NIL;
    1163         632 :             rte->coltypmods = NIL;
    1164         632 :             rte->colcollations = NIL;
    1165             : 
    1166             :             /* Count the number of replacements we've done */
    1167         632 :             context->refcount--;
    1168             :         }
    1169             : 
    1170        4572 :         return false;
    1171             :     }
    1172             : 
    1173       74126 :     return expression_tree_walker(node, inline_cte_walker, context);
    1174             : }
    1175             : 
    1176             : 
    1177             : /*
    1178             :  * convert_ANY_sublink_to_join: try to convert an ANY SubLink to a join
    1179             :  *
    1180             :  * The caller has found an ANY SubLink at the top level of one of the query's
    1181             :  * qual clauses, but has not checked the properties of the SubLink further.
    1182             :  * Decide whether it is appropriate to process this SubLink in join style.
    1183             :  * If so, form a JoinExpr and return it.  Return NULL if the SubLink cannot
    1184             :  * be converted to a join.
    1185             :  *
    1186             :  * The only non-obvious input parameter is available_rels: this is the set
    1187             :  * of query rels that can safely be referenced in the sublink expression.
    1188             :  * (We must restrict this to avoid changing the semantics when a sublink
    1189             :  * is present in an outer join's ON qual.)  The conversion must fail if
    1190             :  * the converted qual would reference any but these parent-query relids.
    1191             :  *
    1192             :  * On success, the returned JoinExpr has larg = NULL and rarg = the jointree
    1193             :  * item representing the pulled-up subquery.  The caller must set larg to
    1194             :  * represent the relation(s) on the lefthand side of the new join, and insert
    1195             :  * the JoinExpr into the upper query's jointree at an appropriate place
    1196             :  * (typically, where the lefthand relation(s) had been).  Note that the
    1197             :  * passed-in SubLink must also be removed from its original position in the
    1198             :  * query quals, since the quals of the returned JoinExpr replace it.
    1199             :  * (Notionally, we replace the SubLink with a constant TRUE, then elide the
    1200             :  * redundant constant from the qual.)
    1201             :  *
    1202             :  * On success, the caller is also responsible for recursively applying
    1203             :  * pull_up_sublinks processing to the rarg and quals of the returned JoinExpr.
    1204             :  * (On failure, there is no need to do anything, since pull_up_sublinks will
    1205             :  * be applied when we recursively plan the sub-select.)
    1206             :  *
    1207             :  * Side effects of a successful conversion include adding the SubLink's
    1208             :  * subselect to the query's rangetable, so that it can be referenced in
    1209             :  * the JoinExpr's rarg.
    1210             :  */
    1211             : JoinExpr *
    1212         620 : convert_ANY_sublink_to_join(PlannerInfo *root, SubLink *sublink,
    1213             :                             Relids available_rels)
    1214             : {
    1215             :     JoinExpr   *result;
    1216         620 :     Query      *parse = root->parse;
    1217         620 :     Query      *subselect = (Query *) sublink->subselect;
    1218             :     Relids      upper_varnos;
    1219             :     int         rtindex;
    1220             :     RangeTblEntry *rte;
    1221             :     RangeTblRef *rtr;
    1222             :     List       *subquery_vars;
    1223             :     Node       *quals;
    1224             :     ParseState *pstate;
    1225             : 
    1226             :     Assert(sublink->subLinkType == ANY_SUBLINK);
    1227             : 
    1228             :     /*
    1229             :      * The sub-select must not refer to any Vars of the parent query. (Vars of
    1230             :      * higher levels should be okay, though.)
    1231             :      */
    1232         620 :     if (contain_vars_of_level((Node *) subselect, 1))
    1233          80 :         return NULL;
    1234             : 
    1235             :     /*
    1236             :      * The test expression must contain some Vars of the parent query, else
    1237             :      * it's not gonna be a join.  (Note that it won't have Vars referring to
    1238             :      * the subquery, rather Params.)
    1239             :      */
    1240         540 :     upper_varnos = pull_varnos(sublink->testexpr);
    1241         540 :     if (bms_is_empty(upper_varnos))
    1242           8 :         return NULL;
    1243             : 
    1244             :     /*
    1245             :      * However, it can't refer to anything outside available_rels.
    1246             :      */
    1247         532 :     if (!bms_is_subset(upper_varnos, available_rels))
    1248           0 :         return NULL;
    1249             : 
    1250             :     /*
    1251             :      * The combining operators and left-hand expressions mustn't be volatile.
    1252             :      */
    1253         532 :     if (contain_volatile_functions(sublink->testexpr))
    1254           0 :         return NULL;
    1255             : 
    1256             :     /* Create a dummy ParseState for addRangeTableEntryForSubquery */
    1257         532 :     pstate = make_parsestate(NULL);
    1258             : 
    1259             :     /*
    1260             :      * Okay, pull up the sub-select into upper range table.
    1261             :      *
    1262             :      * We rely here on the assumption that the outer query has no references
    1263             :      * to the inner (necessarily true, other than the Vars that we build
    1264             :      * below). Therefore this is a lot easier than what pull_up_subqueries has
    1265             :      * to go through.
    1266             :      */
    1267         532 :     rte = addRangeTableEntryForSubquery(pstate,
    1268             :                                         subselect,
    1269             :                                         makeAlias("ANY_subquery", NIL),
    1270             :                                         false,
    1271             :                                         false);
    1272         532 :     parse->rtable = lappend(parse->rtable, rte);
    1273         532 :     rtindex = list_length(parse->rtable);
    1274             : 
    1275             :     /*
    1276             :      * Form a RangeTblRef for the pulled-up sub-select.
    1277             :      */
    1278         532 :     rtr = makeNode(RangeTblRef);
    1279         532 :     rtr->rtindex = rtindex;
    1280             : 
    1281             :     /*
    1282             :      * Build a list of Vars representing the subselect outputs.
    1283             :      */
    1284         532 :     subquery_vars = generate_subquery_vars(root,
    1285             :                                            subselect->targetList,
    1286             :                                            rtindex);
    1287             : 
    1288             :     /*
    1289             :      * Build the new join's qual expression, replacing Params with these Vars.
    1290             :      */
    1291         532 :     quals = convert_testexpr(root, sublink->testexpr, subquery_vars);
    1292             : 
    1293             :     /*
    1294             :      * And finally, build the JoinExpr node.
    1295             :      */
    1296         532 :     result = makeNode(JoinExpr);
    1297         532 :     result->jointype = JOIN_SEMI;
    1298         532 :     result->isNatural = false;
    1299         532 :     result->larg = NULL;     /* caller must fill this in */
    1300         532 :     result->rarg = (Node *) rtr;
    1301         532 :     result->usingClause = NIL;
    1302         532 :     result->quals = quals;
    1303         532 :     result->alias = NULL;
    1304         532 :     result->rtindex = 0;     /* we don't need an RTE for it */
    1305             : 
    1306         532 :     return result;
    1307             : }
    1308             : 
    1309             : /*
    1310             :  * convert_EXISTS_sublink_to_join: try to convert an EXISTS SubLink to a join
    1311             :  *
    1312             :  * The API of this function is identical to convert_ANY_sublink_to_join's,
    1313             :  * except that we also support the case where the caller has found NOT EXISTS,
    1314             :  * so we need an additional input parameter "under_not".
    1315             :  */
    1316             : JoinExpr *
    1317        7458 : convert_EXISTS_sublink_to_join(PlannerInfo *root, SubLink *sublink,
    1318             :                                bool under_not, Relids available_rels)
    1319             : {
    1320             :     JoinExpr   *result;
    1321        7458 :     Query      *parse = root->parse;
    1322        7458 :     Query      *subselect = (Query *) sublink->subselect;
    1323             :     Node       *whereClause;
    1324             :     int         rtoffset;
    1325             :     int         varno;
    1326             :     Relids      clause_varnos;
    1327             :     Relids      upper_varnos;
    1328             : 
    1329             :     Assert(sublink->subLinkType == EXISTS_SUBLINK);
    1330             : 
    1331             :     /*
    1332             :      * Can't flatten if it contains WITH.  (We could arrange to pull up the
    1333             :      * WITH into the parent query's cteList, but that risks changing the
    1334             :      * semantics, since a WITH ought to be executed once per associated query
    1335             :      * call.)  Note that convert_ANY_sublink_to_join doesn't have to reject
    1336             :      * this case, since it just produces a subquery RTE that doesn't have to
    1337             :      * get flattened into the parent query.
    1338             :      */
    1339        7458 :     if (subselect->cteList)
    1340           0 :         return NULL;
    1341             : 
    1342             :     /*
    1343             :      * Copy the subquery so we can modify it safely (see comments in
    1344             :      * make_subplan).
    1345             :      */
    1346        7458 :     subselect = copyObject(subselect);
    1347             : 
    1348             :     /*
    1349             :      * See if the subquery can be simplified based on the knowledge that it's
    1350             :      * being used in EXISTS().  If we aren't able to get rid of its
    1351             :      * targetlist, we have to fail, because the pullup operation leaves us
    1352             :      * with noplace to evaluate the targetlist.
    1353             :      */
    1354        7458 :     if (!simplify_EXISTS_query(root, subselect))
    1355           4 :         return NULL;
    1356             : 
    1357             :     /*
    1358             :      * Separate out the WHERE clause.  (We could theoretically also remove
    1359             :      * top-level plain JOIN/ON clauses, but it's probably not worth the
    1360             :      * trouble.)
    1361             :      */
    1362        7454 :     whereClause = subselect->jointree->quals;
    1363        7454 :     subselect->jointree->quals = NULL;
    1364             : 
    1365             :     /*
    1366             :      * The rest of the sub-select must not refer to any Vars of the parent
    1367             :      * query.  (Vars of higher levels should be okay, though.)
    1368             :      */
    1369        7454 :     if (contain_vars_of_level((Node *) subselect, 1))
    1370           0 :         return NULL;
    1371             : 
    1372             :     /*
    1373             :      * On the other hand, the WHERE clause must contain some Vars of the
    1374             :      * parent query, else it's not gonna be a join.
    1375             :      */
    1376        7454 :     if (!contain_vars_of_level(whereClause, 1))
    1377          40 :         return NULL;
    1378             : 
    1379             :     /*
    1380             :      * We don't risk optimizing if the WHERE clause is volatile, either.
    1381             :      */
    1382        7414 :     if (contain_volatile_functions(whereClause))
    1383           0 :         return NULL;
    1384             : 
    1385             :     /*
    1386             :      * The subquery must have a nonempty jointree, but we can make it so.
    1387             :      */
    1388        7414 :     replace_empty_jointree(subselect);
    1389             : 
    1390             :     /*
    1391             :      * Prepare to pull up the sub-select into top range table.
    1392             :      *
    1393             :      * We rely here on the assumption that the outer query has no references
    1394             :      * to the inner (necessarily true). Therefore this is a lot easier than
    1395             :      * what pull_up_subqueries has to go through.
    1396             :      *
    1397             :      * In fact, it's even easier than what convert_ANY_sublink_to_join has to
    1398             :      * do.  The machinations of simplify_EXISTS_query ensured that there is
    1399             :      * nothing interesting in the subquery except an rtable and jointree, and
    1400             :      * even the jointree FromExpr no longer has quals.  So we can just append
    1401             :      * the rtable to our own and use the FromExpr in our jointree. But first,
    1402             :      * adjust all level-zero varnos in the subquery to account for the rtable
    1403             :      * merger.
    1404             :      */
    1405        7414 :     rtoffset = list_length(parse->rtable);
    1406        7414 :     OffsetVarNodes((Node *) subselect, rtoffset, 0);
    1407        7414 :     OffsetVarNodes(whereClause, rtoffset, 0);
    1408             : 
    1409             :     /*
    1410             :      * Upper-level vars in subquery will now be one level closer to their
    1411             :      * parent than before; in particular, anything that had been level 1
    1412             :      * becomes level zero.
    1413             :      */
    1414        7414 :     IncrementVarSublevelsUp((Node *) subselect, -1, 1);
    1415        7414 :     IncrementVarSublevelsUp(whereClause, -1, 1);
    1416             : 
    1417             :     /*
    1418             :      * Now that the WHERE clause is adjusted to match the parent query
    1419             :      * environment, we can easily identify all the level-zero rels it uses.
    1420             :      * The ones <= rtoffset belong to the upper query; the ones > rtoffset do
    1421             :      * not.
    1422             :      */
    1423        7414 :     clause_varnos = pull_varnos(whereClause);
    1424        7414 :     upper_varnos = NULL;
    1425       29668 :     while ((varno = bms_first_member(clause_varnos)) >= 0)
    1426             :     {
    1427       14840 :         if (varno <= rtoffset)
    1428        7430 :             upper_varnos = bms_add_member(upper_varnos, varno);
    1429             :     }
    1430        7414 :     bms_free(clause_varnos);
    1431             :     Assert(!bms_is_empty(upper_varnos));
    1432             : 
    1433             :     /*
    1434             :      * Now that we've got the set of upper-level varnos, we can make the last
    1435             :      * check: only available_rels can be referenced.
    1436             :      */
    1437        7414 :     if (!bms_is_subset(upper_varnos, available_rels))
    1438           0 :         return NULL;
    1439             : 
    1440             :     /* Now we can attach the modified subquery rtable to the parent */
    1441        7414 :     parse->rtable = list_concat(parse->rtable, subselect->rtable);
    1442             : 
    1443             :     /*
    1444             :      * And finally, build the JoinExpr node.
    1445             :      */
    1446        7414 :     result = makeNode(JoinExpr);
    1447        7414 :     result->jointype = under_not ? JOIN_ANTI : JOIN_SEMI;
    1448        7414 :     result->isNatural = false;
    1449        7414 :     result->larg = NULL;     /* caller must fill this in */
    1450             :     /* flatten out the FromExpr node if it's useless */
    1451        7414 :     if (list_length(subselect->jointree->fromlist) == 1)
    1452        7410 :         result->rarg = (Node *) linitial(subselect->jointree->fromlist);
    1453             :     else
    1454           4 :         result->rarg = (Node *) subselect->jointree;
    1455        7414 :     result->usingClause = NIL;
    1456        7414 :     result->quals = whereClause;
    1457        7414 :     result->alias = NULL;
    1458        7414 :     result->rtindex = 0;     /* we don't need an RTE for it */
    1459             : 
    1460        7414 :     return result;
    1461             : }
    1462             : 
    1463             : /*
    1464             :  * simplify_EXISTS_query: remove any useless stuff in an EXISTS's subquery
    1465             :  *
    1466             :  * The only thing that matters about an EXISTS query is whether it returns
    1467             :  * zero or more than zero rows.  Therefore, we can remove certain SQL features
    1468             :  * that won't affect that.  The only part that is really likely to matter in
    1469             :  * typical usage is simplifying the targetlist: it's a common habit to write
    1470             :  * "SELECT * FROM" even though there is no need to evaluate any columns.
    1471             :  *
    1472             :  * Note: by suppressing the targetlist we could cause an observable behavioral
    1473             :  * change, namely that any errors that might occur in evaluating the tlist
    1474             :  * won't occur, nor will other side-effects of volatile functions.  This seems
    1475             :  * unlikely to bother anyone in practice.
    1476             :  *
    1477             :  * Returns true if was able to discard the targetlist, else false.
    1478             :  */
    1479             : static bool
    1480        9900 : simplify_EXISTS_query(PlannerInfo *root, Query *query)
    1481             : {
    1482             :     /*
    1483             :      * We don't try to simplify at all if the query uses set operations,
    1484             :      * aggregates, grouping sets, SRFs, modifying CTEs, HAVING, OFFSET, or FOR
    1485             :      * UPDATE/SHARE; none of these seem likely in normal usage and their
    1486             :      * possible effects are complex.  (Note: we could ignore an "OFFSET 0"
    1487             :      * clause, but that traditionally is used as an optimization fence, so we
    1488             :      * don't.)
    1489             :      */
    1490       19800 :     if (query->commandType != CMD_SELECT ||
    1491       19800 :         query->setOperations ||
    1492       19800 :         query->hasAggs ||
    1493       19800 :         query->groupingSets ||
    1494       19800 :         query->hasWindowFuncs ||
    1495       19800 :         query->hasTargetSRFs ||
    1496       19800 :         query->hasModifyingCTE ||
    1497       19800 :         query->havingQual ||
    1498       19800 :         query->limitOffset ||
    1499        9900 :         query->rowMarks)
    1500           0 :         return false;
    1501             : 
    1502             :     /*
    1503             :      * LIMIT with a constant positive (or NULL) value doesn't affect the
    1504             :      * semantics of EXISTS, so let's ignore such clauses.  This is worth doing
    1505             :      * because people accustomed to certain other DBMSes may be in the habit
    1506             :      * of writing EXISTS(SELECT ... LIMIT 1) as an optimization.  If there's a
    1507             :      * LIMIT with anything else as argument, though, we can't simplify.
    1508             :      */
    1509        9900 :     if (query->limitCount)
    1510             :     {
    1511             :         /*
    1512             :          * The LIMIT clause has not yet been through eval_const_expressions,
    1513             :          * so we have to apply that here.  It might seem like this is a waste
    1514             :          * of cycles, since the only case plausibly worth worrying about is
    1515             :          * "LIMIT 1" ... but what we'll actually see is "LIMIT int8(1::int4)",
    1516             :          * so we have to fold constants or we're not going to recognize it.
    1517             :          */
    1518          16 :         Node       *node = eval_const_expressions(root, query->limitCount);
    1519             :         Const      *limit;
    1520             : 
    1521             :         /* Might as well update the query if we simplified the clause. */
    1522          16 :         query->limitCount = node;
    1523             : 
    1524          16 :         if (!IsA(node, Const))
    1525           0 :             return false;
    1526             : 
    1527          16 :         limit = (Const *) node;
    1528             :         Assert(limit->consttype == INT8OID);
    1529          16 :         if (!limit->constisnull && DatumGetInt64(limit->constvalue) <= 0)
    1530           8 :             return false;
    1531             : 
    1532             :         /* Whether or not the targetlist is safe, we can drop the LIMIT. */
    1533           8 :         query->limitCount = NULL;
    1534             :     }
    1535             : 
    1536             :     /*
    1537             :      * Otherwise, we can throw away the targetlist, as well as any GROUP,
    1538             :      * WINDOW, DISTINCT, and ORDER BY clauses; none of those clauses will
    1539             :      * change a nonzero-rows result to zero rows or vice versa.  (Furthermore,
    1540             :      * since our parsetree representation of these clauses depends on the
    1541             :      * targetlist, we'd better throw them away if we drop the targetlist.)
    1542             :      */
    1543        9892 :     query->targetList = NIL;
    1544        9892 :     query->groupClause = NIL;
    1545        9892 :     query->windowClause = NIL;
    1546        9892 :     query->distinctClause = NIL;
    1547        9892 :     query->sortClause = NIL;
    1548        9892 :     query->hasDistinctOn = false;
    1549             : 
    1550        9892 :     return true;
    1551             : }
    1552             : 
    1553             : /*
    1554             :  * convert_EXISTS_to_ANY: try to convert EXISTS to a hashable ANY sublink
    1555             :  *
    1556             :  * The subselect is expected to be a fresh copy that we can munge up,
    1557             :  * and to have been successfully passed through simplify_EXISTS_query.
    1558             :  *
    1559             :  * On success, the modified subselect is returned, and we store a suitable
    1560             :  * upper-level test expression at *testexpr, plus a list of the subselect's
    1561             :  * output Params at *paramIds.  (The test expression is already Param-ified
    1562             :  * and hence need not go through convert_testexpr, which is why we have to
    1563             :  * deal with the Param IDs specially.)
    1564             :  *
    1565             :  * On failure, returns NULL.
    1566             :  */
    1567             : static Query *
    1568        1144 : convert_EXISTS_to_ANY(PlannerInfo *root, Query *subselect,
    1569             :                       Node **testexpr, List **paramIds)
    1570             : {
    1571             :     Node       *whereClause;
    1572             :     List       *leftargs,
    1573             :                *rightargs,
    1574             :                *opids,
    1575             :                *opcollations,
    1576             :                *newWhere,
    1577             :                *tlist,
    1578             :                *testlist,
    1579             :                *paramids;
    1580             :     ListCell   *lc,
    1581             :                *rc,
    1582             :                *oc,
    1583             :                *cc;
    1584             :     AttrNumber  resno;
    1585             : 
    1586             :     /*
    1587             :      * Query must not require a targetlist, since we have to insert a new one.
    1588             :      * Caller should have dealt with the case already.
    1589             :      */
    1590             :     Assert(subselect->targetList == NIL);
    1591             : 
    1592             :     /*
    1593             :      * Separate out the WHERE clause.  (We could theoretically also remove
    1594             :      * top-level plain JOIN/ON clauses, but it's probably not worth the
    1595             :      * trouble.)
    1596             :      */
    1597        1144 :     whereClause = subselect->jointree->quals;
    1598        1144 :     subselect->jointree->quals = NULL;
    1599             : 
    1600             :     /*
    1601             :      * The rest of the sub-select must not refer to any Vars of the parent
    1602             :      * query.  (Vars of higher levels should be okay, though.)
    1603             :      *
    1604             :      * Note: we need not check for Aggrefs separately because we know the
    1605             :      * sub-select is as yet unoptimized; any uplevel Aggref must therefore
    1606             :      * contain an uplevel Var reference.  This is not the case below ...
    1607             :      */
    1608        1144 :     if (contain_vars_of_level((Node *) subselect, 1))
    1609         164 :         return NULL;
    1610             : 
    1611             :     /*
    1612             :      * We don't risk optimizing if the WHERE clause is volatile, either.
    1613             :      */
    1614         980 :     if (contain_volatile_functions(whereClause))
    1615           0 :         return NULL;
    1616             : 
    1617             :     /*
    1618             :      * Clean up the WHERE clause by doing const-simplification etc on it.
    1619             :      * Aside from simplifying the processing we're about to do, this is
    1620             :      * important for being able to pull chunks of the WHERE clause up into the
    1621             :      * parent query.  Since we are invoked partway through the parent's
    1622             :      * preprocess_expression() work, earlier steps of preprocess_expression()
    1623             :      * wouldn't get applied to the pulled-up stuff unless we do them here. For
    1624             :      * the parts of the WHERE clause that get put back into the child query,
    1625             :      * this work is partially duplicative, but it shouldn't hurt.
    1626             :      *
    1627             :      * Note: we do not run flatten_join_alias_vars.  This is OK because any
    1628             :      * parent aliases were flattened already, and we're not going to pull any
    1629             :      * child Vars (of any description) into the parent.
    1630             :      *
    1631             :      * Note: passing the parent's root to eval_const_expressions is
    1632             :      * technically wrong, but we can get away with it since only the
    1633             :      * boundParams (if any) are used, and those would be the same in a
    1634             :      * subroot.
    1635             :      */
    1636         980 :     whereClause = eval_const_expressions(root, whereClause);
    1637         980 :     whereClause = (Node *) canonicalize_qual((Expr *) whereClause, false);
    1638         980 :     whereClause = (Node *) make_ands_implicit((Expr *) whereClause);
    1639             : 
    1640             :     /*
    1641             :      * We now have a flattened implicit-AND list of clauses, which we try to
    1642             :      * break apart into "outervar = innervar" hash clauses. Anything that
    1643             :      * can't be broken apart just goes back into the newWhere list.  Note that
    1644             :      * we aren't trying hard yet to ensure that we have only outer or only
    1645             :      * inner on each side; we'll check that if we get to the end.
    1646             :      */
    1647         980 :     leftargs = rightargs = opids = opcollations = newWhere = NIL;
    1648        3716 :     foreach(lc, (List *) whereClause)
    1649             :     {
    1650        2736 :         OpExpr     *expr = (OpExpr *) lfirst(lc);
    1651             : 
    1652        4990 :         if (IsA(expr, OpExpr) &&
    1653        2254 :             hash_ok_operator(expr))
    1654             :         {
    1655        1926 :             Node       *leftarg = (Node *) linitial(expr->args);
    1656        1926 :             Node       *rightarg = (Node *) lsecond(expr->args);
    1657             : 
    1658        1926 :             if (contain_vars_of_level(leftarg, 1))
    1659             :             {
    1660         174 :                 leftargs = lappend(leftargs, leftarg);
    1661         174 :                 rightargs = lappend(rightargs, rightarg);
    1662         174 :                 opids = lappend_oid(opids, expr->opno);
    1663         174 :                 opcollations = lappend_oid(opcollations, expr->inputcollid);
    1664         174 :                 continue;
    1665             :             }
    1666        1752 :             if (contain_vars_of_level(rightarg, 1))
    1667             :             {
    1668             :                 /*
    1669             :                  * We must commute the clause to put the outer var on the
    1670             :                  * left, because the hashing code in nodeSubplan.c expects
    1671             :                  * that.  This probably shouldn't ever fail, since hashable
    1672             :                  * operators ought to have commutators, but be paranoid.
    1673             :                  */
    1674         804 :                 expr->opno = get_commutator(expr->opno);
    1675         804 :                 if (OidIsValid(expr->opno) && hash_ok_operator(expr))
    1676             :                 {
    1677         804 :                     leftargs = lappend(leftargs, rightarg);
    1678         804 :                     rightargs = lappend(rightargs, leftarg);
    1679         804 :                     opids = lappend_oid(opids, expr->opno);
    1680         804 :                     opcollations = lappend_oid(opcollations, expr->inputcollid);
    1681         804 :                     continue;
    1682             :                 }
    1683             :                 /* If no commutator, no chance to optimize the WHERE clause */
    1684           0 :                 return NULL;
    1685             :             }
    1686             :         }
    1687             :         /* Couldn't handle it as a hash clause */
    1688        1758 :         newWhere = lappend(newWhere, expr);
    1689             :     }
    1690             : 
    1691             :     /*
    1692             :      * If we didn't find anything we could convert, fail.
    1693             :      */
    1694         980 :     if (leftargs == NIL)
    1695         162 :         return NULL;
    1696             : 
    1697             :     /*
    1698             :      * There mustn't be any parent Vars or Aggs in the stuff that we intend to
    1699             :      * put back into the child query.  Note: you might think we don't need to
    1700             :      * check for Aggs separately, because an uplevel Agg must contain an
    1701             :      * uplevel Var in its argument.  But it is possible that the uplevel Var
    1702             :      * got optimized away by eval_const_expressions.  Consider
    1703             :      *
    1704             :      * SUM(CASE WHEN false THEN uplevelvar ELSE 0 END)
    1705             :      */
    1706        1636 :     if (contain_vars_of_level((Node *) newWhere, 1) ||
    1707         818 :         contain_vars_of_level((Node *) rightargs, 1))
    1708           0 :         return NULL;
    1709         830 :     if (root->parse->hasAggs &&
    1710          24 :         (contain_aggs_of_level((Node *) newWhere, 1) ||
    1711          12 :          contain_aggs_of_level((Node *) rightargs, 1)))
    1712           0 :         return NULL;
    1713             : 
    1714             :     /*
    1715             :      * And there can't be any child Vars in the stuff we intend to pull up.
    1716             :      * (Note: we'd need to check for child Aggs too, except we know the child
    1717             :      * has no aggs at all because of simplify_EXISTS_query's check. The same
    1718             :      * goes for window functions.)
    1719             :      */
    1720         818 :     if (contain_vars_of_level((Node *) leftargs, 0))
    1721           0 :         return NULL;
    1722             : 
    1723             :     /*
    1724             :      * Also reject sublinks in the stuff we intend to pull up.  (It might be
    1725             :      * possible to support this, but doesn't seem worth the complication.)
    1726             :      */
    1727         818 :     if (contain_subplans((Node *) leftargs))
    1728           0 :         return NULL;
    1729             : 
    1730             :     /*
    1731             :      * Okay, adjust the sublevelsup in the stuff we're pulling up.
    1732             :      */
    1733         818 :     IncrementVarSublevelsUp((Node *) leftargs, -1, 1);
    1734             : 
    1735             :     /*
    1736             :      * Put back any child-level-only WHERE clauses.
    1737             :      */
    1738         818 :     if (newWhere)
    1739         714 :         subselect->jointree->quals = (Node *) make_ands_explicit(newWhere);
    1740             : 
    1741             :     /*
    1742             :      * Build a new targetlist for the child that emits the expressions we
    1743             :      * need.  Concurrently, build a testexpr for the parent using Params to
    1744             :      * reference the child outputs.  (Since we generate Params directly here,
    1745             :      * there will be no need to convert the testexpr in build_subplan.)
    1746             :      */
    1747         818 :     tlist = testlist = paramids = NIL;
    1748         818 :     resno = 1;
    1749        1796 :     forfour(lc, leftargs, rc, rightargs, oc, opids, cc, opcollations)
    1750             :     {
    1751         978 :         Node       *leftarg = (Node *) lfirst(lc);
    1752         978 :         Node       *rightarg = (Node *) lfirst(rc);
    1753         978 :         Oid         opid = lfirst_oid(oc);
    1754         978 :         Oid         opcollation = lfirst_oid(cc);
    1755             :         Param      *param;
    1756             : 
    1757         978 :         param = generate_new_exec_param(root,
    1758             :                                         exprType(rightarg),
    1759             :                                         exprTypmod(rightarg),
    1760             :                                         exprCollation(rightarg));
    1761         978 :         tlist = lappend(tlist,
    1762         978 :                         makeTargetEntry((Expr *) rightarg,
    1763         978 :                                         resno++,
    1764             :                                         NULL,
    1765             :                                         false));
    1766         978 :         testlist = lappend(testlist,
    1767         978 :                            make_opclause(opid, BOOLOID, false,
    1768             :                                          (Expr *) leftarg, (Expr *) param,
    1769             :                                          InvalidOid, opcollation));
    1770         978 :         paramids = lappend_int(paramids, param->paramid);
    1771             :     }
    1772             : 
    1773             :     /* Put everything where it should go, and we're done */
    1774         818 :     subselect->targetList = tlist;
    1775         818 :     *testexpr = (Node *) make_ands_explicit(testlist);
    1776         818 :     *paramIds = paramids;
    1777             : 
    1778         818 :     return subselect;
    1779             : }
    1780             : 
    1781             : 
    1782             : /*
    1783             :  * Replace correlation vars (uplevel vars) with Params.
    1784             :  *
    1785             :  * Uplevel PlaceHolderVars and aggregates are replaced, too.
    1786             :  *
    1787             :  * Note: it is critical that this runs immediately after SS_process_sublinks.
    1788             :  * Since we do not recurse into the arguments of uplevel PHVs and aggregates,
    1789             :  * they will get copied to the appropriate subplan args list in the parent
    1790             :  * query with uplevel vars not replaced by Params, but only adjusted in level
    1791             :  * (see replace_outer_placeholdervar and replace_outer_agg).  That's exactly
    1792             :  * what we want for the vars of the parent level --- but if a PHV's or
    1793             :  * aggregate's argument contains any further-up variables, they have to be
    1794             :  * replaced with Params in their turn. That will happen when the parent level
    1795             :  * runs SS_replace_correlation_vars.  Therefore it must do so after expanding
    1796             :  * its sublinks to subplans.  And we don't want any steps in between, else
    1797             :  * those steps would never get applied to the argument expressions, either in
    1798             :  * the parent or the child level.
    1799             :  *
    1800             :  * Another fairly tricky thing going on here is the handling of SubLinks in
    1801             :  * the arguments of uplevel PHVs/aggregates.  Those are not touched inside the
    1802             :  * intermediate query level, either.  Instead, SS_process_sublinks recurses on
    1803             :  * them after copying the PHV or Aggref expression into the parent plan level
    1804             :  * (this is actually taken care of in build_subplan).
    1805             :  */
    1806             : Node *
    1807      123800 : SS_replace_correlation_vars(PlannerInfo *root, Node *expr)
    1808             : {
    1809             :     /* No setup needed for tree walk, so away we go */
    1810      123800 :     return replace_correlation_vars_mutator(expr, root);
    1811             : }
    1812             : 
    1813             : static Node *
    1814      952056 : replace_correlation_vars_mutator(Node *node, PlannerInfo *root)
    1815             : {
    1816      952056 :     if (node == NULL)
    1817       39652 :         return NULL;
    1818      912404 :     if (IsA(node, Var))
    1819             :     {
    1820      231742 :         if (((Var *) node)->varlevelsup > 0)
    1821       60102 :             return (Node *) replace_outer_var(root, (Var *) node);
    1822             :     }
    1823      852302 :     if (IsA(node, PlaceHolderVar))
    1824             :     {
    1825          20 :         if (((PlaceHolderVar *) node)->phlevelsup > 0)
    1826          20 :             return (Node *) replace_outer_placeholdervar(root,
    1827             :                                                          (PlaceHolderVar *) node);
    1828             :     }
    1829      852282 :     if (IsA(node, Aggref))
    1830             :     {
    1831       10984 :         if (((Aggref *) node)->agglevelsup > 0)
    1832          32 :             return (Node *) replace_outer_agg(root, (Aggref *) node);
    1833             :     }
    1834      852250 :     if (IsA(node, GroupingFunc))
    1835             :     {
    1836          32 :         if (((GroupingFunc *) node)->agglevelsup > 0)
    1837          16 :             return (Node *) replace_outer_grouping(root, (GroupingFunc *) node);
    1838             :     }
    1839      852234 :     return expression_tree_mutator(node,
    1840             :                                    replace_correlation_vars_mutator,
    1841             :                                    (void *) root);
    1842             : }
    1843             : 
    1844             : /*
    1845             :  * Expand SubLinks to SubPlans in the given expression.
    1846             :  *
    1847             :  * The isQual argument tells whether or not this expression is a WHERE/HAVING
    1848             :  * qualifier expression.  If it is, any sublinks appearing at top level need
    1849             :  * not distinguish FALSE from UNKNOWN return values.
    1850             :  */
    1851             : Node *
    1852      101056 : SS_process_sublinks(PlannerInfo *root, Node *expr, bool isQual)
    1853             : {
    1854             :     process_sublinks_context context;
    1855             : 
    1856      101056 :     context.root = root;
    1857      101056 :     context.isTopQual = isQual;
    1858      101056 :     return process_sublinks_mutator(expr, &context);
    1859             : }
    1860             : 
    1861             : static Node *
    1862     1590746 : process_sublinks_mutator(Node *node, process_sublinks_context *context)
    1863             : {
    1864             :     process_sublinks_context locContext;
    1865             : 
    1866     1590746 :     locContext.root = context->root;
    1867             : 
    1868     1590746 :     if (node == NULL)
    1869       82462 :         return NULL;
    1870     1508284 :     if (IsA(node, SubLink))
    1871             :     {
    1872       42950 :         SubLink    *sublink = (SubLink *) node;
    1873             :         Node       *testexpr;
    1874             : 
    1875             :         /*
    1876             :          * First, recursively process the lefthand-side expressions, if any.
    1877             :          * They're not top-level anymore.
    1878             :          */
    1879       42950 :         locContext.isTopQual = false;
    1880       42950 :         testexpr = process_sublinks_mutator(sublink->testexpr, &locContext);
    1881             : 
    1882             :         /*
    1883             :          * Now build the SubPlan node and make the expr to return.
    1884             :          */
    1885       85900 :         return make_subplan(context->root,
    1886       42950 :                             (Query *) sublink->subselect,
    1887             :                             sublink->subLinkType,
    1888             :                             sublink->subLinkId,
    1889             :                             testexpr,
    1890       42950 :                             context->isTopQual);
    1891             :     }
    1892             : 
    1893             :     /*
    1894             :      * Don't recurse into the arguments of an outer PHV or aggregate here. Any
    1895             :      * SubLinks in the arguments have to be dealt with at the outer query
    1896             :      * level; they'll be handled when build_subplan collects the PHV or Aggref
    1897             :      * into the arguments to be passed down to the current subplan.
    1898             :      */
    1899     1465334 :     if (IsA(node, PlaceHolderVar))
    1900             :     {
    1901          64 :         if (((PlaceHolderVar *) node)->phlevelsup > 0)
    1902           0 :             return node;
    1903             :     }
    1904     1465270 :     else if (IsA(node, Aggref))
    1905             :     {
    1906        5998 :         if (((Aggref *) node)->agglevelsup > 0)
    1907          12 :             return node;
    1908             :     }
    1909             : 
    1910             :     /*
    1911             :      * We should never see a SubPlan expression in the input (since this is
    1912             :      * the very routine that creates 'em to begin with).  We shouldn't find
    1913             :      * ourselves invoked directly on a Query, either.
    1914             :      */
    1915             :     Assert(!IsA(node, SubPlan));
    1916             :     Assert(!IsA(node, AlternativeSubPlan));
    1917             :     Assert(!IsA(node, Query));
    1918             : 
    1919             :     /*
    1920             :      * Because make_subplan() could return an AND or OR clause, we have to
    1921             :      * take steps to preserve AND/OR flatness of a qual.  We assume the input
    1922             :      * has been AND/OR flattened and so we need no recursion here.
    1923             :      *
    1924             :      * (Due to the coding here, we will not get called on the List subnodes of
    1925             :      * an AND; and the input is *not* yet in implicit-AND format.  So no check
    1926             :      * is needed for a bare List.)
    1927             :      *
    1928             :      * Anywhere within the top-level AND/OR clause structure, we can tell
    1929             :      * make_subplan() that NULL and FALSE are interchangeable.  So isTopQual
    1930             :      * propagates down in both cases.  (Note that this is unlike the meaning
    1931             :      * of "top level qual" used in most other places in Postgres.)
    1932             :      */
    1933     1465322 :     if (is_andclause(node))
    1934             :     {
    1935       21548 :         List       *newargs = NIL;
    1936             :         ListCell   *l;
    1937             : 
    1938             :         /* Still at qual top-level */
    1939       21548 :         locContext.isTopQual = context->isTopQual;
    1940             : 
    1941       73998 :         foreach(l, ((BoolExpr *) node)->args)
    1942             :         {
    1943             :             Node       *newarg;
    1944             : 
    1945       52450 :             newarg = process_sublinks_mutator(lfirst(l), &locContext);
    1946       52450 :             if (is_andclause(newarg))
    1947           0 :                 newargs = list_concat(newargs, ((BoolExpr *) newarg)->args);
    1948             :             else
    1949       52450 :                 newargs = lappend(newargs, newarg);
    1950             :         }
    1951       21548 :         return (Node *) make_andclause(newargs);
    1952             :     }
    1953             : 
    1954     1443774 :     if (is_orclause(node))
    1955             :     {
    1956        2770 :         List       *newargs = NIL;
    1957             :         ListCell   *l;
    1958             : 
    1959             :         /* Still at qual top-level */
    1960        2770 :         locContext.isTopQual = context->isTopQual;
    1961             : 
    1962        9058 :         foreach(l, ((BoolExpr *) node)->args)
    1963             :         {
    1964             :             Node       *newarg;
    1965             : 
    1966        6288 :             newarg = process_sublinks_mutator(lfirst(l), &locContext);
    1967        6288 :             if (is_orclause(newarg))
    1968           0 :                 newargs = list_concat(newargs, ((BoolExpr *) newarg)->args);
    1969             :             else
    1970        6288 :                 newargs = lappend(newargs, newarg);
    1971             :         }
    1972        2770 :         return (Node *) make_orclause(newargs);
    1973             :     }
    1974             : 
    1975             :     /*
    1976             :      * If we recurse down through anything other than an AND or OR node, we
    1977             :      * are definitely not at top qual level anymore.
    1978             :      */
    1979     1441004 :     locContext.isTopQual = false;
    1980             : 
    1981     1441004 :     return expression_tree_mutator(node,
    1982             :                                    process_sublinks_mutator,
    1983             :                                    (void *) &locContext);
    1984             : }
    1985             : 
    1986             : /*
    1987             :  * SS_identify_outer_params - identify the Params available from outer levels
    1988             :  *
    1989             :  * This must be run after SS_replace_correlation_vars and SS_process_sublinks
    1990             :  * processing is complete in a given query level as well as all of its
    1991             :  * descendant levels (which means it's most practical to do it at the end of
    1992             :  * processing the query level).  We compute the set of paramIds that outer
    1993             :  * levels will make available to this level+descendants, and record it in
    1994             :  * root->outer_params for use while computing extParam/allParam sets in final
    1995             :  * plan cleanup.  (We can't just compute it then, because the upper levels'
    1996             :  * plan_params lists are transient and will be gone by then.)
    1997             :  */
    1998             : void
    1999      288470 : SS_identify_outer_params(PlannerInfo *root)
    2000             : {
    2001             :     Bitmapset  *outer_params;
    2002             :     PlannerInfo *proot;
    2003             :     ListCell   *l;
    2004             : 
    2005             :     /*
    2006             :      * If no parameters have been assigned anywhere in the tree, we certainly
    2007             :      * don't need to do anything here.
    2008             :      */
    2009      288470 :     if (root->glob->paramExecTypes == NIL)
    2010      150342 :         return;
    2011             : 
    2012             :     /*
    2013             :      * Scan all query levels above this one to see which parameters are due to
    2014             :      * be available from them, either because lower query levels have
    2015             :      * requested them (via plan_params) or because they will be available from
    2016             :      * initPlans of those levels.
    2017             :      */
    2018      138128 :     outer_params = NULL;
    2019      180842 :     for (proot = root->parent_root; proot != NULL; proot = proot->parent_root)
    2020             :     {
    2021             :         /* Include ordinary Var/PHV/Aggref params */
    2022       96736 :         foreach(l, proot->plan_params)
    2023             :         {
    2024       54022 :             PlannerParamItem *pitem = (PlannerParamItem *) lfirst(l);
    2025             : 
    2026       54022 :             outer_params = bms_add_member(outer_params, pitem->paramId);
    2027             :         }
    2028             :         /* Include any outputs of outer-level initPlans */
    2029       43952 :         foreach(l, proot->init_plans)
    2030             :         {
    2031        1238 :             SubPlan    *initsubplan = (SubPlan *) lfirst(l);
    2032             :             ListCell   *l2;
    2033             : 
    2034        2476 :             foreach(l2, initsubplan->setParam)
    2035             :             {
    2036        1238 :                 outer_params = bms_add_member(outer_params, lfirst_int(l2));
    2037             :             }
    2038             :         }
    2039             :         /* Include worktable ID, if a recursive query is being planned */
    2040       42714 :         if (proot->wt_param_id >= 0)
    2041         736 :             outer_params = bms_add_member(outer_params, proot->wt_param_id);
    2042             :     }
    2043      138128 :     root->outer_params = outer_params;
    2044             : }
    2045             : 
    2046             : /*
    2047             :  * SS_charge_for_initplans - account for initplans in Path costs & parallelism
    2048             :  *
    2049             :  * If any initPlans have been created in the current query level, they will
    2050             :  * get attached to the Plan tree created from whichever Path we select from
    2051             :  * the given rel.  Increment all that rel's Paths' costs to account for them,
    2052             :  * and make sure the paths get marked as parallel-unsafe, since we can't
    2053             :  * currently transmit initPlans to parallel workers.
    2054             :  *
    2055             :  * This is separate from SS_attach_initplans because we might conditionally
    2056             :  * create more initPlans during create_plan(), depending on which Path we
    2057             :  * select.  However, Paths that would generate such initPlans are expected
    2058             :  * to have included their cost already.
    2059             :  */
    2060             : void
    2061      288470 : SS_charge_for_initplans(PlannerInfo *root, RelOptInfo *final_rel)
    2062             : {
    2063             :     Cost        initplan_cost;
    2064             :     ListCell   *lc;
    2065             : 
    2066             :     /* Nothing to do if no initPlans */
    2067      288470 :     if (root->init_plans == NIL)
    2068      279708 :         return;
    2069             : 
    2070             :     /*
    2071             :      * Compute the cost increment just once, since it will be the same for all
    2072             :      * Paths.  We assume each initPlan gets run once during top plan startup.
    2073             :      * This is a conservative overestimate, since in fact an initPlan might be
    2074             :      * executed later than plan startup, or even not at all.
    2075             :      */
    2076        8762 :     initplan_cost = 0;
    2077       17874 :     foreach(lc, root->init_plans)
    2078             :     {
    2079        9112 :         SubPlan    *initsubplan = (SubPlan *) lfirst(lc);
    2080             : 
    2081        9112 :         initplan_cost += initsubplan->startup_cost + initsubplan->per_call_cost;
    2082             :     }
    2083             : 
    2084             :     /*
    2085             :      * Now adjust the costs and parallel_safe flags.
    2086             :      */
    2087       17560 :     foreach(lc, final_rel->pathlist)
    2088             :     {
    2089        8798 :         Path       *path = (Path *) lfirst(lc);
    2090             : 
    2091        8798 :         path->startup_cost += initplan_cost;
    2092        8798 :         path->total_cost += initplan_cost;
    2093        8798 :         path->parallel_safe = false;
    2094             :     }
    2095             : 
    2096             :     /*
    2097             :      * Forget about any partial paths and clear consider_parallel, too;
    2098             :      * they're not usable if we attached an initPlan.
    2099             :      */
    2100        8762 :     final_rel->partial_pathlist = NIL;
    2101        8762 :     final_rel->consider_parallel = false;
    2102             : 
    2103             :     /* We needn't do set_cheapest() here, caller will do it */
    2104             : }
    2105             : 
    2106             : /*
    2107             :  * SS_attach_initplans - attach initplans to topmost plan node
    2108             :  *
    2109             :  * Attach any initplans created in the current query level to the specified
    2110             :  * plan node, which should normally be the topmost node for the query level.
    2111             :  * (In principle the initPlans could go in any node at or above where they're
    2112             :  * referenced; but there seems no reason to put them any lower than the
    2113             :  * topmost node, so we don't bother to track exactly where they came from.)
    2114             :  * We do not touch the plan node's cost; the initplans should have been
    2115             :  * accounted for in path costing.
    2116             :  */
    2117             : void
    2118      287824 : SS_attach_initplans(PlannerInfo *root, Plan *plan)
    2119             : {
    2120      287824 :     plan->initPlan = root->init_plans;
    2121      287824 : }
    2122             : 
    2123             : /*
    2124             :  * SS_finalize_plan - do final parameter processing for a completed Plan.
    2125             :  *
    2126             :  * This recursively computes the extParam and allParam sets for every Plan
    2127             :  * node in the given plan tree.  (Oh, and RangeTblFunction.funcparams too.)
    2128             :  *
    2129             :  * We assume that SS_finalize_plan has already been run on any initplans or
    2130             :  * subplans the plan tree could reference.
    2131             :  */
    2132             : void
    2133      151410 : SS_finalize_plan(PlannerInfo *root, Plan *plan)
    2134             : {
    2135             :     /* No setup needed, just recurse through plan tree. */
    2136      151410 :     (void) finalize_plan(root, plan, -1, root->outer_params, NULL);
    2137      151410 : }
    2138             : 
    2139             : /*
    2140             :  * Recursive processing of all nodes in the plan tree
    2141             :  *
    2142             :  * gather_param is the rescan_param of an ancestral Gather/GatherMerge,
    2143             :  * or -1 if there is none.
    2144             :  *
    2145             :  * valid_params is the set of param IDs supplied by outer plan levels
    2146             :  * that are valid to reference in this plan node or its children.
    2147             :  *
    2148             :  * scan_params is a set of param IDs to force scan plan nodes to reference.
    2149             :  * This is for EvalPlanQual support, and is always NULL at the top of the
    2150             :  * recursion.
    2151             :  *
    2152             :  * The return value is the computed allParam set for the given Plan node.
    2153             :  * This is just an internal notational convenience: we can add a child
    2154             :  * plan's allParams to the set of param IDs of interest to this level
    2155             :  * in the same statement that recurses to that child.
    2156             :  *
    2157             :  * Do not scribble on caller's values of valid_params or scan_params!
    2158             :  *
    2159             :  * Note: although we attempt to deal with initPlans anywhere in the tree, the
    2160             :  * logic is not really right.  The problem is that a plan node might return an
    2161             :  * output Param of its initPlan as a targetlist item, in which case it's valid
    2162             :  * for the parent plan level to reference that same Param; the parent's usage
    2163             :  * will be converted into a Var referencing the child plan node by setrefs.c.
    2164             :  * But this function would see the parent's reference as out of scope and
    2165             :  * complain about it.  For now, this does not matter because the planner only
    2166             :  * attaches initPlans to the topmost plan node in a query level, so the case
    2167             :  * doesn't arise.  If we ever merge this processing into setrefs.c, maybe it
    2168             :  * can be handled more cleanly.
    2169             :  */
    2170             : static Bitmapset *
    2171      989962 : finalize_plan(PlannerInfo *root, Plan *plan,
    2172             :               int gather_param,
    2173             :               Bitmapset *valid_params,
    2174             :               Bitmapset *scan_params)
    2175             : {
    2176             :     finalize_primnode_context context;
    2177             :     int         locally_added_param;
    2178             :     Bitmapset  *nestloop_params;
    2179             :     Bitmapset  *initExtParam;
    2180             :     Bitmapset  *initSetParam;
    2181             :     Bitmapset  *child_params;
    2182             :     ListCell   *l;
    2183             : 
    2184      989962 :     if (plan == NULL)
    2185      611032 :         return NULL;
    2186             : 
    2187      378930 :     context.root = root;
    2188      378930 :     context.paramids = NULL;    /* initialize set to empty */
    2189      378930 :     locally_added_param = -1;   /* there isn't one */
    2190      378930 :     nestloop_params = NULL;     /* there aren't any */
    2191             : 
    2192             :     /*
    2193             :      * Examine any initPlans to determine the set of external params they
    2194             :      * reference and the set of output params they supply.  (We assume
    2195             :      * SS_finalize_plan was run on them already.)
    2196             :      */
    2197      378930 :     initExtParam = initSetParam = NULL;
    2198      388402 :     foreach(l, plan->initPlan)
    2199             :     {
    2200        9472 :         SubPlan    *initsubplan = (SubPlan *) lfirst(l);
    2201        9472 :         Plan       *initplan = planner_subplan_get_plan(root, initsubplan);
    2202             :         ListCell   *l2;
    2203             : 
    2204        9472 :         initExtParam = bms_add_members(initExtParam, initplan->extParam);
    2205       18960 :         foreach(l2, initsubplan->setParam)
    2206             :         {
    2207        9488 :             initSetParam = bms_add_member(initSetParam, lfirst_int(l2));
    2208             :         }
    2209             :     }
    2210             : 
    2211             :     /* Any setParams are validly referenceable in this node and children */
    2212      378930 :     if (initSetParam)
    2213        9090 :         valid_params = bms_union(valid_params, initSetParam);
    2214             : 
    2215             :     /*
    2216             :      * When we call finalize_primnode, context.paramids sets are automatically
    2217             :      * merged together.  But when recursing to self, we have to do it the hard
    2218             :      * way.  We want the paramids set to include params in subplans as well as
    2219             :      * at this level.
    2220             :      */
    2221             : 
    2222             :     /* Find params in targetlist and qual */
    2223      378930 :     finalize_primnode((Node *) plan->targetlist, &context);
    2224      378930 :     finalize_primnode((Node *) plan->qual, &context);
    2225             : 
    2226             :     /*
    2227             :      * If it's a parallel-aware scan node, mark it as dependent on the parent
    2228             :      * Gather/GatherMerge's rescan Param.
    2229             :      */
    2230      378930 :     if (plan->parallel_aware)
    2231             :     {
    2232        1644 :         if (gather_param < 0)
    2233           0 :             elog(ERROR, "parallel-aware plan node is not below a Gather");
    2234        1644 :         context.paramids =
    2235        1644 :             bms_add_member(context.paramids, gather_param);
    2236             :     }
    2237             : 
    2238             :     /* Check additional node-type-specific fields */
    2239      378930 :     switch (nodeTag(plan))
    2240             :     {
    2241             :         case T_Result:
    2242       46672 :             finalize_primnode(((Result *) plan)->resconstantqual,
    2243             :                               &context);
    2244       46672 :             break;
    2245             : 
    2246             :         case T_SeqScan:
    2247       62674 :             context.paramids = bms_add_members(context.paramids, scan_params);
    2248       62674 :             break;
    2249             : 
    2250             :         case T_SampleScan:
    2251          36 :             finalize_primnode((Node *) ((SampleScan *) plan)->tablesample,
    2252             :                               &context);
    2253          36 :             context.paramids = bms_add_members(context.paramids, scan_params);
    2254          36 :             break;
    2255             : 
    2256             :         case T_IndexScan:
    2257       53736 :             finalize_primnode((Node *) ((IndexScan *) plan)->indexqual,
    2258             :                               &context);
    2259       53736 :             finalize_primnode((Node *) ((IndexScan *) plan)->indexorderby,
    2260             :                               &context);
    2261             : 
    2262             :             /*
    2263             :              * we need not look at indexqualorig, since it will have the same
    2264             :              * param references as indexqual.  Likewise, we can ignore
    2265             :              * indexorderbyorig.
    2266             :              */
    2267       53736 :             context.paramids = bms_add_members(context.paramids, scan_params);
    2268       53736 :             break;
    2269             : 
    2270             :         case T_IndexOnlyScan:
    2271        1940 :             finalize_primnode((Node *) ((IndexOnlyScan *) plan)->indexqual,
    2272             :                               &context);
    2273        1940 :             finalize_primnode((Node *) ((IndexOnlyScan *) plan)->indexorderby,
    2274             :                               &context);
    2275             : 
    2276             :             /*
    2277             :              * we need not look at indextlist, since it cannot contain Params.
    2278             :              */
    2279        1940 :             context.paramids = bms_add_members(context.paramids, scan_params);
    2280        1940 :             break;
    2281             : 
    2282             :         case T_BitmapIndexScan:
    2283        7864 :             finalize_primnode((Node *) ((BitmapIndexScan *) plan)->indexqual,
    2284             :                               &context);
    2285             : 
    2286             :             /*
    2287             :              * we need not look at indexqualorig, since it will have the same
    2288             :              * param references as indexqual.
    2289             :              */
    2290        7864 :             break;
    2291             : 
    2292             :         case T_BitmapHeapScan:
    2293        7800 :             finalize_primnode((Node *) ((BitmapHeapScan *) plan)->bitmapqualorig,
    2294             :                               &context);
    2295        7800 :             context.paramids = bms_add_members(context.paramids, scan_params);
    2296        7800 :             break;
    2297             : 
    2298             :         case T_TidScan:
    2299         358 :             finalize_primnode((Node *) ((TidScan *) plan)->tidquals,
    2300             :                               &context);
    2301         358 :             context.paramids = bms_add_members(context.paramids, scan_params);
    2302         358 :             break;
    2303             : 
    2304             :         case T_SubqueryScan:
    2305             :             {
    2306        4224 :                 SubqueryScan *sscan = (SubqueryScan *) plan;
    2307             :                 RelOptInfo *rel;
    2308             :                 Bitmapset  *subquery_params;
    2309             : 
    2310             :                 /* We must run finalize_plan on the subquery */
    2311        4224 :                 rel = find_base_rel(root, sscan->scan.scanrelid);
    2312        4224 :                 subquery_params = rel->subroot->outer_params;
    2313        4224 :                 if (gather_param >= 0)
    2314           8 :                     subquery_params = bms_add_member(bms_copy(subquery_params),
    2315             :                                                      gather_param);
    2316        4224 :                 finalize_plan(rel->subroot, sscan->subplan, gather_param,
    2317             :                               subquery_params, NULL);
    2318             : 
    2319             :                 /* Now we can add its extParams to the parent's params */
    2320        4224 :                 context.paramids = bms_add_members(context.paramids,
    2321        4224 :                                                    sscan->subplan->extParam);
    2322             :                 /* We need scan_params too, though */
    2323        4224 :                 context.paramids = bms_add_members(context.paramids,
    2324             :                                                    scan_params);
    2325             :             }
    2326        4224 :             break;
    2327             : 
    2328             :         case T_FunctionScan:
    2329             :             {
    2330       21590 :                 FunctionScan *fscan = (FunctionScan *) plan;
    2331             :                 ListCell   *lc;
    2332             : 
    2333             :                 /*
    2334             :                  * Call finalize_primnode independently on each function
    2335             :                  * expression, so that we can record which params are
    2336             :                  * referenced in each, in order to decide which need
    2337             :                  * re-evaluating during rescan.
    2338             :                  */
    2339       43196 :                 foreach(lc, fscan->functions)
    2340             :                 {
    2341       21606 :                     RangeTblFunction *rtfunc = (RangeTblFunction *) lfirst(lc);
    2342             :                     finalize_primnode_context funccontext;
    2343             : 
    2344       21606 :                     funccontext = context;
    2345       21606 :                     funccontext.paramids = NULL;
    2346             : 
    2347       21606 :                     finalize_primnode(rtfunc->funcexpr, &funccontext);
    2348             : 
    2349             :                     /* remember results for execution */
    2350       21606 :                     rtfunc->funcparams = funccontext.paramids;
    2351             : 
    2352             :                     /* add the function's params to the overall set */
    2353       21606 :                     context.paramids = bms_add_members(context.paramids,
    2354       21606 :                                                        funccontext.paramids);
    2355             :                 }
    2356             : 
    2357       21590 :                 context.paramids = bms_add_members(context.paramids,
    2358             :                                                    scan_params);
    2359             :             }
    2360       21590 :             break;
    2361             : 
    2362             :         case T_TableFuncScan:
    2363          96 :             finalize_primnode((Node *) ((TableFuncScan *) plan)->tablefunc,
    2364             :                               &context);
    2365          96 :             context.paramids = bms_add_members(context.paramids, scan_params);
    2366          96 :             break;
    2367             : 
    2368             :         case T_ValuesScan:
    2369        2636 :             finalize_primnode((Node *) ((ValuesScan *) plan)->values_lists,
    2370             :                               &context);
    2371        2636 :             context.paramids = bms_add_members(context.paramids, scan_params);
    2372        2636 :             break;
    2373             : 
    2374             :         case T_CteScan:
    2375             :             {
    2376             :                 /*
    2377             :                  * You might think we should add the node's cteParam to
    2378             :                  * paramids, but we shouldn't because that param is just a
    2379             :                  * linkage mechanism for multiple CteScan nodes for the same
    2380             :                  * CTE; it is never used for changed-param signaling.  What we
    2381             :                  * have to do instead is to find the referenced CTE plan and
    2382             :                  * incorporate its external paramids, so that the correct
    2383             :                  * things will happen if the CTE references outer-level
    2384             :                  * variables.  See test cases for bug #4902.  (We assume
    2385             :                  * SS_finalize_plan was run on the CTE plan already.)
    2386             :                  */
    2387         868 :                 int         plan_id = ((CteScan *) plan)->ctePlanId;
    2388             :                 Plan       *cteplan;
    2389             : 
    2390             :                 /* so, do this ... */
    2391         868 :                 if (plan_id < 1 || plan_id > list_length(root->glob->subplans))
    2392           0 :                     elog(ERROR, "could not find plan for CteScan referencing plan ID %d",
    2393             :                          plan_id);
    2394         868 :                 cteplan = (Plan *) list_nth(root->glob->subplans, plan_id - 1);
    2395         868 :                 context.paramids =
    2396         868 :                     bms_add_members(context.paramids, cteplan->extParam);
    2397             : 
    2398             : #ifdef NOT_USED
    2399             :                 /* ... but not this */
    2400             :                 context.paramids =
    2401             :                     bms_add_member(context.paramids,
    2402             :                                    ((CteScan *) plan)->cteParam);
    2403             : #endif
    2404             : 
    2405         868 :                 context.paramids = bms_add_members(context.paramids,
    2406             :                                                    scan_params);
    2407             :             }
    2408         868 :             break;
    2409             : 
    2410             :         case T_WorkTableScan:
    2411         326 :             context.paramids =
    2412         326 :                 bms_add_member(context.paramids,
    2413             :                                ((WorkTableScan *) plan)->wtParam);
    2414         326 :             context.paramids = bms_add_members(context.paramids, scan_params);
    2415         326 :             break;
    2416             : 
    2417             :         case T_NamedTuplestoreScan:
    2418         212 :             context.paramids = bms_add_members(context.paramids, scan_params);
    2419         212 :             break;
    2420             : 
    2421             :         case T_ForeignScan:
    2422             :             {
    2423         458 :                 ForeignScan *fscan = (ForeignScan *) plan;
    2424             : 
    2425         458 :                 finalize_primnode((Node *) fscan->fdw_exprs,
    2426             :                                   &context);
    2427         458 :                 finalize_primnode((Node *) fscan->fdw_recheck_quals,
    2428             :                                   &context);
    2429             : 
    2430             :                 /* We assume fdw_scan_tlist cannot contain Params */
    2431         458 :                 context.paramids = bms_add_members(context.paramids,
    2432             :                                                    scan_params);
    2433             :             }
    2434         458 :             break;
    2435             : 
    2436             :         case T_CustomScan:
    2437             :             {
    2438           0 :                 CustomScan *cscan = (CustomScan *) plan;
    2439             :                 ListCell   *lc;
    2440             : 
    2441           0 :                 finalize_primnode((Node *) cscan->custom_exprs,
    2442             :                                   &context);
    2443             :                 /* We assume custom_scan_tlist cannot contain Params */
    2444           0 :                 context.paramids =
    2445           0 :                     bms_add_members(context.paramids, scan_params);
    2446             : 
    2447             :                 /* child nodes if any */
    2448           0 :                 foreach(lc, cscan->custom_plans)
    2449             :                 {
    2450           0 :                     context.paramids =
    2451           0 :                         bms_add_members(context.paramids,
    2452           0 :                                         finalize_plan(root,
    2453           0 :                                                       (Plan *) lfirst(lc),
    2454             :                                                       gather_param,
    2455             :                                                       valid_params,
    2456             :                                                       scan_params));
    2457             :                 }
    2458             :             }
    2459           0 :             break;
    2460             : 
    2461             :         case T_ModifyTable:
    2462             :             {
    2463       69316 :                 ModifyTable *mtplan = (ModifyTable *) plan;
    2464             :                 ListCell   *l;
    2465             : 
    2466             :                 /* Force descendant scan nodes to reference epqParam */
    2467       69316 :                 locally_added_param = mtplan->epqParam;
    2468       69316 :                 valid_params = bms_add_member(bms_copy(valid_params),
    2469             :                                               locally_added_param);
    2470       69316 :                 scan_params = bms_add_member(bms_copy(scan_params),
    2471             :                                              locally_added_param);
    2472       69316 :                 finalize_primnode((Node *) mtplan->returningLists,
    2473             :                                   &context);
    2474       69316 :                 finalize_primnode((Node *) mtplan->onConflictSet,
    2475             :                                   &context);
    2476       69316 :                 finalize_primnode((Node *) mtplan->onConflictWhere,
    2477             :                                   &context);
    2478             :                 /* exclRelTlist contains only Vars, doesn't need examination */
    2479      139672 :                 foreach(l, mtplan->plans)
    2480             :                 {
    2481       70356 :                     context.paramids =
    2482       70356 :                         bms_add_members(context.paramids,
    2483       70356 :                                         finalize_plan(root,
    2484       70356 :                                                       (Plan *) lfirst(l),
    2485             :                                                       gather_param,
    2486             :                                                       valid_params,
    2487             :                                                       scan_params));
    2488             :                 }
    2489             :             }
    2490       69316 :             break;
    2491             : 
    2492             :         case T_Append:
    2493             :             {
    2494             :                 ListCell   *l;
    2495             : 
    2496        7804 :                 foreach(l, ((Append *) plan)->appendplans)
    2497             :                 {
    2498        5780 :                     context.paramids =
    2499        5780 :                         bms_add_members(context.paramids,
    2500        5780 :                                         finalize_plan(root,
    2501        5780 :                                                       (Plan *) lfirst(l),
    2502             :                                                       gather_param,
    2503             :                                                       valid_params,
    2504             :                                                       scan_params));
    2505             :                 }
    2506             :             }
    2507        2024 :             break;
    2508             : 
    2509             :         case T_MergeAppend:
    2510             :             {
    2511             :                 ListCell   *l;
    2512             : 
    2513         264 :                 foreach(l, ((MergeAppend *) plan)->mergeplans)
    2514             :                 {
    2515         204 :                     context.paramids =
    2516         204 :                         bms_add_members(context.paramids,
    2517         204 :                                         finalize_plan(root,
    2518         204 :                                                       (Plan *) lfirst(l),
    2519             :                                                       gather_param,
    2520             :                                                       valid_params,
    2521             :                                                       scan_params));
    2522             :                 }
    2523             :             }
    2524          60 :             break;
    2525             : 
    2526             :         case T_BitmapAnd:
    2527             :             {
    2528             :                 ListCell   *l;
    2529             : 
    2530          96 :                 foreach(l, ((BitmapAnd *) plan)->bitmapplans)
    2531             :                 {
    2532          64 :                     context.paramids =
    2533          64 :                         bms_add_members(context.paramids,
    2534          64 :                                         finalize_plan(root,
    2535          64 :                                                       (Plan *) lfirst(l),
    2536             :                                                       gather_param,
    2537             :                                                       valid_params,
    2538             :                                                       scan_params));
    2539             :                 }
    2540             :             }
    2541          32 :             break;
    2542             : 
    2543             :         case T_BitmapOr:
    2544             :             {
    2545             :                 ListCell   *l;
    2546             : 
    2547          96 :                 foreach(l, ((BitmapOr *) plan)->bitmapplans)
    2548             :                 {
    2549          64 :                     context.paramids =
    2550          64 :                         bms_add_members(context.paramids,
    2551          64 :                                         finalize_plan(root,
    2552          64 :                                                       (Plan *) lfirst(l),
    2553             :                                                       gather_param,
    2554             :                                                       valid_params,
    2555             :                                                       scan_params));
    2556             :                 }
    2557             :             }
    2558          32 :             break;
    2559             : 
    2560             :         case T_NestLoop:
    2561             :             {
    2562             :                 ListCell   *l;
    2563             : 
    2564       24830 :                 finalize_primnode((Node *) ((Join *) plan)->joinqual,
    2565             :                                   &context);
    2566             :                 /* collect set of params that will be passed to right child */
    2567       41966 :                 foreach(l, ((NestLoop *) plan)->nestParams)
    2568             :                 {
    2569       17136 :                     NestLoopParam *nlp = (NestLoopParam *) lfirst(l);
    2570             : 
    2571       17136 :                     nestloop_params = bms_add_member(nestloop_params,
    2572             :                                                      nlp->paramno);
    2573             :                 }
    2574             :             }
    2575       24830 :             break;
    2576             : 
    2577             :         case T_MergeJoin:
    2578         904 :             finalize_primnode((Node *) ((Join *) plan)->joinqual,
    2579             :                               &context);
    2580         904 :             finalize_primnode((Node *) ((MergeJoin *) plan)->mergeclauses,
    2581             :                               &context);
    2582         904 :             break;
    2583             : 
    2584             :         case T_HashJoin:
    2585       15196 :             finalize_primnode((Node *) ((Join *) plan)->joinqual,
    2586             :                               &context);
    2587       15196 :             finalize_primnode((Node *) ((HashJoin *) plan)->hashclauses,
    2588             :                               &context);
    2589       15196 :             break;
    2590             : 
    2591             :         case T_Limit:
    2592        1572 :             finalize_primnode(((Limit *) plan)->limitOffset,
    2593             :                               &context);
    2594        1572 :             finalize_primnode(((Limit *) plan)->limitCount,
    2595             :                               &context);
    2596        1572 :             break;
    2597             : 
    2598             :         case T_RecursiveUnion:
    2599             :             /* child nodes are allowed to reference wtParam */
    2600         326 :             locally_added_param = ((RecursiveUnion *) plan)->wtParam;
    2601         326 :             valid_params = bms_add_member(bms_copy(valid_params),
    2602             :                                           locally_added_param);
    2603             :             /* wtParam does *not* get added to scan_params */
    2604         326 :             break;
    2605             : 
    2606             :         case T_LockRows:
    2607             :             /* Force descendant scan nodes to reference epqParam */
    2608        4718 :             locally_added_param = ((LockRows *) plan)->epqParam;
    2609        4718 :             valid_params = bms_add_member(bms_copy(valid_params),
    2610             :                                           locally_added_param);
    2611        4718 :             scan_params = bms_add_member(bms_copy(scan_params),
    2612             :                                          locally_added_param);
    2613        4718 :             break;
    2614             : 
    2615             :         case T_Agg:
    2616             :             {
    2617       12582 :                 Agg        *agg = (Agg *) plan;
    2618             : 
    2619             :                 /*
    2620             :                  * AGG_HASHED plans need to know which Params are referenced
    2621             :                  * in aggregate calls.  Do a separate scan to identify them.
    2622             :                  */
    2623       12582 :                 if (agg->aggstrategy == AGG_HASHED)
    2624             :                 {
    2625             :                     finalize_primnode_context aggcontext;
    2626             : 
    2627         786 :                     aggcontext.root = root;
    2628         786 :                     aggcontext.paramids = NULL;
    2629         786 :                     finalize_agg_primnode((Node *) agg->plan.targetlist,
    2630             :                                           &aggcontext);
    2631         786 :                     finalize_agg_primnode((Node *) agg->plan.qual,
    2632             :                                           &aggcontext);
    2633         786 :                     agg->aggParams = aggcontext.paramids;
    2634             :                 }
    2635             :             }
    2636       12582 :             break;
    2637             : 
    2638             :         case T_WindowAgg:
    2639          36 :             finalize_primnode(((WindowAgg *) plan)->startOffset,
    2640             :                               &context);
    2641          36 :             finalize_primnode(((WindowAgg *) plan)->endOffset,
    2642             :                               &context);
    2643          36 :             break;
    2644             : 
    2645             :         case T_Gather:
    2646             :             /* child nodes are allowed to reference rescan_param, if any */
    2647         524 :             locally_added_param = ((Gather *) plan)->rescan_param;
    2648         524 :             if (locally_added_param >= 0)
    2649             :             {
    2650         524 :                 valid_params = bms_add_member(bms_copy(valid_params),
    2651             :                                               locally_added_param);
    2652             : 
    2653             :                 /*
    2654             :                  * We currently don't support nested Gathers.  The issue so
    2655             :                  * far as this function is concerned would be how to identify
    2656             :                  * which child nodes depend on which Gather.
    2657             :                  */
    2658             :                 Assert(gather_param < 0);
    2659             :                 /* Pass down rescan_param to child parallel-aware nodes */
    2660         524 :                 gather_param = locally_added_param;
    2661             :             }
    2662             :             /* rescan_param does *not* get added to scan_params */
    2663         524 :             break;
    2664             : 
    2665             :         case T_GatherMerge:
    2666             :             /* child nodes are allowed to reference rescan_param, if any */
    2667         136 :             locally_added_param = ((GatherMerge *) plan)->rescan_param;
    2668         136 :             if (locally_added_param >= 0)
    2669             :             {
    2670         136 :                 valid_params = bms_add_member(bms_copy(valid_params),
    2671             :                                               locally_added_param);
    2672             : 
    2673             :                 /*
    2674             :                  * We currently don't support nested Gathers.  The issue so
    2675             :                  * far as this function is concerned would be how to identify
    2676             :                  * which child nodes depend on which Gather.
    2677             :                  */
    2678             :                 Assert(gather_param < 0);
    2679             :                 /* Pass down rescan_param to child parallel-aware nodes */
    2680         136 :                 gather_param = locally_added_param;
    2681             :             }
    2682             :             /* rescan_param does *not* get added to scan_params */
    2683         136 :             break;
    2684             : 
    2685             :         case T_ProjectSet:
    2686             :         case T_Hash:
    2687             :         case T_Material:
    2688             :         case T_Sort:
    2689             :         case T_Unique:
    2690             :         case T_SetOp:
    2691             :         case T_Group:
    2692             :             /* no node-type-specific fields need fixing */
    2693       35152 :             break;
    2694             : 
    2695             :         default:
    2696           0 :             elog(ERROR, "unrecognized node type: %d",
    2697             :                  (int) nodeTag(plan));
    2698             :     }
    2699             : 
    2700             :     /* Process left and right child plans, if any */
    2701      378930 :     child_params = finalize_plan(root,
    2702      378930 :                                  plan->lefttree,
    2703             :                                  gather_param,
    2704             :                                  valid_params,
    2705             :                                  scan_params);
    2706      378930 :     context.paramids = bms_add_members(context.paramids, child_params);
    2707             : 
    2708      378930 :     if (nestloop_params)
    2709             :     {
    2710             :         /* right child can reference nestloop_params as well as valid_params */
    2711       32980 :         child_params = finalize_plan(root,
    2712       16490 :                                      plan->righttree,
    2713             :                                      gather_param,
    2714             :                                      bms_union(nestloop_params, valid_params),
    2715             :                                      scan_params);
    2716             :         /* ... and they don't count as parameters used at my level */
    2717       16490 :         child_params = bms_difference(child_params, nestloop_params);
    2718       16490 :         bms_free(nestloop_params);
    2719             :     }
    2720             :     else
    2721             :     {
    2722             :         /* easy case */
    2723      362440 :         child_params = finalize_plan(root,
    2724      362440 :                                      plan->righttree,
    2725             :                                      gather_param,
    2726             :                                      valid_params,
    2727             :                                      scan_params);
    2728             :     }
    2729      378930 :     context.paramids = bms_add_members(context.paramids, child_params);
    2730             : 
    2731             :     /*
    2732             :      * Any locally generated parameter doesn't count towards its generating
    2733             :      * plan node's external dependencies.  (Note: if we changed valid_params
    2734             :      * and/or scan_params, we leak those bitmapsets; not worth the notational
    2735             :      * trouble to clean them up.)
    2736             :      */
    2737      378930 :     if (locally_added_param >= 0)
    2738             :     {
    2739       75020 :         context.paramids = bms_del_member(context.paramids,
    2740             :                                           locally_added_param);
    2741             :     }
    2742             : 
    2743             :     /* Now we have all the paramids referenced in this node and children */
    2744             : 
    2745      378930 :     if (!bms_is_subset(context.paramids, valid_params))
    2746           0 :         elog(ERROR, "plan should not reference subplan's variable");
    2747             : 
    2748             :     /*
    2749             :      * The plan node's allParam and extParam fields should include all its
    2750             :      * referenced paramids, plus contributions from any child initPlans.
    2751             :      * However, any setParams of the initPlans should not be present in the
    2752             :      * parent node's extParams, only in its allParams.  (It's possible that
    2753             :      * some initPlans have extParams that are setParams of other initPlans.)
    2754             :      */
    2755             : 
    2756             :     /* allParam must include initplans' extParams and setParams */
    2757      378930 :     plan->allParam = bms_union(context.paramids, initExtParam);
    2758      378930 :     plan->allParam = bms_add_members(plan->allParam, initSetParam);
    2759             :     /* extParam must include any initplan extParams */
    2760      378930 :     plan->extParam = bms_union(context.paramids, initExtParam);
    2761             :     /* but not any initplan setParams */
    2762      378930 :     plan->extParam = bms_del_members(plan->extParam, initSetParam);
    2763             : 
    2764             :     /*
    2765             :      * For speed at execution time, make sure extParam/allParam are actually
    2766             :      * NULL if they are empty sets.
    2767             :      */
    2768      378930 :     if (bms_is_empty(plan->extParam))
    2769      230096 :         plan->extParam = NULL;
    2770      378930 :     if (bms_is_empty(plan->allParam))
    2771      221150 :         plan->allParam = NULL;
    2772             : 
    2773      378930 :     return plan->allParam;
    2774             : }
    2775             : 
    2776             : /*
    2777             :  * finalize_primnode: add IDs of all PARAM_EXEC params appearing in the given
    2778             :  * expression tree to the result set.
    2779             :  */
    2780             : static bool
    2781     6817412 : finalize_primnode(Node *node, finalize_primnode_context *context)
    2782             : {
    2783     6817412 :     if (node == NULL)
    2784      832516 :         return false;
    2785     5984896 :     if (IsA(node, Param))
    2786             :     {
    2787       91090 :         if (((Param *) node)->paramkind == PARAM_EXEC)
    2788             :         {
    2789       89538 :             int         paramid = ((Param *) node)->paramid;
    2790             : 
    2791       89538 :             context->paramids = bms_add_member(context->paramids, paramid);
    2792             :         }
    2793       91090 :         return false;           /* no more to do here */
    2794             :     }
    2795     5893806 :     if (IsA(node, SubPlan))
    2796             :     {
    2797       43914 :         SubPlan    *subplan = (SubPlan *) node;
    2798       43914 :         Plan       *plan = planner_subplan_get_plan(context->root, subplan);
    2799             :         ListCell   *lc;
    2800             :         Bitmapset  *subparamids;
    2801             : 
    2802             :         /* Recurse into the testexpr, but not into the Plan */
    2803       43914 :         finalize_primnode(subplan->testexpr, context);
    2804             : 
    2805             :         /*
    2806             :          * Remove any param IDs of output parameters of the subplan that were
    2807             :          * referenced in the testexpr.  These are not interesting for
    2808             :          * parameter change signaling since we always re-evaluate the subplan.
    2809             :          * Note that this wouldn't work too well if there might be uses of the
    2810             :          * same param IDs elsewhere in the plan, but that can't happen because
    2811             :          * generate_new_exec_param never tries to merge params.
    2812             :          */
    2813       45178 :         foreach(lc, subplan->paramIds)
    2814             :         {
    2815        1264 :             context->paramids = bms_del_member(context->paramids,
    2816             :                                                lfirst_int(lc));
    2817             :         }
    2818             : 
    2819             :         /* Also examine args list */
    2820       43914 :         finalize_primnode((Node *) subplan->args, context);
    2821             : 
    2822             :         /*
    2823             :          * Add params needed by the subplan to paramids, but excluding those
    2824             :          * we will pass down to it.  (We assume SS_finalize_plan was run on
    2825             :          * the subplan already.)
    2826             :          */
    2827       43914 :         subparamids = bms_copy(plan->extParam);
    2828      106532 :         foreach(lc, subplan->parParam)
    2829             :         {
    2830       62618 :             subparamids = bms_del_member(subparamids, lfirst_int(lc));
    2831             :         }
    2832       43914 :         context->paramids = bms_join(context->paramids, subparamids);
    2833             : 
    2834       43914 :         return false;           /* no more to do here */
    2835             :     }
    2836     5849892 :     return expression_tree_walker(node, finalize_primnode,
    2837             :                                   (void *) context);
    2838             : }
    2839             : 
    2840             : /*
    2841             :  * finalize_agg_primnode: find all Aggref nodes in the given expression tree,
    2842             :  * and add IDs of all PARAM_EXEC params appearing within their aggregated
    2843             :  * arguments to the result set.
    2844             :  */
    2845             : static bool
    2846        5364 : finalize_agg_primnode(Node *node, finalize_primnode_context *context)
    2847             : {
    2848        5364 :     if (node == NULL)
    2849         754 :         return false;
    2850        4610 :     if (IsA(node, Aggref))
    2851             :     {
    2852         616 :         Aggref     *agg = (Aggref *) node;
    2853             : 
    2854             :         /* we should not consider the direct arguments, if any */
    2855         616 :         finalize_primnode((Node *) agg->args, context);
    2856         616 :         finalize_primnode((Node *) agg->aggfilter, context);
    2857         616 :         return false;           /* there can't be any Aggrefs below here */
    2858             :     }
    2859        3994 :     return expression_tree_walker(node, finalize_agg_primnode,
    2860             :                                   (void *) context);
    2861             : }
    2862             : 
    2863             : /*
    2864             :  * SS_make_initplan_output_param - make a Param for an initPlan's output
    2865             :  *
    2866             :  * The plan is expected to return a scalar value of the given type/collation.
    2867             :  *
    2868             :  * Note that in some cases the initplan may not ever appear in the finished
    2869             :  * plan tree.  If that happens, we'll have wasted a PARAM_EXEC slot, which
    2870             :  * is no big deal.
    2871             :  */
    2872             : Param *
    2873         422 : SS_make_initplan_output_param(PlannerInfo *root,
    2874             :                               Oid resulttype, int32 resulttypmod,
    2875             :                               Oid resultcollation)
    2876             : {
    2877         422 :     return generate_new_exec_param(root, resulttype,
    2878             :                                    resulttypmod, resultcollation);
    2879             : }
    2880             : 
    2881             : /*
    2882             :  * SS_make_initplan_from_plan - given a plan tree, make it an InitPlan
    2883             :  *
    2884             :  * We build an EXPR_SUBLINK SubPlan node and put it into the initplan
    2885             :  * list for the outer query level.  A Param that represents the initplan's
    2886             :  * output has already been assigned using SS_make_initplan_output_param.
    2887             :  */
    2888             : void
    2889         360 : SS_make_initplan_from_plan(PlannerInfo *root,
    2890             :                            PlannerInfo *subroot, Plan *plan,
    2891             :                            Param *prm)
    2892             : {
    2893             :     SubPlan    *node;
    2894             : 
    2895             :     /*
    2896             :      * Add the subplan and its PlannerInfo to the global lists.
    2897             :      */
    2898         360 :     root->glob->subplans = lappend(root->glob->subplans, plan);
    2899         360 :     root->glob->subroots = lappend(root->glob->subroots, subroot);
    2900             : 
    2901             :     /*
    2902             :      * Create a SubPlan node and add it to the outer list of InitPlans. Note
    2903             :      * it has to appear after any other InitPlans it might depend on (see
    2904             :      * comments in ExecReScan).
    2905             :      */
    2906         360 :     node = makeNode(SubPlan);
    2907         360 :     node->subLinkType = EXPR_SUBLINK;
    2908         360 :     node->plan_id = list_length(root->glob->subplans);
    2909         360 :     node->plan_name = psprintf("InitPlan %d (returns $%d)",
    2910             :                                node->plan_id, prm->paramid);
    2911         360 :     get_first_col_type(plan, &node->firstColType, &node->firstColTypmod,
    2912             :                        &node->firstColCollation);
    2913         360 :     node->setParam = list_make1_int(prm->paramid);
    2914             : 
    2915         360 :     root->init_plans = lappend(root->init_plans, node);
    2916             : 
    2917             :     /*
    2918             :      * The node can't have any inputs (since it's an initplan), so the
    2919             :      * parParam and args lists remain empty.
    2920             :      */
    2921             : 
    2922             :     /* Set costs of SubPlan using info from the plan tree */
    2923         360 :     cost_subplan(subroot, node, plan);
    2924         360 : }

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