LCOV - code coverage report
Current view: top level - src/backend/optimizer/util - inherit.c (source / functions) Hit Total Coverage
Test: PostgreSQL 17devel Lines: 231 235 98.3 %
Date: 2024-04-25 19:11:21 Functions: 8 8 100.0 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : /*-------------------------------------------------------------------------
       2             :  *
       3             :  * inherit.c
       4             :  *    Routines to process child relations in inheritance trees
       5             :  *
       6             :  * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
       7             :  * Portions Copyright (c) 1994, Regents of the University of California
       8             :  *
       9             :  *
      10             :  * IDENTIFICATION
      11             :  *    src/backend/optimizer/util/inherit.c
      12             :  *
      13             :  *-------------------------------------------------------------------------
      14             :  */
      15             : #include "postgres.h"
      16             : 
      17             : #include "access/sysattr.h"
      18             : #include "access/table.h"
      19             : #include "catalog/partition.h"
      20             : #include "catalog/pg_inherits.h"
      21             : #include "catalog/pg_type.h"
      22             : #include "miscadmin.h"
      23             : #include "nodes/makefuncs.h"
      24             : #include "optimizer/appendinfo.h"
      25             : #include "optimizer/inherit.h"
      26             : #include "optimizer/optimizer.h"
      27             : #include "optimizer/pathnode.h"
      28             : #include "optimizer/plancat.h"
      29             : #include "optimizer/planmain.h"
      30             : #include "optimizer/planner.h"
      31             : #include "optimizer/prep.h"
      32             : #include "optimizer/restrictinfo.h"
      33             : #include "parser/parsetree.h"
      34             : #include "parser/parse_relation.h"
      35             : #include "partitioning/partdesc.h"
      36             : #include "partitioning/partprune.h"
      37             : #include "utils/rel.h"
      38             : 
      39             : 
      40             : static void expand_partitioned_rtentry(PlannerInfo *root, RelOptInfo *relinfo,
      41             :                                        RangeTblEntry *parentrte,
      42             :                                        Index parentRTindex, Relation parentrel,
      43             :                                        Bitmapset *parent_updatedCols,
      44             :                                        PlanRowMark *top_parentrc, LOCKMODE lockmode);
      45             : static void expand_single_inheritance_child(PlannerInfo *root,
      46             :                                             RangeTblEntry *parentrte,
      47             :                                             Index parentRTindex, Relation parentrel,
      48             :                                             PlanRowMark *top_parentrc, Relation childrel,
      49             :                                             RangeTblEntry **childrte_p,
      50             :                                             Index *childRTindex_p);
      51             : static Bitmapset *translate_col_privs(const Bitmapset *parent_privs,
      52             :                                       List *translated_vars);
      53             : static Bitmapset *translate_col_privs_multilevel(PlannerInfo *root,
      54             :                                                  RelOptInfo *rel,
      55             :                                                  RelOptInfo *parent_rel,
      56             :                                                  Bitmapset *parent_cols);
      57             : static void expand_appendrel_subquery(PlannerInfo *root, RelOptInfo *rel,
      58             :                                       RangeTblEntry *rte, Index rti);
      59             : 
      60             : 
      61             : /*
      62             :  * expand_inherited_rtentry
      63             :  *      Expand a rangetable entry that has the "inh" bit set.
      64             :  *
      65             :  * "inh" is only allowed in two cases: RELATION and SUBQUERY RTEs.
      66             :  *
      67             :  * "inh" on a plain RELATION RTE means that it is a partitioned table or the
      68             :  * parent of a traditional-inheritance set.  In this case we must add entries
      69             :  * for all the interesting child tables to the query's rangetable, and build
      70             :  * additional planner data structures for them, including RelOptInfos,
      71             :  * AppendRelInfos, and possibly PlanRowMarks.
      72             :  *
      73             :  * Note that the original RTE is considered to represent the whole inheritance
      74             :  * set.  In the case of traditional inheritance, the first of the generated
      75             :  * RTEs is an RTE for the same table, but with inh = false, to represent the
      76             :  * parent table in its role as a simple member of the inheritance set.  For
      77             :  * partitioning, we don't need a second RTE because the partitioned table
      78             :  * itself has no data and need not be scanned.
      79             :  *
      80             :  * "inh" on a SUBQUERY RTE means that it's the parent of a UNION ALL group,
      81             :  * which is treated as an appendrel similarly to inheritance cases; however,
      82             :  * we already made RTEs and AppendRelInfos for the subqueries.  We only need
      83             :  * to build RelOptInfos for them, which is done by expand_appendrel_subquery.
      84             :  */
      85             : void
      86       17250 : expand_inherited_rtentry(PlannerInfo *root, RelOptInfo *rel,
      87             :                          RangeTblEntry *rte, Index rti)
      88             : {
      89             :     Oid         parentOID;
      90             :     Relation    oldrelation;
      91             :     LOCKMODE    lockmode;
      92             :     PlanRowMark *oldrc;
      93       17250 :     bool        old_isParent = false;
      94       17250 :     int         old_allMarkTypes = 0;
      95             : 
      96             :     Assert(rte->inh);            /* else caller error */
      97             : 
      98       17250 :     if (rte->rtekind == RTE_SUBQUERY)
      99             :     {
     100        1766 :         expand_appendrel_subquery(root, rel, rte, rti);
     101        1766 :         return;
     102             :     }
     103             : 
     104             :     Assert(rte->rtekind == RTE_RELATION);
     105             : 
     106       15484 :     parentOID = rte->relid;
     107             : 
     108             :     /*
     109             :      * We used to check has_subclass() here, but there's no longer any need
     110             :      * to, because subquery_planner already did.
     111             :      */
     112             : 
     113             :     /*
     114             :      * The rewriter should already have obtained an appropriate lock on each
     115             :      * relation named in the query, so we can open the parent relation without
     116             :      * locking it.  However, for each child relation we add to the query, we
     117             :      * must obtain an appropriate lock, because this will be the first use of
     118             :      * those relations in the parse/rewrite/plan pipeline.  Child rels should
     119             :      * use the same lockmode as their parent.
     120             :      */
     121       15484 :     oldrelation = table_open(parentOID, NoLock);
     122       15484 :     lockmode = rte->rellockmode;
     123             : 
     124             :     /*
     125             :      * If parent relation is selected FOR UPDATE/SHARE, we need to mark its
     126             :      * PlanRowMark as isParent = true, and generate a new PlanRowMark for each
     127             :      * child.
     128             :      */
     129       15484 :     oldrc = get_plan_rowmark(root->rowMarks, rti);
     130       15484 :     if (oldrc)
     131             :     {
     132        1508 :         old_isParent = oldrc->isParent;
     133        1508 :         oldrc->isParent = true;
     134             :         /* Save initial value of allMarkTypes before children add to it */
     135        1508 :         old_allMarkTypes = oldrc->allMarkTypes;
     136             :     }
     137             : 
     138             :     /* Scan the inheritance set and expand it */
     139       15484 :     if (oldrelation->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
     140             :     {
     141             :         RTEPermissionInfo *perminfo;
     142             : 
     143       13042 :         perminfo = getRTEPermissionInfo(root->parse->rteperminfos, rte);
     144             : 
     145             :         /*
     146             :          * Partitioned table, so set up for partitioning.
     147             :          */
     148             :         Assert(rte->relkind == RELKIND_PARTITIONED_TABLE);
     149             : 
     150             :         /*
     151             :          * Recursively expand and lock the partitions.  While at it, also
     152             :          * extract the partition key columns of all the partitioned tables.
     153             :          */
     154       13042 :         expand_partitioned_rtentry(root, rel, rte, rti,
     155             :                                    oldrelation,
     156             :                                    perminfo->updatedCols,
     157             :                                    oldrc, lockmode);
     158             :     }
     159             :     else
     160             :     {
     161             :         /*
     162             :          * Ordinary table, so process traditional-inheritance children.  (Note
     163             :          * that partitioned tables are not allowed to have inheritance
     164             :          * children, so it's not possible for both cases to apply.)
     165             :          */
     166             :         List       *inhOIDs;
     167             :         ListCell   *l;
     168             : 
     169             :         /* Scan for all members of inheritance set, acquire needed locks */
     170        2442 :         inhOIDs = find_all_inheritors(parentOID, lockmode, NULL);
     171             : 
     172             :         /*
     173             :          * We used to special-case the situation where the table no longer has
     174             :          * any children, by clearing rte->inh and exiting.  That no longer
     175             :          * works, because this function doesn't get run until after decisions
     176             :          * have been made that depend on rte->inh.  We have to treat such
     177             :          * situations as normal inheritance.  The table itself should always
     178             :          * have been found, though.
     179             :          */
     180             :         Assert(inhOIDs != NIL);
     181             :         Assert(linitial_oid(inhOIDs) == parentOID);
     182             : 
     183             :         /* Expand simple_rel_array and friends to hold child objects. */
     184        2442 :         expand_planner_arrays(root, list_length(inhOIDs));
     185             : 
     186             :         /*
     187             :          * Expand inheritance children in the order the OIDs were returned by
     188             :          * find_all_inheritors.
     189             :          */
     190        9120 :         foreach(l, inhOIDs)
     191             :         {
     192        6680 :             Oid         childOID = lfirst_oid(l);
     193             :             Relation    newrelation;
     194             :             RangeTblEntry *childrte;
     195             :             Index       childRTindex;
     196             : 
     197             :             /* Open rel if needed; we already have required locks */
     198        6680 :             if (childOID != parentOID)
     199        4238 :                 newrelation = table_open(childOID, NoLock);
     200             :             else
     201        2442 :                 newrelation = oldrelation;
     202             : 
     203             :             /*
     204             :              * It is possible that the parent table has children that are temp
     205             :              * tables of other backends.  We cannot safely access such tables
     206             :              * (because of buffering issues), and the best thing to do seems
     207             :              * to be to silently ignore them.
     208             :              */
     209        6680 :             if (childOID != parentOID && RELATION_IS_OTHER_TEMP(newrelation))
     210             :             {
     211          42 :                 table_close(newrelation, lockmode);
     212          42 :                 continue;
     213             :             }
     214             : 
     215             :             /* Create RTE and AppendRelInfo, plus PlanRowMark if needed. */
     216        6638 :             expand_single_inheritance_child(root, rte, rti, oldrelation,
     217             :                                             oldrc, newrelation,
     218             :                                             &childrte, &childRTindex);
     219             : 
     220             :             /* Create the otherrel RelOptInfo too. */
     221        6636 :             (void) build_simple_rel(root, childRTindex, rel);
     222             : 
     223             :             /* Close child relations, but keep locks */
     224        6636 :             if (childOID != parentOID)
     225        4194 :                 table_close(newrelation, NoLock);
     226             :         }
     227             :     }
     228             : 
     229             :     /*
     230             :      * Some children might require different mark types, which would've been
     231             :      * reported into oldrc.  If so, add relevant entries to the top-level
     232             :      * targetlist and update parent rel's reltarget.  This should match what
     233             :      * preprocess_targetlist() would have added if the mark types had been
     234             :      * requested originally.
     235             :      *
     236             :      * (Someday it might be useful to fold these resjunk columns into the
     237             :      * row-identity-column management used for UPDATE/DELETE.  Today is not
     238             :      * that day, however.)
     239             :      */
     240       15482 :     if (oldrc)
     241             :     {
     242        1508 :         int         new_allMarkTypes = oldrc->allMarkTypes;
     243             :         Var        *var;
     244             :         TargetEntry *tle;
     245             :         char        resname[32];
     246        1508 :         List       *newvars = NIL;
     247             : 
     248             :         /* Add TID junk Var if needed, unless we had it already */
     249        1508 :         if (new_allMarkTypes & ~(1 << ROW_MARK_COPY) &&
     250        1504 :             !(old_allMarkTypes & ~(1 << ROW_MARK_COPY)))
     251             :         {
     252             :             /* Need to fetch TID */
     253           4 :             var = makeVar(oldrc->rti,
     254             :                           SelfItemPointerAttributeNumber,
     255             :                           TIDOID,
     256             :                           -1,
     257             :                           InvalidOid,
     258             :                           0);
     259           4 :             snprintf(resname, sizeof(resname), "ctid%u", oldrc->rowmarkId);
     260           4 :             tle = makeTargetEntry((Expr *) var,
     261           4 :                                   list_length(root->processed_tlist) + 1,
     262             :                                   pstrdup(resname),
     263             :                                   true);
     264           4 :             root->processed_tlist = lappend(root->processed_tlist, tle);
     265           4 :             newvars = lappend(newvars, var);
     266             :         }
     267             : 
     268             :         /* Add whole-row junk Var if needed, unless we had it already */
     269        1508 :         if ((new_allMarkTypes & (1 << ROW_MARK_COPY)) &&
     270          46 :             !(old_allMarkTypes & (1 << ROW_MARK_COPY)))
     271             :         {
     272          38 :             var = makeWholeRowVar(planner_rt_fetch(oldrc->rti, root),
     273          38 :                                   oldrc->rti,
     274             :                                   0,
     275             :                                   false);
     276          38 :             snprintf(resname, sizeof(resname), "wholerow%u", oldrc->rowmarkId);
     277          38 :             tle = makeTargetEntry((Expr *) var,
     278          38 :                                   list_length(root->processed_tlist) + 1,
     279             :                                   pstrdup(resname),
     280             :                                   true);
     281          38 :             root->processed_tlist = lappend(root->processed_tlist, tle);
     282          38 :             newvars = lappend(newvars, var);
     283             :         }
     284             : 
     285             :         /* Add tableoid junk Var, unless we had it already */
     286        1508 :         if (!old_isParent)
     287             :         {
     288        1508 :             var = makeVar(oldrc->rti,
     289             :                           TableOidAttributeNumber,
     290             :                           OIDOID,
     291             :                           -1,
     292             :                           InvalidOid,
     293             :                           0);
     294        1508 :             snprintf(resname, sizeof(resname), "tableoid%u", oldrc->rowmarkId);
     295        1508 :             tle = makeTargetEntry((Expr *) var,
     296        1508 :                                   list_length(root->processed_tlist) + 1,
     297             :                                   pstrdup(resname),
     298             :                                   true);
     299        1508 :             root->processed_tlist = lappend(root->processed_tlist, tle);
     300        1508 :             newvars = lappend(newvars, var);
     301             :         }
     302             : 
     303             :         /*
     304             :          * Add the newly added Vars to parent's reltarget.  We needn't worry
     305             :          * about the children's reltargets, they'll be made later.
     306             :          */
     307        1508 :         add_vars_to_targetlist(root, newvars, bms_make_singleton(0));
     308             :     }
     309             : 
     310       15482 :     table_close(oldrelation, NoLock);
     311             : }
     312             : 
     313             : /*
     314             :  * expand_partitioned_rtentry
     315             :  *      Recursively expand an RTE for a partitioned table.
     316             :  */
     317             : static void
     318       16186 : expand_partitioned_rtentry(PlannerInfo *root, RelOptInfo *relinfo,
     319             :                            RangeTblEntry *parentrte,
     320             :                            Index parentRTindex, Relation parentrel,
     321             :                            Bitmapset *parent_updatedCols,
     322             :                            PlanRowMark *top_parentrc, LOCKMODE lockmode)
     323             : {
     324             :     PartitionDesc partdesc;
     325             :     Bitmapset  *live_parts;
     326             :     int         num_live_parts;
     327             :     int         i;
     328             : 
     329       16186 :     check_stack_depth();
     330             : 
     331             :     Assert(parentrte->inh);
     332             : 
     333       16186 :     partdesc = PartitionDirectoryLookup(root->glob->partition_directory,
     334             :                                         parentrel);
     335             : 
     336             :     /* A partitioned table should always have a partition descriptor. */
     337             :     Assert(partdesc);
     338             : 
     339             :     /*
     340             :      * Note down whether any partition key cols are being updated. Though it's
     341             :      * the root partitioned table's updatedCols we are interested in,
     342             :      * parent_updatedCols provided by the caller contains the root partrel's
     343             :      * updatedCols translated to match the attribute ordering of parentrel.
     344             :      */
     345       16186 :     if (!root->partColsUpdated)
     346       15880 :         root->partColsUpdated =
     347       15880 :             has_partition_attrs(parentrel, parent_updatedCols, NULL);
     348             : 
     349             :     /* Nothing further to do here if there are no partitions. */
     350       16186 :     if (partdesc->nparts == 0)
     351          36 :         return;
     352             : 
     353             :     /*
     354             :      * Perform partition pruning using restriction clauses assigned to parent
     355             :      * relation.  live_parts will contain PartitionDesc indexes of partitions
     356             :      * that survive pruning.  Below, we will initialize child objects for the
     357             :      * surviving partitions.
     358             :      */
     359       16150 :     relinfo->live_parts = live_parts = prune_append_rel_partitions(relinfo);
     360             : 
     361             :     /* Expand simple_rel_array and friends to hold child objects. */
     362       16150 :     num_live_parts = bms_num_members(live_parts);
     363       16150 :     if (num_live_parts > 0)
     364       15856 :         expand_planner_arrays(root, num_live_parts);
     365             : 
     366             :     /*
     367             :      * We also store partition RelOptInfo pointers in the parent relation.
     368             :      * Since we're palloc0'ing, slots corresponding to pruned partitions will
     369             :      * contain NULL.
     370             :      */
     371             :     Assert(relinfo->part_rels == NULL);
     372       16150 :     relinfo->part_rels = (RelOptInfo **)
     373       16150 :         palloc0(relinfo->nparts * sizeof(RelOptInfo *));
     374             : 
     375             :     /*
     376             :      * Create a child RTE for each live partition.  Note that unlike
     377             :      * traditional inheritance, we don't need a child RTE for the partitioned
     378             :      * table itself, because it's not going to be scanned.
     379             :      */
     380       16150 :     i = -1;
     381       48196 :     while ((i = bms_next_member(live_parts, i)) >= 0)
     382             :     {
     383       32046 :         Oid         childOID = partdesc->oids[i];
     384             :         Relation    childrel;
     385             :         RangeTblEntry *childrte;
     386             :         Index       childRTindex;
     387             :         RelOptInfo *childrelinfo;
     388             : 
     389             :         /* Open rel, acquiring required locks */
     390       32046 :         childrel = table_open(childOID, lockmode);
     391             : 
     392             :         /*
     393             :          * Temporary partitions belonging to other sessions should have been
     394             :          * disallowed at definition, but for paranoia's sake, let's double
     395             :          * check.
     396             :          */
     397       32046 :         if (RELATION_IS_OTHER_TEMP(childrel))
     398           0 :             elog(ERROR, "temporary relation from another session found as partition");
     399             : 
     400             :         /* Create RTE and AppendRelInfo, plus PlanRowMark if needed. */
     401       32046 :         expand_single_inheritance_child(root, parentrte, parentRTindex,
     402             :                                         parentrel, top_parentrc, childrel,
     403             :                                         &childrte, &childRTindex);
     404             : 
     405             :         /* Create the otherrel RelOptInfo too. */
     406       32046 :         childrelinfo = build_simple_rel(root, childRTindex, relinfo);
     407       32046 :         relinfo->part_rels[i] = childrelinfo;
     408       64092 :         relinfo->all_partrels = bms_add_members(relinfo->all_partrels,
     409       32046 :                                                 childrelinfo->relids);
     410             : 
     411             :         /* If this child is itself partitioned, recurse */
     412       32046 :         if (childrel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
     413             :         {
     414        3144 :             AppendRelInfo *appinfo = root->append_rel_array[childRTindex];
     415             :             Bitmapset  *child_updatedCols;
     416             : 
     417        3144 :             child_updatedCols = translate_col_privs(parent_updatedCols,
     418             :                                                     appinfo->translated_vars);
     419             : 
     420        3144 :             expand_partitioned_rtentry(root, childrelinfo,
     421             :                                        childrte, childRTindex,
     422             :                                        childrel,
     423             :                                        child_updatedCols,
     424             :                                        top_parentrc, lockmode);
     425             :         }
     426             : 
     427             :         /* Close child relation, but keep locks */
     428       32046 :         table_close(childrel, NoLock);
     429             :     }
     430             : }
     431             : 
     432             : /*
     433             :  * expand_single_inheritance_child
     434             :  *      Build a RangeTblEntry and an AppendRelInfo, plus maybe a PlanRowMark.
     435             :  *
     436             :  * We now expand the partition hierarchy level by level, creating a
     437             :  * corresponding hierarchy of AppendRelInfos and RelOptInfos, where each
     438             :  * partitioned descendant acts as a parent of its immediate partitions.
     439             :  * (This is a difference from what older versions of PostgreSQL did and what
     440             :  * is still done in the case of table inheritance for unpartitioned tables,
     441             :  * where the hierarchy is flattened during RTE expansion.)
     442             :  *
     443             :  * PlanRowMarks still carry the top-parent's RTI, and the top-parent's
     444             :  * allMarkTypes field still accumulates values from all descendents.
     445             :  *
     446             :  * "parentrte" and "parentRTindex" are immediate parent's RTE and
     447             :  * RTI. "top_parentrc" is top parent's PlanRowMark.
     448             :  *
     449             :  * The child RangeTblEntry and its RTI are returned in "childrte_p" and
     450             :  * "childRTindex_p" resp.
     451             :  */
     452             : static void
     453       38684 : expand_single_inheritance_child(PlannerInfo *root, RangeTblEntry *parentrte,
     454             :                                 Index parentRTindex, Relation parentrel,
     455             :                                 PlanRowMark *top_parentrc, Relation childrel,
     456             :                                 RangeTblEntry **childrte_p,
     457             :                                 Index *childRTindex_p)
     458             : {
     459       38684 :     Query      *parse = root->parse;
     460       38684 :     Oid         parentOID PG_USED_FOR_ASSERTS_ONLY =
     461             :         RelationGetRelid(parentrel);
     462       38684 :     Oid         childOID = RelationGetRelid(childrel);
     463             :     RangeTblEntry *childrte;
     464             :     Index       childRTindex;
     465             :     AppendRelInfo *appinfo;
     466             :     TupleDesc   child_tupdesc;
     467             :     List       *parent_colnames;
     468             :     List       *child_colnames;
     469             : 
     470             :     /*
     471             :      * Build an RTE for the child, and attach to query's rangetable list. We
     472             :      * copy most scalar fields of the parent's RTE, but replace relation OID,
     473             :      * relkind, and inh for the child.  Set the child's securityQuals to
     474             :      * empty, because we only want to apply the parent's RLS conditions
     475             :      * regardless of what RLS properties individual children may have. (This
     476             :      * is an intentional choice to make inherited RLS work like regular
     477             :      * permissions checks.) The parent securityQuals will be propagated to
     478             :      * children along with other base restriction clauses, so we don't need to
     479             :      * do it here.  Other infrastructure of the parent RTE has to be
     480             :      * translated to match the child table's column ordering, which we do
     481             :      * below, so a "flat" copy is sufficient to start with.
     482             :      */
     483       38684 :     childrte = makeNode(RangeTblEntry);
     484       38684 :     memcpy(childrte, parentrte, sizeof(RangeTblEntry));
     485             :     Assert(parentrte->rtekind == RTE_RELATION); /* else this is dubious */
     486       38684 :     childrte->relid = childOID;
     487       38684 :     childrte->relkind = childrel->rd_rel->relkind;
     488             :     /* A partitioned child will need to be expanded further. */
     489       38684 :     if (childrte->relkind == RELKIND_PARTITIONED_TABLE)
     490             :     {
     491             :         Assert(childOID != parentOID);
     492        3144 :         childrte->inh = true;
     493             :     }
     494             :     else
     495       35540 :         childrte->inh = false;
     496       38684 :     childrte->securityQuals = NIL;
     497             : 
     498             :     /* No permission checking for child RTEs. */
     499       38684 :     childrte->perminfoindex = 0;
     500             : 
     501             :     /* Link not-yet-fully-filled child RTE into data structures */
     502       38684 :     parse->rtable = lappend(parse->rtable, childrte);
     503       38684 :     childRTindex = list_length(parse->rtable);
     504       38684 :     *childrte_p = childrte;
     505       38684 :     *childRTindex_p = childRTindex;
     506             : 
     507             :     /*
     508             :      * Build an AppendRelInfo struct for each parent/child pair.
     509             :      */
     510       38684 :     appinfo = make_append_rel_info(parentrel, childrel,
     511             :                                    parentRTindex, childRTindex);
     512       38682 :     root->append_rel_list = lappend(root->append_rel_list, appinfo);
     513             : 
     514             :     /* tablesample is probably null, but copy it */
     515       38682 :     childrte->tablesample = copyObject(parentrte->tablesample);
     516             : 
     517             :     /*
     518             :      * Construct an alias clause for the child, which we can also use as eref.
     519             :      * This is important so that EXPLAIN will print the right column aliases
     520             :      * for child-table columns.  (Since ruleutils.c doesn't have any easy way
     521             :      * to reassociate parent and child columns, we must get the child column
     522             :      * aliases right to start with.  Note that setting childrte->alias forces
     523             :      * ruleutils.c to use these column names, which it otherwise would not.)
     524             :      */
     525       38682 :     child_tupdesc = RelationGetDescr(childrel);
     526       38682 :     parent_colnames = parentrte->eref->colnames;
     527       38682 :     child_colnames = NIL;
     528      148058 :     for (int cattno = 0; cattno < child_tupdesc->natts; cattno++)
     529             :     {
     530      109376 :         Form_pg_attribute att = TupleDescAttr(child_tupdesc, cattno);
     531             :         const char *attname;
     532             : 
     533      109376 :         if (att->attisdropped)
     534             :         {
     535             :             /* Always insert an empty string for a dropped column */
     536        2234 :             attname = "";
     537             :         }
     538      210414 :         else if (appinfo->parent_colnos[cattno] > 0 &&
     539      103272 :                  appinfo->parent_colnos[cattno] <= list_length(parent_colnames))
     540             :         {
     541             :             /* Duplicate the query-assigned name for the parent column */
     542      103272 :             attname = strVal(list_nth(parent_colnames,
     543             :                                       appinfo->parent_colnos[cattno] - 1));
     544             :         }
     545             :         else
     546             :         {
     547             :             /* New column, just use its real name */
     548        3870 :             attname = NameStr(att->attname);
     549             :         }
     550      109376 :         child_colnames = lappend(child_colnames, makeString(pstrdup(attname)));
     551             :     }
     552             : 
     553             :     /*
     554             :      * We just duplicate the parent's table alias name for each child.  If the
     555             :      * plan gets printed, ruleutils.c has to sort out unique table aliases to
     556             :      * use, which it can handle.
     557             :      */
     558       38682 :     childrte->alias = childrte->eref = makeAlias(parentrte->eref->aliasname,
     559             :                                                  child_colnames);
     560             : 
     561             :     /*
     562             :      * Store the RTE and appinfo in the respective PlannerInfo arrays, which
     563             :      * the caller must already have allocated space for.
     564             :      */
     565             :     Assert(childRTindex < root->simple_rel_array_size);
     566             :     Assert(root->simple_rte_array[childRTindex] == NULL);
     567       38682 :     root->simple_rte_array[childRTindex] = childrte;
     568             :     Assert(root->append_rel_array[childRTindex] == NULL);
     569       38682 :     root->append_rel_array[childRTindex] = appinfo;
     570             : 
     571             :     /*
     572             :      * Build a PlanRowMark if parent is marked FOR UPDATE/SHARE.
     573             :      */
     574       38682 :     if (top_parentrc)
     575             :     {
     576        2128 :         PlanRowMark *childrc = makeNode(PlanRowMark);
     577             : 
     578        2128 :         childrc->rti = childRTindex;
     579        2128 :         childrc->prti = top_parentrc->rti;
     580        2128 :         childrc->rowmarkId = top_parentrc->rowmarkId;
     581             :         /* Reselect rowmark type, because relkind might not match parent */
     582        2128 :         childrc->markType = select_rowmark_type(childrte,
     583             :                                                 top_parentrc->strength);
     584        2128 :         childrc->allMarkTypes = (1 << childrc->markType);
     585        2128 :         childrc->strength = top_parentrc->strength;
     586        2128 :         childrc->waitPolicy = top_parentrc->waitPolicy;
     587             : 
     588             :         /*
     589             :          * We mark RowMarks for partitioned child tables as parent RowMarks so
     590             :          * that the executor ignores them (except their existence means that
     591             :          * the child tables will be locked using the appropriate mode).
     592             :          */
     593        2128 :         childrc->isParent = (childrte->relkind == RELKIND_PARTITIONED_TABLE);
     594             : 
     595             :         /* Include child's rowmark type in top parent's allMarkTypes */
     596        2128 :         top_parentrc->allMarkTypes |= childrc->allMarkTypes;
     597             : 
     598        2128 :         root->rowMarks = lappend(root->rowMarks, childrc);
     599             :     }
     600             : 
     601             :     /*
     602             :      * If we are creating a child of the query target relation (only possible
     603             :      * in UPDATE/DELETE/MERGE), add it to all_result_relids, as well as
     604             :      * leaf_result_relids if appropriate, and make sure that we generate
     605             :      * required row-identity data.
     606             :      */
     607       38682 :     if (bms_is_member(parentRTindex, root->all_result_relids))
     608             :     {
     609             :         /* OK, record the child as a result rel too. */
     610        5424 :         root->all_result_relids = bms_add_member(root->all_result_relids,
     611             :                                                  childRTindex);
     612             : 
     613             :         /* Non-leaf partitions don't need any row identity info. */
     614        5424 :         if (childrte->relkind != RELKIND_PARTITIONED_TABLE)
     615             :         {
     616             :             Var        *rrvar;
     617             : 
     618        4878 :             root->leaf_result_relids = bms_add_member(root->leaf_result_relids,
     619             :                                                       childRTindex);
     620             : 
     621             :             /*
     622             :              * If we have any child target relations, assume they all need to
     623             :              * generate a junk "tableoid" column.  (If only one child survives
     624             :              * pruning, we wouldn't really need this, but it's not worth
     625             :              * thrashing about to avoid it.)
     626             :              */
     627        4878 :             rrvar = makeVar(childRTindex,
     628             :                             TableOidAttributeNumber,
     629             :                             OIDOID,
     630             :                             -1,
     631             :                             InvalidOid,
     632             :                             0);
     633        4878 :             add_row_identity_var(root, rrvar, childRTindex, "tableoid");
     634             : 
     635             :             /* Register any row-identity columns needed by this child. */
     636        4878 :             add_row_identity_columns(root, childRTindex,
     637             :                                      childrte, childrel);
     638             :         }
     639             :     }
     640       38682 : }
     641             : 
     642             : /*
     643             :  * get_rel_all_updated_cols
     644             :  *      Returns the set of columns of a given "simple" relation that are
     645             :  *      updated by this query.
     646             :  */
     647             : Bitmapset *
     648          70 : get_rel_all_updated_cols(PlannerInfo *root, RelOptInfo *rel)
     649             : {
     650             :     Index       relid;
     651             :     RangeTblEntry *rte;
     652             :     RTEPermissionInfo *perminfo;
     653             :     Bitmapset  *updatedCols,
     654             :                *extraUpdatedCols;
     655             : 
     656             :     Assert(root->parse->commandType == CMD_UPDATE);
     657             :     Assert(IS_SIMPLE_REL(rel));
     658             : 
     659             :     /*
     660             :      * We obtain updatedCols for the query's result relation.  Then, if
     661             :      * necessary, we map it to the column numbers of the relation for which
     662             :      * they were requested.
     663             :      */
     664          70 :     relid = root->parse->resultRelation;
     665          70 :     rte = planner_rt_fetch(relid, root);
     666          70 :     perminfo = getRTEPermissionInfo(root->parse->rteperminfos, rte);
     667             : 
     668          70 :     updatedCols = perminfo->updatedCols;
     669             : 
     670          70 :     if (rel->relid != relid)
     671             :     {
     672          34 :         RelOptInfo *top_parent_rel = find_base_rel(root, relid);
     673             : 
     674             :         Assert(IS_OTHER_REL(rel));
     675             : 
     676          34 :         updatedCols = translate_col_privs_multilevel(root, rel, top_parent_rel,
     677             :                                                      updatedCols);
     678             :     }
     679             : 
     680             :     /*
     681             :      * Now we must check to see if there are any generated columns that depend
     682             :      * on the updatedCols, and add them to the result.
     683             :      */
     684          70 :     extraUpdatedCols = get_dependent_generated_columns(root, rel->relid,
     685             :                                                        updatedCols);
     686             : 
     687          70 :     return bms_union(updatedCols, extraUpdatedCols);
     688             : }
     689             : 
     690             : /*
     691             :  * translate_col_privs
     692             :  *    Translate a bitmapset representing per-column privileges from the
     693             :  *    parent rel's attribute numbering to the child's.
     694             :  *
     695             :  * The only surprise here is that we don't translate a parent whole-row
     696             :  * reference into a child whole-row reference.  That would mean requiring
     697             :  * permissions on all child columns, which is overly strict, since the
     698             :  * query is really only going to reference the inherited columns.  Instead
     699             :  * we set the per-column bits for all inherited columns.
     700             :  */
     701             : static Bitmapset *
     702        3182 : translate_col_privs(const Bitmapset *parent_privs,
     703             :                     List *translated_vars)
     704             : {
     705        3182 :     Bitmapset  *child_privs = NULL;
     706             :     bool        whole_row;
     707             :     int         attno;
     708             :     ListCell   *lc;
     709             : 
     710             :     /* System attributes have the same numbers in all tables */
     711       22274 :     for (attno = FirstLowInvalidHeapAttributeNumber + 1; attno < 0; attno++)
     712             :     {
     713       19092 :         if (bms_is_member(attno - FirstLowInvalidHeapAttributeNumber,
     714             :                           parent_privs))
     715           0 :             child_privs = bms_add_member(child_privs,
     716             :                                          attno - FirstLowInvalidHeapAttributeNumber);
     717             :     }
     718             : 
     719             :     /* Check if parent has whole-row reference */
     720        3182 :     whole_row = bms_is_member(InvalidAttrNumber - FirstLowInvalidHeapAttributeNumber,
     721             :                               parent_privs);
     722             : 
     723             :     /* And now translate the regular user attributes, using the vars list */
     724        3182 :     attno = InvalidAttrNumber;
     725       11538 :     foreach(lc, translated_vars)
     726             :     {
     727        8356 :         Var        *var = lfirst_node(Var, lc);
     728             : 
     729        8356 :         attno++;
     730        8356 :         if (var == NULL)        /* ignore dropped columns */
     731         126 :             continue;
     732       16460 :         if (whole_row ||
     733        8230 :             bms_is_member(attno - FirstLowInvalidHeapAttributeNumber,
     734             :                           parent_privs))
     735         540 :             child_privs = bms_add_member(child_privs,
     736         540 :                                          var->varattno - FirstLowInvalidHeapAttributeNumber);
     737             :     }
     738             : 
     739        3182 :     return child_privs;
     740             : }
     741             : 
     742             : /*
     743             :  * translate_col_privs_multilevel
     744             :  *      Recursively translates the column numbers contained in 'parent_cols'
     745             :  *      to the column numbers of a descendant relation given by 'rel'
     746             :  *
     747             :  * Note that because this is based on translate_col_privs, it will expand
     748             :  * a whole-row reference into all inherited columns.  This is not an issue
     749             :  * for current usages, but beware.
     750             :  */
     751             : static Bitmapset *
     752          38 : translate_col_privs_multilevel(PlannerInfo *root, RelOptInfo *rel,
     753             :                                RelOptInfo *parent_rel,
     754             :                                Bitmapset *parent_cols)
     755             : {
     756             :     AppendRelInfo *appinfo;
     757             : 
     758             :     /* Fast path for easy case. */
     759          38 :     if (parent_cols == NULL)
     760           0 :         return NULL;
     761             : 
     762             :     /* Recurse if immediate parent is not the top parent. */
     763          38 :     if (rel->parent != parent_rel)
     764             :     {
     765           4 :         if (rel->parent)
     766           4 :             parent_cols = translate_col_privs_multilevel(root, rel->parent,
     767             :                                                          parent_rel,
     768             :                                                          parent_cols);
     769             :         else
     770           0 :             elog(ERROR, "rel with relid %u is not a child rel", rel->relid);
     771             :     }
     772             : 
     773             :     /* Now translate for this child. */
     774             :     Assert(root->append_rel_array != NULL);
     775          38 :     appinfo = root->append_rel_array[rel->relid];
     776             :     Assert(appinfo != NULL);
     777             : 
     778          38 :     return translate_col_privs(parent_cols, appinfo->translated_vars);
     779             : }
     780             : 
     781             : /*
     782             :  * expand_appendrel_subquery
     783             :  *      Add "other rel" RelOptInfos for the children of an appendrel baserel
     784             :  *
     785             :  * "rel" is a subquery relation that has the rte->inh flag set, meaning it
     786             :  * is a UNION ALL subquery that's been flattened into an appendrel, with
     787             :  * child subqueries listed in root->append_rel_list.  We need to build
     788             :  * a RelOptInfo for each child relation so that we can plan scans on them.
     789             :  */
     790             : static void
     791        1766 : expand_appendrel_subquery(PlannerInfo *root, RelOptInfo *rel,
     792             :                           RangeTblEntry *rte, Index rti)
     793             : {
     794             :     ListCell   *l;
     795             : 
     796        7060 :     foreach(l, root->append_rel_list)
     797             :     {
     798        5294 :         AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(l);
     799        5294 :         Index       childRTindex = appinfo->child_relid;
     800             :         RangeTblEntry *childrte;
     801             :         RelOptInfo *childrel;
     802             : 
     803             :         /* append_rel_list contains all append rels; ignore others */
     804        5294 :         if (appinfo->parent_relid != rti)
     805        1146 :             continue;
     806             : 
     807             :         /* find the child RTE, which should already exist */
     808             :         Assert(childRTindex < root->simple_rel_array_size);
     809        4148 :         childrte = root->simple_rte_array[childRTindex];
     810             :         Assert(childrte != NULL);
     811             : 
     812             :         /* Build the child RelOptInfo. */
     813        4148 :         childrel = build_simple_rel(root, childRTindex, rel);
     814             : 
     815             :         /* Child may itself be an inherited rel, either table or subquery. */
     816        4148 :         if (childrte->inh)
     817         212 :             expand_inherited_rtentry(root, childrel, childrte, childRTindex);
     818             :     }
     819        1766 : }
     820             : 
     821             : 
     822             : /*
     823             :  * apply_child_basequals
     824             :  *      Populate childrel's base restriction quals from parent rel's quals,
     825             :  *      translating Vars using appinfo and re-checking for quals which are
     826             :  *      constant-TRUE or constant-FALSE when applied to this child relation.
     827             :  *
     828             :  * If any of the resulting clauses evaluate to constant false or NULL, we
     829             :  * return false and don't apply any quals.  Caller should mark the relation as
     830             :  * a dummy rel in this case, since it doesn't need to be scanned.  Constant
     831             :  * true quals are ignored.
     832             :  */
     833             : bool
     834       42830 : apply_child_basequals(PlannerInfo *root, RelOptInfo *parentrel,
     835             :                       RelOptInfo *childrel, RangeTblEntry *childRTE,
     836             :                       AppendRelInfo *appinfo)
     837             : {
     838             :     List       *childquals;
     839             :     Index       cq_min_security;
     840             :     ListCell   *lc;
     841             : 
     842             :     /*
     843             :      * The child rel's targetlist might contain non-Var expressions, which
     844             :      * means that substitution into the quals could produce opportunities for
     845             :      * const-simplification, and perhaps even pseudoconstant quals. Therefore,
     846             :      * transform each RestrictInfo separately to see if it reduces to a
     847             :      * constant or pseudoconstant.  (We must process them separately to keep
     848             :      * track of the security level of each qual.)
     849             :      */
     850       42830 :     childquals = NIL;
     851       42830 :     cq_min_security = UINT_MAX;
     852       70318 :     foreach(lc, parentrel->baserestrictinfo)
     853             :     {
     854       27578 :         RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
     855             :         Node       *childqual;
     856             :         ListCell   *lc2;
     857             : 
     858             :         Assert(IsA(rinfo, RestrictInfo));
     859       27578 :         childqual = adjust_appendrel_attrs(root,
     860       27578 :                                            (Node *) rinfo->clause,
     861             :                                            1, &appinfo);
     862       27578 :         childqual = eval_const_expressions(root, childqual);
     863             :         /* check for flat-out constant */
     864       27578 :         if (childqual && IsA(childqual, Const))
     865             :         {
     866         156 :             if (((Const *) childqual)->constisnull ||
     867         156 :                 !DatumGetBool(((Const *) childqual)->constvalue))
     868             :             {
     869             :                 /* Restriction reduces to constant FALSE or NULL */
     870          90 :                 return false;
     871             :             }
     872             :             /* Restriction reduces to constant TRUE, so drop it */
     873          78 :             continue;
     874             :         }
     875             :         /* might have gotten an AND clause, if so flatten it */
     876       54844 :         foreach(lc2, make_ands_implicit((Expr *) childqual))
     877             :         {
     878       27434 :             Node       *onecq = (Node *) lfirst(lc2);
     879             :             bool        pseudoconstant;
     880             :             RestrictInfo *childrinfo;
     881             : 
     882             :             /* check for pseudoconstant (no Vars or volatile functions) */
     883       27434 :             pseudoconstant =
     884       27480 :                 !contain_vars_of_level(onecq, 0) &&
     885          46 :                 !contain_volatile_functions(onecq);
     886       27434 :             if (pseudoconstant)
     887             :             {
     888             :                 /* tell createplan.c to check for gating quals */
     889          46 :                 root->hasPseudoConstantQuals = true;
     890             :             }
     891             :             /* reconstitute RestrictInfo with appropriate properties */
     892       27434 :             childrinfo = make_restrictinfo(root,
     893             :                                            (Expr *) onecq,
     894       27434 :                                            rinfo->is_pushed_down,
     895       27434 :                                            rinfo->has_clone,
     896       27434 :                                            rinfo->is_clone,
     897             :                                            pseudoconstant,
     898             :                                            rinfo->security_level,
     899             :                                            NULL, NULL, NULL);
     900             : 
     901             :             /* Restriction is proven always false */
     902       27434 :             if (restriction_is_always_false(root, childrinfo))
     903          12 :                 return false;
     904             :             /* Restriction is proven always true, so drop it */
     905       27422 :             if (restriction_is_always_true(root, childrinfo))
     906          12 :                 continue;
     907             : 
     908       27410 :             childquals = lappend(childquals, childrinfo);
     909             :             /* track minimum security level among child quals */
     910       27410 :             cq_min_security = Min(cq_min_security, rinfo->security_level);
     911             :         }
     912             :     }
     913             : 
     914             :     /*
     915             :      * In addition to the quals inherited from the parent, we might have
     916             :      * securityQuals associated with this particular child node.  (Currently
     917             :      * this can only happen in appendrels originating from UNION ALL;
     918             :      * inheritance child tables don't have their own securityQuals, see
     919             :      * expand_single_inheritance_child().)  Pull any such securityQuals up
     920             :      * into the baserestrictinfo for the child.  This is similar to
     921             :      * process_security_barrier_quals() for the parent rel, except that we
     922             :      * can't make any general deductions from such quals, since they don't
     923             :      * hold for the whole appendrel.
     924             :      */
     925       42740 :     if (childRTE->securityQuals)
     926             :     {
     927          12 :         Index       security_level = 0;
     928             : 
     929          24 :         foreach(lc, childRTE->securityQuals)
     930             :         {
     931          12 :             List       *qualset = (List *) lfirst(lc);
     932             :             ListCell   *lc2;
     933             : 
     934          24 :             foreach(lc2, qualset)
     935             :             {
     936          12 :                 Expr       *qual = (Expr *) lfirst(lc2);
     937             : 
     938             :                 /* not likely that we'd see constants here, so no check */
     939          12 :                 childquals = lappend(childquals,
     940          12 :                                      make_restrictinfo(root, qual,
     941             :                                                        true,
     942             :                                                        false, false,
     943             :                                                        false,
     944             :                                                        security_level,
     945             :                                                        NULL, NULL, NULL));
     946          12 :                 cq_min_security = Min(cq_min_security, security_level);
     947             :             }
     948          12 :             security_level++;
     949             :         }
     950             :         Assert(security_level <= root->qual_security_level);
     951             :     }
     952             : 
     953             :     /*
     954             :      * OK, we've got all the baserestrictinfo quals for this child.
     955             :      */
     956       42740 :     childrel->baserestrictinfo = childquals;
     957       42740 :     childrel->baserestrict_min_security = cq_min_security;
     958             : 
     959       42740 :     return true;
     960             : }

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