LCOV - code coverage report
Current view: top level - src/backend/executor - nodeSubplan.c (source / functions) Hit Total Coverage
Test: PostgreSQL 17devel Lines: 402 432 93.1 %
Date: 2024-04-18 05:10:52 Functions: 12 12 100.0 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : /*-------------------------------------------------------------------------
       2             :  *
       3             :  * nodeSubplan.c
       4             :  *    routines to support sub-selects appearing in expressions
       5             :  *
       6             :  * This module is concerned with executing SubPlan expression nodes, which
       7             :  * should not be confused with sub-SELECTs appearing in FROM.  SubPlans are
       8             :  * divided into "initplans", which are those that need only one evaluation per
       9             :  * query (among other restrictions, this requires that they don't use any
      10             :  * direct correlation variables from the parent plan level), and "regular"
      11             :  * subplans, which are re-evaluated every time their result is required.
      12             :  *
      13             :  *
      14             :  * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
      15             :  * Portions Copyright (c) 1994, Regents of the University of California
      16             :  *
      17             :  * IDENTIFICATION
      18             :  *    src/backend/executor/nodeSubplan.c
      19             :  *
      20             :  *-------------------------------------------------------------------------
      21             :  */
      22             : /*
      23             :  *   INTERFACE ROUTINES
      24             :  *      ExecSubPlan  - process a subselect
      25             :  *      ExecInitSubPlan - initialize a subselect
      26             :  */
      27             : #include "postgres.h"
      28             : 
      29             : #include <math.h>
      30             : 
      31             : #include "access/htup_details.h"
      32             : #include "executor/executor.h"
      33             : #include "executor/nodeSubplan.h"
      34             : #include "miscadmin.h"
      35             : #include "nodes/makefuncs.h"
      36             : #include "nodes/nodeFuncs.h"
      37             : #include "optimizer/optimizer.h"
      38             : #include "utils/array.h"
      39             : #include "utils/lsyscache.h"
      40             : #include "utils/memutils.h"
      41             : 
      42             : static Datum ExecHashSubPlan(SubPlanState *node,
      43             :                              ExprContext *econtext,
      44             :                              bool *isNull);
      45             : static Datum ExecScanSubPlan(SubPlanState *node,
      46             :                              ExprContext *econtext,
      47             :                              bool *isNull);
      48             : static void buildSubPlanHash(SubPlanState *node, ExprContext *econtext);
      49             : static bool findPartialMatch(TupleHashTable hashtable, TupleTableSlot *slot,
      50             :                              FmgrInfo *eqfunctions);
      51             : static bool slotAllNulls(TupleTableSlot *slot);
      52             : static bool slotNoNulls(TupleTableSlot *slot);
      53             : 
      54             : 
      55             : /* ----------------------------------------------------------------
      56             :  *      ExecSubPlan
      57             :  *
      58             :  * This is the main entry point for execution of a regular SubPlan.
      59             :  * ----------------------------------------------------------------
      60             :  */
      61             : Datum
      62     2783870 : ExecSubPlan(SubPlanState *node,
      63             :             ExprContext *econtext,
      64             :             bool *isNull)
      65             : {
      66     2783870 :     SubPlan    *subplan = node->subplan;
      67     2783870 :     EState     *estate = node->planstate->state;
      68     2783870 :     ScanDirection dir = estate->es_direction;
      69             :     Datum       retval;
      70             : 
      71     2783870 :     CHECK_FOR_INTERRUPTS();
      72             : 
      73             :     /* Set non-null as default */
      74     2783870 :     *isNull = false;
      75             : 
      76             :     /* Sanity checks */
      77     2783870 :     if (subplan->subLinkType == CTE_SUBLINK)
      78           0 :         elog(ERROR, "CTE subplans should not be executed via ExecSubPlan");
      79     2783870 :     if (subplan->setParam != NIL && subplan->subLinkType != MULTIEXPR_SUBLINK)
      80           0 :         elog(ERROR, "cannot set parent params from subquery");
      81             : 
      82             :     /* Force forward-scan mode for evaluation */
      83     2783870 :     estate->es_direction = ForwardScanDirection;
      84             : 
      85             :     /* Select appropriate evaluation strategy */
      86     2783870 :     if (subplan->useHashTable)
      87     1476276 :         retval = ExecHashSubPlan(node, econtext, isNull);
      88             :     else
      89     1307594 :         retval = ExecScanSubPlan(node, econtext, isNull);
      90             : 
      91             :     /* restore scan direction */
      92     2783864 :     estate->es_direction = dir;
      93             : 
      94     2783864 :     return retval;
      95             : }
      96             : 
      97             : /*
      98             :  * ExecHashSubPlan: store subselect result in an in-memory hash table
      99             :  */
     100             : static Datum
     101     1476276 : ExecHashSubPlan(SubPlanState *node,
     102             :                 ExprContext *econtext,
     103             :                 bool *isNull)
     104             : {
     105     1476276 :     SubPlan    *subplan = node->subplan;
     106     1476276 :     PlanState  *planstate = node->planstate;
     107             :     TupleTableSlot *slot;
     108             : 
     109             :     /* Shouldn't have any direct correlation Vars */
     110     1476276 :     if (subplan->parParam != NIL || node->args != NIL)
     111           0 :         elog(ERROR, "hashed subplan with direct correlation not supported");
     112             : 
     113             :     /*
     114             :      * If first time through or we need to rescan the subplan, build the hash
     115             :      * table.
     116             :      */
     117     1476276 :     if (node->hashtable == NULL || planstate->chgParam != NULL)
     118        1372 :         buildSubPlanHash(node, econtext);
     119             : 
     120             :     /*
     121             :      * The result for an empty subplan is always FALSE; no need to evaluate
     122             :      * lefthand side.
     123             :      */
     124     1476270 :     *isNull = false;
     125     1476270 :     if (!node->havehashrows && !node->havenullrows)
     126      651744 :         return BoolGetDatum(false);
     127             : 
     128             :     /*
     129             :      * Evaluate lefthand expressions and form a projection tuple. First we
     130             :      * have to set the econtext to use (hack alert!).
     131             :      */
     132      824526 :     node->projLeft->pi_exprContext = econtext;
     133      824526 :     slot = ExecProject(node->projLeft);
     134             : 
     135             :     /*
     136             :      * Note: because we are typically called in a per-tuple context, we have
     137             :      * to explicitly clear the projected tuple before returning. Otherwise,
     138             :      * we'll have a double-free situation: the per-tuple context will probably
     139             :      * be reset before we're called again, and then the tuple slot will think
     140             :      * it still needs to free the tuple.
     141             :      */
     142             : 
     143             :     /*
     144             :      * If the LHS is all non-null, probe for an exact match in the main hash
     145             :      * table.  If we find one, the result is TRUE. Otherwise, scan the
     146             :      * partly-null table to see if there are any rows that aren't provably
     147             :      * unequal to the LHS; if so, the result is UNKNOWN.  (We skip that part
     148             :      * if we don't care about UNKNOWN.) Otherwise, the result is FALSE.
     149             :      *
     150             :      * Note: the reason we can avoid a full scan of the main hash table is
     151             :      * that the combining operators are assumed never to yield NULL when both
     152             :      * inputs are non-null.  If they were to do so, we might need to produce
     153             :      * UNKNOWN instead of FALSE because of an UNKNOWN result in comparing the
     154             :      * LHS to some main-table entry --- which is a comparison we will not even
     155             :      * make, unless there's a chance match of hash keys.
     156             :      */
     157      824526 :     if (slotNoNulls(slot))
     158             :     {
     159     1648956 :         if (node->havehashrows &&
     160      824466 :             FindTupleHashEntry(node->hashtable,
     161             :                                slot,
     162             :                                node->cur_eq_comp,
     163             :                                node->lhs_hash_funcs) != NULL)
     164             :         {
     165       63104 :             ExecClearTuple(slot);
     166       63104 :             return BoolGetDatum(true);
     167             :         }
     168      761422 :         if (node->havenullrows &&
     169          36 :             findPartialMatch(node->hashnulls, slot, node->cur_eq_funcs))
     170             :         {
     171          18 :             ExecClearTuple(slot);
     172          18 :             *isNull = true;
     173          18 :             return BoolGetDatum(false);
     174             :         }
     175      761368 :         ExecClearTuple(slot);
     176      761368 :         return BoolGetDatum(false);
     177             :     }
     178             : 
     179             :     /*
     180             :      * When the LHS is partly or wholly NULL, we can never return TRUE. If we
     181             :      * don't care about UNKNOWN, just return FALSE.  Otherwise, if the LHS is
     182             :      * wholly NULL, immediately return UNKNOWN.  (Since the combining
     183             :      * operators are strict, the result could only be FALSE if the sub-select
     184             :      * were empty, but we already handled that case.) Otherwise, we must scan
     185             :      * both the main and partly-null tables to see if there are any rows that
     186             :      * aren't provably unequal to the LHS; if so, the result is UNKNOWN.
     187             :      * Otherwise, the result is FALSE.
     188             :      */
     189          36 :     if (node->hashnulls == NULL)
     190             :     {
     191           0 :         ExecClearTuple(slot);
     192           0 :         return BoolGetDatum(false);
     193             :     }
     194          36 :     if (slotAllNulls(slot))
     195             :     {
     196           0 :         ExecClearTuple(slot);
     197           0 :         *isNull = true;
     198           0 :         return BoolGetDatum(false);
     199             :     }
     200             :     /* Scan partly-null table first, since more likely to get a match */
     201          72 :     if (node->havenullrows &&
     202          36 :         findPartialMatch(node->hashnulls, slot, node->cur_eq_funcs))
     203             :     {
     204          18 :         ExecClearTuple(slot);
     205          18 :         *isNull = true;
     206          18 :         return BoolGetDatum(false);
     207             :     }
     208          24 :     if (node->havehashrows &&
     209           6 :         findPartialMatch(node->hashtable, slot, node->cur_eq_funcs))
     210             :     {
     211           0 :         ExecClearTuple(slot);
     212           0 :         *isNull = true;
     213           0 :         return BoolGetDatum(false);
     214             :     }
     215          18 :     ExecClearTuple(slot);
     216          18 :     return BoolGetDatum(false);
     217             : }
     218             : 
     219             : /*
     220             :  * ExecScanSubPlan: default case where we have to rescan subplan each time
     221             :  */
     222             : static Datum
     223     1307594 : ExecScanSubPlan(SubPlanState *node,
     224             :                 ExprContext *econtext,
     225             :                 bool *isNull)
     226             : {
     227     1307594 :     SubPlan    *subplan = node->subplan;
     228     1307594 :     PlanState  *planstate = node->planstate;
     229     1307594 :     SubLinkType subLinkType = subplan->subLinkType;
     230             :     MemoryContext oldcontext;
     231             :     TupleTableSlot *slot;
     232             :     Datum       result;
     233     1307594 :     bool        found = false;  /* true if got at least one subplan tuple */
     234             :     ListCell   *pvar;
     235             :     ListCell   *l;
     236     1307594 :     ArrayBuildStateAny *astate = NULL;
     237             : 
     238             :     /* Initialize ArrayBuildStateAny in caller's context, if needed */
     239     1307594 :     if (subLinkType == ARRAY_SUBLINK)
     240       44514 :         astate = initArrayResultAny(subplan->firstColType,
     241             :                                     CurrentMemoryContext, true);
     242             : 
     243             :     /*
     244             :      * We are probably in a short-lived expression-evaluation context. Switch
     245             :      * to the per-query context for manipulating the child plan's chgParam,
     246             :      * calling ExecProcNode on it, etc.
     247             :      */
     248     1307594 :     oldcontext = MemoryContextSwitchTo(econtext->ecxt_per_query_memory);
     249             : 
     250             :     /*
     251             :      * Set Params of this plan from parent plan correlation values. (Any
     252             :      * calculation we have to do is done in the parent econtext, since the
     253             :      * Param values don't need to have per-query lifetime.)
     254             :      */
     255             :     Assert(list_length(subplan->parParam) == list_length(node->args));
     256             : 
     257     2640670 :     forboth(l, subplan->parParam, pvar, node->args)
     258             :     {
     259     1333076 :         int         paramid = lfirst_int(l);
     260     1333076 :         ParamExecData *prm = &(econtext->ecxt_param_exec_vals[paramid]);
     261             : 
     262     1333076 :         prm->value = ExecEvalExprSwitchContext((ExprState *) lfirst(pvar),
     263             :                                                econtext,
     264             :                                                &(prm->isnull));
     265     1333076 :         planstate->chgParam = bms_add_member(planstate->chgParam, paramid);
     266             :     }
     267             : 
     268             :     /*
     269             :      * Now that we've set up its parameters, we can reset the subplan.
     270             :      */
     271     1307594 :     ExecReScan(planstate);
     272             : 
     273             :     /*
     274             :      * For all sublink types except EXPR_SUBLINK and ARRAY_SUBLINK, the result
     275             :      * is boolean as are the results of the combining operators. We combine
     276             :      * results across tuples (if the subplan produces more than one) using OR
     277             :      * semantics for ANY_SUBLINK or AND semantics for ALL_SUBLINK.
     278             :      * (ROWCOMPARE_SUBLINK doesn't allow multiple tuples from the subplan.)
     279             :      * NULL results from the combining operators are handled according to the
     280             :      * usual SQL semantics for OR and AND.  The result for no input tuples is
     281             :      * FALSE for ANY_SUBLINK, TRUE for ALL_SUBLINK, NULL for
     282             :      * ROWCOMPARE_SUBLINK.
     283             :      *
     284             :      * For EXPR_SUBLINK we require the subplan to produce no more than one
     285             :      * tuple, else an error is raised.  If zero tuples are produced, we return
     286             :      * NULL.  Assuming we get a tuple, we just use its first column (there can
     287             :      * be only one non-junk column in this case).
     288             :      *
     289             :      * For MULTIEXPR_SUBLINK, we push the per-column subplan outputs out to
     290             :      * the setParams and then return a dummy false value.  There must not be
     291             :      * multiple tuples returned from the subplan; if zero tuples are produced,
     292             :      * set the setParams to NULL.
     293             :      *
     294             :      * For ARRAY_SUBLINK we allow the subplan to produce any number of tuples,
     295             :      * and form an array of the first column's values.  Note in particular
     296             :      * that we produce a zero-element array if no tuples are produced (this is
     297             :      * a change from pre-8.3 behavior of returning NULL).
     298             :      */
     299     1307594 :     result = BoolGetDatum(subLinkType == ALL_SUBLINK);
     300     1307594 :     *isNull = false;
     301             : 
     302     1604898 :     for (slot = ExecProcNode(planstate);
     303     1551100 :          !TupIsNull(slot);
     304      297304 :          slot = ExecProcNode(planstate))
     305             :     {
     306      298118 :         TupleDesc   tdesc = slot->tts_tupleDescriptor;
     307             :         Datum       rowresult;
     308             :         bool        rownull;
     309             :         int         col;
     310             :         ListCell   *plst;
     311             : 
     312      298118 :         if (subLinkType == EXISTS_SUBLINK)
     313             :         {
     314         682 :             found = true;
     315         682 :             result = BoolGetDatum(true);
     316         814 :             break;
     317             :         }
     318             : 
     319      297436 :         if (subLinkType == EXPR_SUBLINK)
     320             :         {
     321             :             /* cannot allow multiple input tuples for EXPR sublink */
     322      281446 :             if (found)
     323           0 :                 ereport(ERROR,
     324             :                         (errcode(ERRCODE_CARDINALITY_VIOLATION),
     325             :                          errmsg("more than one row returned by a subquery used as an expression")));
     326      281446 :             found = true;
     327             : 
     328             :             /*
     329             :              * We need to copy the subplan's tuple in case the result is of
     330             :              * pass-by-ref type --- our return value will point into this
     331             :              * copied tuple!  Can't use the subplan's instance of the tuple
     332             :              * since it won't still be valid after next ExecProcNode() call.
     333             :              * node->curTuple keeps track of the copied tuple for eventual
     334             :              * freeing.
     335             :              */
     336      281446 :             if (node->curTuple)
     337      277582 :                 heap_freetuple(node->curTuple);
     338      281446 :             node->curTuple = ExecCopySlotHeapTuple(slot);
     339             : 
     340      281446 :             result = heap_getattr(node->curTuple, 1, tdesc, isNull);
     341             :             /* keep scanning subplan to make sure there's only one tuple */
     342      286360 :             continue;
     343             :         }
     344             : 
     345       15990 :         if (subLinkType == MULTIEXPR_SUBLINK)
     346             :         {
     347             :             /* cannot allow multiple input tuples for MULTIEXPR sublink */
     348         240 :             if (found)
     349           0 :                 ereport(ERROR,
     350             :                         (errcode(ERRCODE_CARDINALITY_VIOLATION),
     351             :                          errmsg("more than one row returned by a subquery used as an expression")));
     352         240 :             found = true;
     353             : 
     354             :             /*
     355             :              * We need to copy the subplan's tuple in case any result is of
     356             :              * pass-by-ref type --- our output values will point into this
     357             :              * copied tuple!  Can't use the subplan's instance of the tuple
     358             :              * since it won't still be valid after next ExecProcNode() call.
     359             :              * node->curTuple keeps track of the copied tuple for eventual
     360             :              * freeing.
     361             :              */
     362         240 :             if (node->curTuple)
     363         152 :                 heap_freetuple(node->curTuple);
     364         240 :             node->curTuple = ExecCopySlotHeapTuple(slot);
     365             : 
     366             :             /*
     367             :              * Now set all the setParam params from the columns of the tuple
     368             :              */
     369         240 :             col = 1;
     370         714 :             foreach(plst, subplan->setParam)
     371             :             {
     372         474 :                 int         paramid = lfirst_int(plst);
     373             :                 ParamExecData *prmdata;
     374             : 
     375         474 :                 prmdata = &(econtext->ecxt_param_exec_vals[paramid]);
     376             :                 Assert(prmdata->execPlan == NULL);
     377         474 :                 prmdata->value = heap_getattr(node->curTuple, col, tdesc,
     378             :                                               &(prmdata->isnull));
     379         474 :                 col++;
     380             :             }
     381             : 
     382             :             /* keep scanning subplan to make sure there's only one tuple */
     383         240 :             continue;
     384             :         }
     385             : 
     386       15750 :         if (subLinkType == ARRAY_SUBLINK)
     387             :         {
     388             :             Datum       dvalue;
     389             :             bool        disnull;
     390             : 
     391        4674 :             found = true;
     392             :             /* stash away current value */
     393             :             Assert(subplan->firstColType == TupleDescAttr(tdesc, 0)->atttypid);
     394        4674 :             dvalue = slot_getattr(slot, 1, &disnull);
     395        4674 :             astate = accumArrayResultAny(astate, dvalue, disnull,
     396             :                                          subplan->firstColType, oldcontext);
     397             :             /* keep scanning subplan to collect all values */
     398        4674 :             continue;
     399             :         }
     400             : 
     401             :         /* cannot allow multiple input tuples for ROWCOMPARE sublink either */
     402       11076 :         if (subLinkType == ROWCOMPARE_SUBLINK && found)
     403           0 :             ereport(ERROR,
     404             :                     (errcode(ERRCODE_CARDINALITY_VIOLATION),
     405             :                      errmsg("more than one row returned by a subquery used as an expression")));
     406             : 
     407       11076 :         found = true;
     408             : 
     409             :         /*
     410             :          * For ALL, ANY, and ROWCOMPARE sublinks, load up the Params
     411             :          * representing the columns of the sub-select, and then evaluate the
     412             :          * combining expression.
     413             :          */
     414       11076 :         col = 1;
     415       32910 :         foreach(plst, subplan->paramIds)
     416             :         {
     417       21834 :             int         paramid = lfirst_int(plst);
     418             :             ParamExecData *prmdata;
     419             : 
     420       21834 :             prmdata = &(econtext->ecxt_param_exec_vals[paramid]);
     421             :             Assert(prmdata->execPlan == NULL);
     422       21834 :             prmdata->value = slot_getattr(slot, col, &(prmdata->isnull));
     423       21834 :             col++;
     424             :         }
     425             : 
     426       11076 :         rowresult = ExecEvalExprSwitchContext(node->testexpr, econtext,
     427             :                                               &rownull);
     428             : 
     429       11076 :         if (subLinkType == ANY_SUBLINK)
     430             :         {
     431             :             /* combine across rows per OR semantics */
     432       10938 :             if (rownull)
     433           0 :                 *isNull = true;
     434       10938 :             else if (DatumGetBool(rowresult))
     435             :             {
     436         108 :                 result = BoolGetDatum(true);
     437         108 :                 *isNull = false;
     438         108 :                 break;          /* needn't look at any more rows */
     439             :             }
     440             :         }
     441         138 :         else if (subLinkType == ALL_SUBLINK)
     442             :         {
     443             :             /* combine across rows per AND semantics */
     444          90 :             if (rownull)
     445           0 :                 *isNull = true;
     446          90 :             else if (!DatumGetBool(rowresult))
     447             :             {
     448          24 :                 result = BoolGetDatum(false);
     449          24 :                 *isNull = false;
     450          24 :                 break;          /* needn't look at any more rows */
     451             :             }
     452             :         }
     453             :         else
     454             :         {
     455             :             /* must be ROWCOMPARE_SUBLINK */
     456          48 :             result = rowresult;
     457          48 :             *isNull = rownull;
     458             :         }
     459             :     }
     460             : 
     461     1307594 :     MemoryContextSwitchTo(oldcontext);
     462             : 
     463     1307594 :     if (subLinkType == ARRAY_SUBLINK)
     464             :     {
     465             :         /* We return the result in the caller's context */
     466       44514 :         result = makeArrayResultAny(astate, oldcontext, true);
     467             :     }
     468     1263080 :     else if (!found)
     469             :     {
     470             :         /*
     471             :          * deal with empty subplan result.  result/isNull were previously
     472             :          * initialized correctly for all sublink types except EXPR and
     473             :          * ROWCOMPARE; for those, return NULL.
     474             :          */
     475      975108 :         if (subLinkType == EXPR_SUBLINK ||
     476             :             subLinkType == ROWCOMPARE_SUBLINK)
     477             :         {
     478       19062 :             result = (Datum) 0;
     479       19062 :             *isNull = true;
     480             :         }
     481      956046 :         else if (subLinkType == MULTIEXPR_SUBLINK)
     482             :         {
     483             :             /* We don't care about function result, but set the setParams */
     484          18 :             foreach(l, subplan->setParam)
     485             :             {
     486          12 :                 int         paramid = lfirst_int(l);
     487             :                 ParamExecData *prmdata;
     488             : 
     489          12 :                 prmdata = &(econtext->ecxt_param_exec_vals[paramid]);
     490             :                 Assert(prmdata->execPlan == NULL);
     491          12 :                 prmdata->value = (Datum) 0;
     492          12 :                 prmdata->isnull = true;
     493             :             }
     494             :         }
     495             :     }
     496             : 
     497     1307594 :     return result;
     498             : }
     499             : 
     500             : /*
     501             :  * buildSubPlanHash: load hash table by scanning subplan output.
     502             :  */
     503             : static void
     504        1372 : buildSubPlanHash(SubPlanState *node, ExprContext *econtext)
     505             : {
     506        1372 :     SubPlan    *subplan = node->subplan;
     507        1372 :     PlanState  *planstate = node->planstate;
     508        1372 :     int         ncols = node->numCols;
     509        1372 :     ExprContext *innerecontext = node->innerecontext;
     510             :     MemoryContext oldcontext;
     511             :     long        nbuckets;
     512             :     TupleTableSlot *slot;
     513             : 
     514             :     Assert(subplan->subLinkType == ANY_SUBLINK);
     515             : 
     516             :     /*
     517             :      * If we already had any hash tables, reset 'em; otherwise create empty
     518             :      * hash table(s).
     519             :      *
     520             :      * If we need to distinguish accurately between FALSE and UNKNOWN (i.e.,
     521             :      * NULL) results of the IN operation, then we have to store subplan output
     522             :      * rows that are partly or wholly NULL.  We store such rows in a separate
     523             :      * hash table that we expect will be much smaller than the main table. (We
     524             :      * can use hashing to eliminate partly-null rows that are not distinct. We
     525             :      * keep them separate to minimize the cost of the inevitable full-table
     526             :      * searches; see findPartialMatch.)
     527             :      *
     528             :      * If it's not necessary to distinguish FALSE and UNKNOWN, then we don't
     529             :      * need to store subplan output rows that contain NULL.
     530             :      */
     531        1372 :     MemoryContextReset(node->hashtablecxt);
     532        1372 :     node->havehashrows = false;
     533        1372 :     node->havenullrows = false;
     534             : 
     535        1372 :     nbuckets = clamp_cardinality_to_long(planstate->plan->plan_rows);
     536        1372 :     if (nbuckets < 1)
     537           0 :         nbuckets = 1;
     538             : 
     539        1372 :     if (node->hashtable)
     540         594 :         ResetTupleHashTable(node->hashtable);
     541             :     else
     542         778 :         node->hashtable = BuildTupleHashTableExt(node->parent,
     543             :                                                  node->descRight,
     544             :                                                  ncols,
     545             :                                                  node->keyColIdx,
     546         778 :                                                  node->tab_eq_funcoids,
     547             :                                                  node->tab_hash_funcs,
     548             :                                                  node->tab_collations,
     549             :                                                  nbuckets,
     550             :                                                  0,
     551         778 :                                                  node->planstate->state->es_query_cxt,
     552             :                                                  node->hashtablecxt,
     553             :                                                  node->hashtempcxt,
     554             :                                                  false);
     555             : 
     556        1372 :     if (!subplan->unknownEqFalse)
     557             :     {
     558         762 :         if (ncols == 1)
     559         714 :             nbuckets = 1;       /* there can only be one entry */
     560             :         else
     561             :         {
     562          48 :             nbuckets /= 16;
     563          48 :             if (nbuckets < 1)
     564           0 :                 nbuckets = 1;
     565             :         }
     566             : 
     567         762 :         if (node->hashnulls)
     568         594 :             ResetTupleHashTable(node->hashnulls);
     569             :         else
     570         168 :             node->hashnulls = BuildTupleHashTableExt(node->parent,
     571             :                                                      node->descRight,
     572             :                                                      ncols,
     573             :                                                      node->keyColIdx,
     574         168 :                                                      node->tab_eq_funcoids,
     575             :                                                      node->tab_hash_funcs,
     576             :                                                      node->tab_collations,
     577             :                                                      nbuckets,
     578             :                                                      0,
     579         168 :                                                      node->planstate->state->es_query_cxt,
     580             :                                                      node->hashtablecxt,
     581             :                                                      node->hashtempcxt,
     582             :                                                      false);
     583             :     }
     584             :     else
     585         610 :         node->hashnulls = NULL;
     586             : 
     587             :     /*
     588             :      * We are probably in a short-lived expression-evaluation context. Switch
     589             :      * to the per-query context for manipulating the child plan.
     590             :      */
     591        1372 :     oldcontext = MemoryContextSwitchTo(econtext->ecxt_per_query_memory);
     592             : 
     593             :     /*
     594             :      * Reset subplan to start.
     595             :      */
     596        1372 :     ExecReScan(planstate);
     597             : 
     598             :     /*
     599             :      * Scan the subplan and load the hash table(s).  Note that when there are
     600             :      * duplicate rows coming out of the sub-select, only one copy is stored.
     601             :      */
     602      182742 :     for (slot = ExecProcNode(planstate);
     603      182064 :          !TupIsNull(slot);
     604      181370 :          slot = ExecProcNode(planstate))
     605             :     {
     606      181376 :         int         col = 1;
     607             :         ListCell   *plst;
     608             :         bool        isnew;
     609             : 
     610             :         /*
     611             :          * Load up the Params representing the raw sub-select outputs, then
     612             :          * form the projection tuple to store in the hashtable.
     613             :          */
     614      416788 :         foreach(plst, subplan->paramIds)
     615             :         {
     616      235412 :             int         paramid = lfirst_int(plst);
     617             :             ParamExecData *prmdata;
     618             : 
     619      235412 :             prmdata = &(innerecontext->ecxt_param_exec_vals[paramid]);
     620             :             Assert(prmdata->execPlan == NULL);
     621      235412 :             prmdata->value = slot_getattr(slot, col,
     622             :                                           &(prmdata->isnull));
     623      235412 :             col++;
     624             :         }
     625      181376 :         slot = ExecProject(node->projRight);
     626             : 
     627             :         /*
     628             :          * If result contains any nulls, store separately or not at all.
     629             :          */
     630      181376 :         if (slotNoNulls(slot))
     631             :         {
     632      181352 :             (void) LookupTupleHashEntry(node->hashtable, slot, &isnew, NULL);
     633      181346 :             node->havehashrows = true;
     634             :         }
     635          24 :         else if (node->hashnulls)
     636             :         {
     637          24 :             (void) LookupTupleHashEntry(node->hashnulls, slot, &isnew, NULL);
     638          24 :             node->havenullrows = true;
     639             :         }
     640             : 
     641             :         /*
     642             :          * Reset innerecontext after each inner tuple to free any memory used
     643             :          * during ExecProject.
     644             :          */
     645      181370 :         ResetExprContext(innerecontext);
     646             :     }
     647             : 
     648             :     /*
     649             :      * Since the projected tuples are in the sub-query's context and not the
     650             :      * main context, we'd better clear the tuple slot before there's any
     651             :      * chance of a reset of the sub-query's context.  Else we will have the
     652             :      * potential for a double free attempt.  (XXX possibly no longer needed,
     653             :      * but can't hurt.)
     654             :      */
     655        1366 :     ExecClearTuple(node->projRight->pi_state.resultslot);
     656             : 
     657        1366 :     MemoryContextSwitchTo(oldcontext);
     658        1366 : }
     659             : 
     660             : /*
     661             :  * execTuplesUnequal
     662             :  *      Return true if two tuples are definitely unequal in the indicated
     663             :  *      fields.
     664             :  *
     665             :  * Nulls are neither equal nor unequal to anything else.  A true result
     666             :  * is obtained only if there are non-null fields that compare not-equal.
     667             :  *
     668             :  * slot1, slot2: the tuples to compare (must have same columns!)
     669             :  * numCols: the number of attributes to be examined
     670             :  * matchColIdx: array of attribute column numbers
     671             :  * eqFunctions: array of fmgr lookup info for the equality functions to use
     672             :  * evalContext: short-term memory context for executing the functions
     673             :  */
     674             : static bool
     675          78 : execTuplesUnequal(TupleTableSlot *slot1,
     676             :                   TupleTableSlot *slot2,
     677             :                   int numCols,
     678             :                   AttrNumber *matchColIdx,
     679             :                   FmgrInfo *eqfunctions,
     680             :                   const Oid *collations,
     681             :                   MemoryContext evalContext)
     682             : {
     683             :     MemoryContext oldContext;
     684             :     bool        result;
     685             :     int         i;
     686             : 
     687             :     /* Reset and switch into the temp context. */
     688          78 :     MemoryContextReset(evalContext);
     689          78 :     oldContext = MemoryContextSwitchTo(evalContext);
     690             : 
     691             :     /*
     692             :      * We cannot report a match without checking all the fields, but we can
     693             :      * report a non-match as soon as we find unequal fields.  So, start
     694             :      * comparing at the last field (least significant sort key). That's the
     695             :      * most likely to be different if we are dealing with sorted input.
     696             :      */
     697          78 :     result = false;
     698             : 
     699         192 :     for (i = numCols; --i >= 0;)
     700             :     {
     701         156 :         AttrNumber  att = matchColIdx[i];
     702             :         Datum       attr1,
     703             :                     attr2;
     704             :         bool        isNull1,
     705             :                     isNull2;
     706             : 
     707         156 :         attr1 = slot_getattr(slot1, att, &isNull1);
     708             : 
     709         156 :         if (isNull1)
     710          78 :             continue;           /* can't prove anything here */
     711             : 
     712         114 :         attr2 = slot_getattr(slot2, att, &isNull2);
     713             : 
     714         114 :         if (isNull2)
     715          36 :             continue;           /* can't prove anything here */
     716             : 
     717             :         /* Apply the type-specific equality function */
     718          78 :         if (!DatumGetBool(FunctionCall2Coll(&eqfunctions[i],
     719          78 :                                             collations[i],
     720             :                                             attr1, attr2)))
     721             :         {
     722          42 :             result = true;      /* they are unequal */
     723          42 :             break;
     724             :         }
     725             :     }
     726             : 
     727          78 :     MemoryContextSwitchTo(oldContext);
     728             : 
     729          78 :     return result;
     730             : }
     731             : 
     732             : /*
     733             :  * findPartialMatch: does the hashtable contain an entry that is not
     734             :  * provably distinct from the tuple?
     735             :  *
     736             :  * We have to scan the whole hashtable; we can't usefully use hashkeys
     737             :  * to guide probing, since we might get partial matches on tuples with
     738             :  * hashkeys quite unrelated to what we'd get from the given tuple.
     739             :  *
     740             :  * Caller must provide the equality functions to use, since in cross-type
     741             :  * cases these are different from the hashtable's internal functions.
     742             :  */
     743             : static bool
     744          78 : findPartialMatch(TupleHashTable hashtable, TupleTableSlot *slot,
     745             :                  FmgrInfo *eqfunctions)
     746             : {
     747          78 :     int         numCols = hashtable->numCols;
     748          78 :     AttrNumber *keyColIdx = hashtable->keyColIdx;
     749             :     TupleHashIterator hashiter;
     750             :     TupleHashEntry entry;
     751             : 
     752          78 :     InitTupleHashIterator(hashtable, &hashiter);
     753         120 :     while ((entry = ScanTupleHashTable(hashtable, &hashiter)) != NULL)
     754             :     {
     755          78 :         CHECK_FOR_INTERRUPTS();
     756             : 
     757          78 :         ExecStoreMinimalTuple(entry->firstTuple, hashtable->tableslot, false);
     758          78 :         if (!execTuplesUnequal(slot, hashtable->tableslot,
     759             :                                numCols, keyColIdx,
     760             :                                eqfunctions,
     761          78 :                                hashtable->tab_collations,
     762             :                                hashtable->tempcxt))
     763             :         {
     764             :             TermTupleHashIterator(&hashiter);
     765          36 :             return true;
     766             :         }
     767             :     }
     768             :     /* No TermTupleHashIterator call needed here */
     769          42 :     return false;
     770             : }
     771             : 
     772             : /*
     773             :  * slotAllNulls: is the slot completely NULL?
     774             :  *
     775             :  * This does not test for dropped columns, which is OK because we only
     776             :  * use it on projected tuples.
     777             :  */
     778             : static bool
     779          36 : slotAllNulls(TupleTableSlot *slot)
     780             : {
     781          36 :     int         ncols = slot->tts_tupleDescriptor->natts;
     782             :     int         i;
     783             : 
     784          36 :     for (i = 1; i <= ncols; i++)
     785             :     {
     786          36 :         if (!slot_attisnull(slot, i))
     787          36 :             return false;
     788             :     }
     789           0 :     return true;
     790             : }
     791             : 
     792             : /*
     793             :  * slotNoNulls: is the slot entirely not NULL?
     794             :  *
     795             :  * This does not test for dropped columns, which is OK because we only
     796             :  * use it on projected tuples.
     797             :  */
     798             : static bool
     799     1005902 : slotNoNulls(TupleTableSlot *slot)
     800             : {
     801     1005902 :     int         ncols = slot->tts_tupleDescriptor->natts;
     802             :     int         i;
     803             : 
     804     2125966 :     for (i = 1; i <= ncols; i++)
     805             :     {
     806     1120124 :         if (slot_attisnull(slot, i))
     807          60 :             return false;
     808             :     }
     809     1005842 :     return true;
     810             : }
     811             : 
     812             : /* ----------------------------------------------------------------
     813             :  *      ExecInitSubPlan
     814             :  *
     815             :  * Create a SubPlanState for a SubPlan; this is the SubPlan-specific part
     816             :  * of ExecInitExpr().  We split it out so that it can be used for InitPlans
     817             :  * as well as regular SubPlans.  Note that we don't link the SubPlan into
     818             :  * the parent's subPlan list, because that shouldn't happen for InitPlans.
     819             :  * Instead, ExecInitExpr() does that one part.
     820             :  * ----------------------------------------------------------------
     821             :  */
     822             : SubPlanState *
     823       36028 : ExecInitSubPlan(SubPlan *subplan, PlanState *parent)
     824             : {
     825       36028 :     SubPlanState *sstate = makeNode(SubPlanState);
     826       36028 :     EState     *estate = parent->state;
     827             : 
     828       36028 :     sstate->subplan = subplan;
     829             : 
     830             :     /* Link the SubPlanState to already-initialized subplan */
     831       72056 :     sstate->planstate = (PlanState *) list_nth(estate->es_subplanstates,
     832       36028 :                                                subplan->plan_id - 1);
     833             : 
     834             :     /*
     835             :      * This check can fail if the planner mistakenly puts a parallel-unsafe
     836             :      * subplan into a parallelized subquery; see ExecSerializePlan.
     837             :      */
     838       36028 :     if (sstate->planstate == NULL)
     839           0 :         elog(ERROR, "subplan \"%s\" was not initialized",
     840             :              subplan->plan_name);
     841             : 
     842             :     /* Link to parent's state, too */
     843       36028 :     sstate->parent = parent;
     844             : 
     845             :     /* Initialize subexpressions */
     846       36028 :     sstate->testexpr = ExecInitExpr((Expr *) subplan->testexpr, parent);
     847       36028 :     sstate->args = ExecInitExprList(subplan->args, parent);
     848             : 
     849             :     /*
     850             :      * initialize my state
     851             :      */
     852       36028 :     sstate->curTuple = NULL;
     853       36028 :     sstate->curArray = PointerGetDatum(NULL);
     854       36028 :     sstate->projLeft = NULL;
     855       36028 :     sstate->projRight = NULL;
     856       36028 :     sstate->hashtable = NULL;
     857       36028 :     sstate->hashnulls = NULL;
     858       36028 :     sstate->hashtablecxt = NULL;
     859       36028 :     sstate->hashtempcxt = NULL;
     860       36028 :     sstate->innerecontext = NULL;
     861       36028 :     sstate->keyColIdx = NULL;
     862       36028 :     sstate->tab_eq_funcoids = NULL;
     863       36028 :     sstate->tab_hash_funcs = NULL;
     864       36028 :     sstate->tab_eq_funcs = NULL;
     865       36028 :     sstate->tab_collations = NULL;
     866       36028 :     sstate->lhs_hash_funcs = NULL;
     867       36028 :     sstate->cur_eq_funcs = NULL;
     868             : 
     869             :     /*
     870             :      * If this is an initplan, it has output parameters that the parent plan
     871             :      * will use, so mark those parameters as needing evaluation.  We don't
     872             :      * actually run the subplan until we first need one of its outputs.
     873             :      *
     874             :      * A CTE subplan's output parameter is never to be evaluated in the normal
     875             :      * way, so skip this in that case.
     876             :      *
     877             :      * Note that we don't set parent->chgParam here: the parent plan hasn't
     878             :      * been run yet, so no need to force it to re-run.
     879             :      */
     880       36028 :     if (subplan->setParam != NIL && subplan->parParam == NIL &&
     881       12320 :         subplan->subLinkType != CTE_SUBLINK)
     882             :     {
     883             :         ListCell   *lst;
     884             : 
     885       20640 :         foreach(lst, subplan->setParam)
     886             :         {
     887       10344 :             int         paramid = lfirst_int(lst);
     888       10344 :             ParamExecData *prm = &(estate->es_param_exec_vals[paramid]);
     889             : 
     890       10344 :             prm->execPlan = sstate;
     891             :         }
     892             :     }
     893             : 
     894             :     /*
     895             :      * If we are going to hash the subquery output, initialize relevant stuff.
     896             :      * (We don't create the hashtable until needed, though.)
     897             :      */
     898       36028 :     if (subplan->useHashTable)
     899             :     {
     900             :         int         ncols,
     901             :                     i;
     902             :         TupleDesc   tupDescLeft;
     903             :         TupleDesc   tupDescRight;
     904             :         Oid        *cross_eq_funcoids;
     905             :         TupleTableSlot *slot;
     906             :         List       *oplist,
     907             :                    *lefttlist,
     908             :                    *righttlist;
     909             :         ListCell   *l;
     910             : 
     911             :         /* We need a memory context to hold the hash table(s) */
     912         978 :         sstate->hashtablecxt =
     913         978 :             AllocSetContextCreate(CurrentMemoryContext,
     914             :                                   "Subplan HashTable Context",
     915             :                                   ALLOCSET_DEFAULT_SIZES);
     916             :         /* and a small one for the hash tables to use as temp storage */
     917         978 :         sstate->hashtempcxt =
     918         978 :             AllocSetContextCreate(CurrentMemoryContext,
     919             :                                   "Subplan HashTable Temp Context",
     920             :                                   ALLOCSET_SMALL_SIZES);
     921             :         /* and a short-lived exprcontext for function evaluation */
     922         978 :         sstate->innerecontext = CreateExprContext(estate);
     923             : 
     924             :         /*
     925             :          * We use ExecProject to evaluate the lefthand and righthand
     926             :          * expression lists and form tuples.  (You might think that we could
     927             :          * use the sub-select's output tuples directly, but that is not the
     928             :          * case if we had to insert any run-time coercions of the sub-select's
     929             :          * output datatypes; anyway this avoids storing any resjunk columns
     930             :          * that might be in the sub-select's output.)  Run through the
     931             :          * combining expressions to build tlists for the lefthand and
     932             :          * righthand sides.
     933             :          *
     934             :          * We also extract the combining operators themselves to initialize
     935             :          * the equality and hashing functions for the hash tables.
     936             :          */
     937         978 :         if (IsA(subplan->testexpr, OpExpr))
     938             :         {
     939             :             /* single combining operator */
     940         840 :             oplist = list_make1(subplan->testexpr);
     941             :         }
     942         138 :         else if (is_andclause(subplan->testexpr))
     943             :         {
     944             :             /* multiple combining operators */
     945         138 :             oplist = castNode(BoolExpr, subplan->testexpr)->args;
     946             :         }
     947             :         else
     948             :         {
     949             :             /* shouldn't see anything else in a hashable subplan */
     950           0 :             elog(ERROR, "unrecognized testexpr type: %d",
     951             :                  (int) nodeTag(subplan->testexpr));
     952             :             oplist = NIL;       /* keep compiler quiet */
     953             :         }
     954         978 :         ncols = list_length(oplist);
     955             : 
     956         978 :         lefttlist = righttlist = NIL;
     957         978 :         sstate->numCols = ncols;
     958         978 :         sstate->keyColIdx = (AttrNumber *) palloc(ncols * sizeof(AttrNumber));
     959         978 :         sstate->tab_eq_funcoids = (Oid *) palloc(ncols * sizeof(Oid));
     960         978 :         sstate->tab_collations = (Oid *) palloc(ncols * sizeof(Oid));
     961         978 :         sstate->tab_hash_funcs = (FmgrInfo *) palloc(ncols * sizeof(FmgrInfo));
     962         978 :         sstate->tab_eq_funcs = (FmgrInfo *) palloc(ncols * sizeof(FmgrInfo));
     963         978 :         sstate->lhs_hash_funcs = (FmgrInfo *) palloc(ncols * sizeof(FmgrInfo));
     964         978 :         sstate->cur_eq_funcs = (FmgrInfo *) palloc(ncols * sizeof(FmgrInfo));
     965             :         /* we'll need the cross-type equality fns below, but not in sstate */
     966         978 :         cross_eq_funcoids = (Oid *) palloc(ncols * sizeof(Oid));
     967             : 
     968         978 :         i = 1;
     969        2094 :         foreach(l, oplist)
     970             :         {
     971        1116 :             OpExpr     *opexpr = lfirst_node(OpExpr, l);
     972             :             Expr       *expr;
     973             :             TargetEntry *tle;
     974             :             Oid         rhs_eq_oper;
     975             :             Oid         left_hashfn;
     976             :             Oid         right_hashfn;
     977             : 
     978             :             Assert(list_length(opexpr->args) == 2);
     979             : 
     980             :             /* Process lefthand argument */
     981        1116 :             expr = (Expr *) linitial(opexpr->args);
     982        1116 :             tle = makeTargetEntry(expr,
     983             :                                   i,
     984             :                                   NULL,
     985             :                                   false);
     986        1116 :             lefttlist = lappend(lefttlist, tle);
     987             : 
     988             :             /* Process righthand argument */
     989        1116 :             expr = (Expr *) lsecond(opexpr->args);
     990        1116 :             tle = makeTargetEntry(expr,
     991             :                                   i,
     992             :                                   NULL,
     993             :                                   false);
     994        1116 :             righttlist = lappend(righttlist, tle);
     995             : 
     996             :             /* Lookup the equality function (potentially cross-type) */
     997        1116 :             cross_eq_funcoids[i - 1] = opexpr->opfuncid;
     998        1116 :             fmgr_info(opexpr->opfuncid, &sstate->cur_eq_funcs[i - 1]);
     999        1116 :             fmgr_info_set_expr((Node *) opexpr, &sstate->cur_eq_funcs[i - 1]);
    1000             : 
    1001             :             /* Look up the equality function for the RHS type */
    1002        1116 :             if (!get_compatible_hash_operators(opexpr->opno,
    1003             :                                                NULL, &rhs_eq_oper))
    1004           0 :                 elog(ERROR, "could not find compatible hash operator for operator %u",
    1005             :                      opexpr->opno);
    1006        1116 :             sstate->tab_eq_funcoids[i - 1] = get_opcode(rhs_eq_oper);
    1007        1116 :             fmgr_info(sstate->tab_eq_funcoids[i - 1],
    1008        1116 :                       &sstate->tab_eq_funcs[i - 1]);
    1009             : 
    1010             :             /* Lookup the associated hash functions */
    1011        1116 :             if (!get_op_hash_functions(opexpr->opno,
    1012             :                                        &left_hashfn, &right_hashfn))
    1013           0 :                 elog(ERROR, "could not find hash function for hash operator %u",
    1014             :                      opexpr->opno);
    1015        1116 :             fmgr_info(left_hashfn, &sstate->lhs_hash_funcs[i - 1]);
    1016        1116 :             fmgr_info(right_hashfn, &sstate->tab_hash_funcs[i - 1]);
    1017             : 
    1018             :             /* Set collation */
    1019        1116 :             sstate->tab_collations[i - 1] = opexpr->inputcollid;
    1020             : 
    1021             :             /* keyColIdx is just column numbers 1..n */
    1022        1116 :             sstate->keyColIdx[i - 1] = i;
    1023             : 
    1024        1116 :             i++;
    1025             :         }
    1026             : 
    1027             :         /*
    1028             :          * Construct tupdescs, slots and projection nodes for left and right
    1029             :          * sides.  The lefthand expressions will be evaluated in the parent
    1030             :          * plan node's exprcontext, which we don't have access to here.
    1031             :          * Fortunately we can just pass NULL for now and fill it in later
    1032             :          * (hack alert!).  The righthand expressions will be evaluated in our
    1033             :          * own innerecontext.
    1034             :          */
    1035         978 :         tupDescLeft = ExecTypeFromTL(lefttlist);
    1036         978 :         slot = ExecInitExtraTupleSlot(estate, tupDescLeft, &TTSOpsVirtual);
    1037         978 :         sstate->projLeft = ExecBuildProjectionInfo(lefttlist,
    1038             :                                                    NULL,
    1039             :                                                    slot,
    1040             :                                                    parent,
    1041             :                                                    NULL);
    1042             : 
    1043         978 :         sstate->descRight = tupDescRight = ExecTypeFromTL(righttlist);
    1044         978 :         slot = ExecInitExtraTupleSlot(estate, tupDescRight, &TTSOpsVirtual);
    1045        1956 :         sstate->projRight = ExecBuildProjectionInfo(righttlist,
    1046             :                                                     sstate->innerecontext,
    1047             :                                                     slot,
    1048         978 :                                                     sstate->planstate,
    1049             :                                                     NULL);
    1050             : 
    1051             :         /*
    1052             :          * Create comparator for lookups of rows in the table (potentially
    1053             :          * cross-type comparisons).
    1054             :          */
    1055         978 :         sstate->cur_eq_comp = ExecBuildGroupingEqual(tupDescLeft, tupDescRight,
    1056             :                                                      &TTSOpsVirtual, &TTSOpsMinimalTuple,
    1057             :                                                      ncols,
    1058         978 :                                                      sstate->keyColIdx,
    1059             :                                                      cross_eq_funcoids,
    1060         978 :                                                      sstate->tab_collations,
    1061             :                                                      parent);
    1062             :     }
    1063             : 
    1064       36028 :     return sstate;
    1065             : }
    1066             : 
    1067             : /* ----------------------------------------------------------------
    1068             :  *      ExecSetParamPlan
    1069             :  *
    1070             :  *      Executes a subplan and sets its output parameters.
    1071             :  *
    1072             :  * This is called from ExecEvalParamExec() when the value of a PARAM_EXEC
    1073             :  * parameter is requested and the param's execPlan field is set (indicating
    1074             :  * that the param has not yet been evaluated).  This allows lazy evaluation
    1075             :  * of initplans: we don't run the subplan until/unless we need its output.
    1076             :  * Note that this routine MUST clear the execPlan fields of the plan's
    1077             :  * output parameters after evaluating them!
    1078             :  *
    1079             :  * The results of this function are stored in the EState associated with the
    1080             :  * ExprContext (particularly, its ecxt_param_exec_vals); any pass-by-ref
    1081             :  * result Datums are allocated in the EState's per-query memory.  The passed
    1082             :  * econtext can be any ExprContext belonging to that EState; which one is
    1083             :  * important only to the extent that the ExprContext's per-tuple memory
    1084             :  * context is used to evaluate any parameters passed down to the subplan.
    1085             :  * (Thus in principle, the shorter-lived the ExprContext the better, since
    1086             :  * that data isn't needed after we return.  In practice, because initplan
    1087             :  * parameters are never more complex than Vars, Aggrefs, etc, evaluating them
    1088             :  * currently never leaks any memory anyway.)
    1089             :  * ----------------------------------------------------------------
    1090             :  */
    1091             : void
    1092        8376 : ExecSetParamPlan(SubPlanState *node, ExprContext *econtext)
    1093             : {
    1094        8376 :     SubPlan    *subplan = node->subplan;
    1095        8376 :     PlanState  *planstate = node->planstate;
    1096        8376 :     SubLinkType subLinkType = subplan->subLinkType;
    1097        8376 :     EState     *estate = planstate->state;
    1098        8376 :     ScanDirection dir = estate->es_direction;
    1099             :     MemoryContext oldcontext;
    1100             :     TupleTableSlot *slot;
    1101             :     ListCell   *l;
    1102        8376 :     bool        found = false;
    1103        8376 :     ArrayBuildStateAny *astate = NULL;
    1104             : 
    1105        8376 :     if (subLinkType == ANY_SUBLINK ||
    1106             :         subLinkType == ALL_SUBLINK)
    1107           0 :         elog(ERROR, "ANY/ALL subselect unsupported as initplan");
    1108        8376 :     if (subLinkType == CTE_SUBLINK)
    1109           0 :         elog(ERROR, "CTE subplans should not be executed via ExecSetParamPlan");
    1110        8376 :     if (subplan->parParam || node->args)
    1111           0 :         elog(ERROR, "correlated subplans should not be executed via ExecSetParamPlan");
    1112             : 
    1113             :     /*
    1114             :      * Enforce forward scan direction regardless of caller. It's hard but not
    1115             :      * impossible to get here in backward scan, so make it work anyway.
    1116             :      */
    1117        8376 :     estate->es_direction = ForwardScanDirection;
    1118             : 
    1119             :     /* Initialize ArrayBuildStateAny in caller's context, if needed */
    1120        8376 :     if (subLinkType == ARRAY_SUBLINK)
    1121          80 :         astate = initArrayResultAny(subplan->firstColType,
    1122             :                                     CurrentMemoryContext, true);
    1123             : 
    1124             :     /*
    1125             :      * Must switch to per-query memory context.
    1126             :      */
    1127        8376 :     oldcontext = MemoryContextSwitchTo(econtext->ecxt_per_query_memory);
    1128             : 
    1129             :     /*
    1130             :      * Run the plan.  (If it needs to be rescanned, the first ExecProcNode
    1131             :      * call will take care of that.)
    1132             :      */
    1133       28020 :     for (slot = ExecProcNode(planstate);
    1134       25674 :          !TupIsNull(slot);
    1135       19644 :          slot = ExecProcNode(planstate))
    1136             :     {
    1137       19752 :         TupleDesc   tdesc = slot->tts_tupleDescriptor;
    1138       19752 :         int         i = 1;
    1139             : 
    1140       19752 :         if (subLinkType == EXISTS_SUBLINK)
    1141             :         {
    1142             :             /* There can be only one setParam... */
    1143          90 :             int         paramid = linitial_int(subplan->setParam);
    1144          90 :             ParamExecData *prm = &(econtext->ecxt_param_exec_vals[paramid]);
    1145             : 
    1146          90 :             prm->execPlan = NULL;
    1147          90 :             prm->value = BoolGetDatum(true);
    1148          90 :             prm->isnull = false;
    1149          90 :             found = true;
    1150          90 :             break;
    1151             :         }
    1152             : 
    1153       19662 :         if (subLinkType == ARRAY_SUBLINK)
    1154             :         {
    1155             :             Datum       dvalue;
    1156             :             bool        disnull;
    1157             : 
    1158       12142 :             found = true;
    1159             :             /* stash away current value */
    1160             :             Assert(subplan->firstColType == TupleDescAttr(tdesc, 0)->atttypid);
    1161       12142 :             dvalue = slot_getattr(slot, 1, &disnull);
    1162       12142 :             astate = accumArrayResultAny(astate, dvalue, disnull,
    1163             :                                          subplan->firstColType, oldcontext);
    1164             :             /* keep scanning subplan to collect all values */
    1165       12142 :             continue;
    1166             :         }
    1167             : 
    1168        7520 :         if (found &&
    1169          12 :             (subLinkType == EXPR_SUBLINK ||
    1170           6 :              subLinkType == MULTIEXPR_SUBLINK ||
    1171             :              subLinkType == ROWCOMPARE_SUBLINK))
    1172          18 :             ereport(ERROR,
    1173             :                     (errcode(ERRCODE_CARDINALITY_VIOLATION),
    1174             :                      errmsg("more than one row returned by a subquery used as an expression")));
    1175             : 
    1176        7502 :         found = true;
    1177             : 
    1178             :         /*
    1179             :          * We need to copy the subplan's tuple into our own context, in case
    1180             :          * any of the params are pass-by-ref type --- the pointers stored in
    1181             :          * the param structs will point at this copied tuple! node->curTuple
    1182             :          * keeps track of the copied tuple for eventual freeing.
    1183             :          */
    1184        7502 :         if (node->curTuple)
    1185         370 :             heap_freetuple(node->curTuple);
    1186        7502 :         node->curTuple = ExecCopySlotHeapTuple(slot);
    1187             : 
    1188             :         /*
    1189             :          * Now set all the setParam params from the columns of the tuple
    1190             :          */
    1191       15040 :         foreach(l, subplan->setParam)
    1192             :         {
    1193        7538 :             int         paramid = lfirst_int(l);
    1194        7538 :             ParamExecData *prm = &(econtext->ecxt_param_exec_vals[paramid]);
    1195             : 
    1196        7538 :             prm->execPlan = NULL;
    1197        7538 :             prm->value = heap_getattr(node->curTuple, i, tdesc,
    1198             :                                       &(prm->isnull));
    1199        7538 :             i++;
    1200             :         }
    1201             :     }
    1202             : 
    1203        8358 :     if (subLinkType == ARRAY_SUBLINK)
    1204             :     {
    1205             :         /* There can be only one setParam... */
    1206          80 :         int         paramid = linitial_int(subplan->setParam);
    1207          80 :         ParamExecData *prm = &(econtext->ecxt_param_exec_vals[paramid]);
    1208             : 
    1209             :         /*
    1210             :          * We build the result array in query context so it won't disappear;
    1211             :          * to avoid leaking memory across repeated calls, we have to remember
    1212             :          * the latest value, much as for curTuple above.
    1213             :          */
    1214          80 :         if (node->curArray != PointerGetDatum(NULL))
    1215           0 :             pfree(DatumGetPointer(node->curArray));
    1216          80 :         node->curArray = makeArrayResultAny(astate,
    1217             :                                             econtext->ecxt_per_query_memory,
    1218             :                                             true);
    1219          80 :         prm->execPlan = NULL;
    1220          80 :         prm->value = node->curArray;
    1221          80 :         prm->isnull = false;
    1222             :     }
    1223        8278 :     else if (!found)
    1224             :     {
    1225         704 :         if (subLinkType == EXISTS_SUBLINK)
    1226             :         {
    1227             :             /* There can be only one setParam... */
    1228         654 :             int         paramid = linitial_int(subplan->setParam);
    1229         654 :             ParamExecData *prm = &(econtext->ecxt_param_exec_vals[paramid]);
    1230             : 
    1231         654 :             prm->execPlan = NULL;
    1232         654 :             prm->value = BoolGetDatum(false);
    1233         654 :             prm->isnull = false;
    1234             :         }
    1235             :         else
    1236             :         {
    1237             :             /* For other sublink types, set all the output params to NULL */
    1238         106 :             foreach(l, subplan->setParam)
    1239             :             {
    1240          56 :                 int         paramid = lfirst_int(l);
    1241          56 :                 ParamExecData *prm = &(econtext->ecxt_param_exec_vals[paramid]);
    1242             : 
    1243          56 :                 prm->execPlan = NULL;
    1244          56 :                 prm->value = (Datum) 0;
    1245          56 :                 prm->isnull = true;
    1246             :             }
    1247             :         }
    1248             :     }
    1249             : 
    1250        8358 :     MemoryContextSwitchTo(oldcontext);
    1251             : 
    1252             :     /* restore scan direction */
    1253        8358 :     estate->es_direction = dir;
    1254        8358 : }
    1255             : 
    1256             : /*
    1257             :  * ExecSetParamPlanMulti
    1258             :  *
    1259             :  * Apply ExecSetParamPlan to evaluate any not-yet-evaluated initplan output
    1260             :  * parameters whose ParamIDs are listed in "params".  Any listed params that
    1261             :  * are not initplan outputs are ignored.
    1262             :  *
    1263             :  * As with ExecSetParamPlan, any ExprContext belonging to the current EState
    1264             :  * can be used, but in principle a shorter-lived ExprContext is better than a
    1265             :  * longer-lived one.
    1266             :  */
    1267             : void
    1268        1280 : ExecSetParamPlanMulti(const Bitmapset *params, ExprContext *econtext)
    1269             : {
    1270             :     int         paramid;
    1271             : 
    1272        1280 :     paramid = -1;
    1273        1688 :     while ((paramid = bms_next_member(params, paramid)) >= 0)
    1274             :     {
    1275         408 :         ParamExecData *prm = &(econtext->ecxt_param_exec_vals[paramid]);
    1276             : 
    1277         408 :         if (prm->execPlan != NULL)
    1278             :         {
    1279             :             /* Parameter not evaluated yet, so go do it */
    1280          34 :             ExecSetParamPlan(prm->execPlan, econtext);
    1281             :             /* ExecSetParamPlan should have processed this param... */
    1282             :             Assert(prm->execPlan == NULL);
    1283             :         }
    1284             :     }
    1285        1280 : }
    1286             : 
    1287             : /*
    1288             :  * Mark an initplan as needing recalculation
    1289             :  */
    1290             : void
    1291         932 : ExecReScanSetParamPlan(SubPlanState *node, PlanState *parent)
    1292             : {
    1293         932 :     PlanState  *planstate = node->planstate;
    1294         932 :     SubPlan    *subplan = node->subplan;
    1295         932 :     EState     *estate = parent->state;
    1296             :     ListCell   *l;
    1297             : 
    1298             :     /* sanity checks */
    1299         932 :     if (subplan->parParam != NIL)
    1300           0 :         elog(ERROR, "direct correlated subquery unsupported as initplan");
    1301         932 :     if (subplan->setParam == NIL)
    1302           0 :         elog(ERROR, "setParam list of initplan is empty");
    1303         932 :     if (bms_is_empty(planstate->plan->extParam))
    1304           0 :         elog(ERROR, "extParam set of initplan is empty");
    1305             : 
    1306             :     /*
    1307             :      * Don't actually re-scan: it'll happen inside ExecSetParamPlan if needed.
    1308             :      */
    1309             : 
    1310             :     /*
    1311             :      * Mark this subplan's output parameters as needing recalculation.
    1312             :      *
    1313             :      * CTE subplans are never executed via parameter recalculation; instead
    1314             :      * they get run when called by nodeCtescan.c.  So don't mark the output
    1315             :      * parameter of a CTE subplan as dirty, but do set the chgParam bit for it
    1316             :      * so that dependent plan nodes will get told to rescan.
    1317             :      */
    1318        1864 :     foreach(l, subplan->setParam)
    1319             :     {
    1320         932 :         int         paramid = lfirst_int(l);
    1321         932 :         ParamExecData *prm = &(estate->es_param_exec_vals[paramid]);
    1322             : 
    1323         932 :         if (subplan->subLinkType != CTE_SUBLINK)
    1324         636 :             prm->execPlan = node;
    1325             : 
    1326         932 :         parent->chgParam = bms_add_member(parent->chgParam, paramid);
    1327             :     }
    1328         932 : }

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