1 /*-------------------------------------------------------------------------
4 * top level executor interface routines
11 * The old ExecutorMain() has been replaced by ExecutorStart(),
12 * ExecutorRun() and ExecutorEnd()
14 * These three procedures are the external interfaces to the executor.
15 * In each case, the query descriptor is required as an argument.
17 * ExecutorStart() must be called at the beginning of execution of any
18 * query plan and ExecutorEnd() should always be called at the end of
19 * execution of a plan.
21 * ExecutorRun accepts direction and count arguments that specify whether
22 * the plan is to be executed forwards, backwards, and for how many tuples.
24 * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
25 * Portions Copyright (c) 1994, Regents of the University of California
29 * $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.210 2003/07/21 17:05:08 tgl Exp $
31 *-------------------------------------------------------------------------
35 #include "access/heapam.h"
36 #include "catalog/heap.h"
37 #include "catalog/namespace.h"
38 #include "commands/tablecmds.h"
39 #include "commands/trigger.h"
40 #include "executor/execdebug.h"
41 #include "executor/execdefs.h"
42 #include "miscadmin.h"
43 #include "optimizer/var.h"
44 #include "parser/parsetree.h"
45 #include "utils/acl.h"
46 #include "utils/lsyscache.h"
49 typedef struct execRowMark
56 typedef struct evalPlanQual
61 struct evalPlanQual *next; /* stack of active PlanQual plans */
62 struct evalPlanQual *free; /* list of free PlanQual plans */
65 /* decls for local routines only used within this module */
66 static void InitPlan(QueryDesc *queryDesc, bool explainOnly);
67 static void initResultRelInfo(ResultRelInfo *resultRelInfo,
68 Index resultRelationIndex,
71 static TupleTableSlot *ExecutePlan(EState *estate, PlanState *planstate,
74 ScanDirection direction,
76 static void ExecSelect(TupleTableSlot *slot,
79 static void ExecInsert(TupleTableSlot *slot, ItemPointer tupleid,
81 static void ExecDelete(TupleTableSlot *slot, ItemPointer tupleid,
83 static void ExecUpdate(TupleTableSlot *slot, ItemPointer tupleid,
85 static TupleTableSlot *EvalPlanQualNext(EState *estate);
86 static void EndEvalPlanQual(EState *estate);
87 static void ExecCheckRTEPerms(RangeTblEntry *rte, CmdType operation);
88 static void ExecCheckXactReadOnly(Query *parsetree, CmdType operation);
89 static void EvalPlanQualStart(evalPlanQual *epq, EState *estate,
90 evalPlanQual *priorepq);
91 static void EvalPlanQualStop(evalPlanQual *epq);
93 /* end of local decls */
96 /* ----------------------------------------------------------------
99 * This routine must be called at the beginning of any execution of any
102 * Takes a QueryDesc previously created by CreateQueryDesc (it's not real
103 * clear why we bother to separate the two functions, but...). The tupDesc
104 * field of the QueryDesc is filled in to describe the tuples that will be
105 * returned, and the internal fields (estate and planstate) are set up.
107 * If explainOnly is true, we are not actually intending to run the plan,
108 * only to set up for EXPLAIN; so skip unwanted side-effects.
110 * NB: the CurrentMemoryContext when this is called will become the parent
111 * of the per-query context used for this Executor invocation.
112 * ----------------------------------------------------------------
115 ExecutorStart(QueryDesc *queryDesc, bool explainOnly)
118 MemoryContext oldcontext;
120 /* sanity checks: queryDesc must not be started already */
121 Assert(queryDesc != NULL);
122 Assert(queryDesc->estate == NULL);
125 * If the transaction is read-only, we need to check if any writes
126 * are planned to non-temporary tables.
129 ExecCheckXactReadOnly(queryDesc->parsetree, queryDesc->operation);
132 * Build EState, switch into per-query memory context for startup.
134 estate = CreateExecutorState();
135 queryDesc->estate = estate;
137 oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
140 * Fill in parameters, if any, from queryDesc
142 estate->es_param_list_info = queryDesc->params;
144 if (queryDesc->plantree->nParamExec > 0)
145 estate->es_param_exec_vals = (ParamExecData *)
146 palloc0(queryDesc->plantree->nParamExec * sizeof(ParamExecData));
148 estate->es_instrument = queryDesc->doInstrument;
151 * Make our own private copy of the current query snapshot data.
153 * This "freezes" our idea of which tuples are good and which are not for
154 * the life of this query, even if it outlives the current command and
157 estate->es_snapshot = CopyQuerySnapshot();
160 * Initialize the plan state tree
162 InitPlan(queryDesc, explainOnly);
164 MemoryContextSwitchTo(oldcontext);
167 /* ----------------------------------------------------------------
170 * This is the main routine of the executor module. It accepts
171 * the query descriptor from the traffic cop and executes the
174 * ExecutorStart must have been called already.
176 * If direction is NoMovementScanDirection then nothing is done
177 * except to start up/shut down the destination. Otherwise,
178 * we retrieve up to 'count' tuples in the specified direction.
180 * Note: count = 0 is interpreted as no portal limit, i.e., run to
183 * ----------------------------------------------------------------
186 ExecutorRun(QueryDesc *queryDesc,
187 ScanDirection direction, long count)
192 TupleTableSlot *result;
193 MemoryContext oldcontext;
196 Assert(queryDesc != NULL);
198 estate = queryDesc->estate;
200 Assert(estate != NULL);
203 * Switch into per-query memory context
205 oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
208 * extract information from the query descriptor and the query
211 operation = queryDesc->operation;
212 dest = queryDesc->dest;
215 * startup tuple receiver
217 estate->es_processed = 0;
218 estate->es_lastoid = InvalidOid;
220 (*dest->startup) (dest, operation, queryDesc->tupDesc);
225 if (direction == NoMovementScanDirection)
228 result = ExecutePlan(estate,
229 queryDesc->planstate,
238 (*dest->shutdown) (dest);
240 MemoryContextSwitchTo(oldcontext);
245 /* ----------------------------------------------------------------
248 * This routine must be called at the end of execution of any
250 * ----------------------------------------------------------------
253 ExecutorEnd(QueryDesc *queryDesc)
256 MemoryContext oldcontext;
259 Assert(queryDesc != NULL);
261 estate = queryDesc->estate;
263 Assert(estate != NULL);
266 * Switch into per-query memory context to run ExecEndPlan
268 oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
270 ExecEndPlan(queryDesc->planstate, estate);
273 * Must switch out of context before destroying it
275 MemoryContextSwitchTo(oldcontext);
278 * Release EState and per-query memory context. This should release
279 * everything the executor has allocated.
281 FreeExecutorState(estate);
283 /* Reset queryDesc fields that no longer point to anything */
284 queryDesc->tupDesc = NULL;
285 queryDesc->estate = NULL;
286 queryDesc->planstate = NULL;
289 /* ----------------------------------------------------------------
292 * This routine may be called on an open queryDesc to rewind it
294 * ----------------------------------------------------------------
297 ExecutorRewind(QueryDesc *queryDesc)
300 MemoryContext oldcontext;
303 Assert(queryDesc != NULL);
305 estate = queryDesc->estate;
307 Assert(estate != NULL);
309 /* It's probably not sensible to rescan updating queries */
310 Assert(queryDesc->operation == CMD_SELECT);
313 * Switch into per-query memory context
315 oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
320 ExecReScan(queryDesc->planstate, NULL);
322 MemoryContextSwitchTo(oldcontext);
328 * Check access permissions for all relations listed in a range table.
331 ExecCheckRTPerms(List *rangeTable, CmdType operation)
335 foreach(lp, rangeTable)
337 RangeTblEntry *rte = lfirst(lp);
339 ExecCheckRTEPerms(rte, operation);
345 * Check access permissions for a single RTE.
348 ExecCheckRTEPerms(RangeTblEntry *rte, CmdType operation)
352 AclResult aclcheck_result;
355 * If it's a subquery, recursively examine its rangetable.
357 if (rte->rtekind == RTE_SUBQUERY)
359 ExecCheckRTPerms(rte->subquery->rtable, operation);
364 * Otherwise, only plain-relation RTEs need to be checked here.
365 * Function RTEs are checked by init_fcache when the function is prepared
366 * for execution. Join and special RTEs need no checks.
368 if (rte->rtekind != RTE_RELATION)
374 * userid to check as: current user unless we have a setuid
377 * Note: GetUserId() is presently fast enough that there's no harm in
378 * calling it separately for each RTE. If that stops being true, we
379 * could call it once in ExecCheckRTPerms and pass the userid down
380 * from there. But for now, no need for the extra clutter.
382 userid = rte->checkAsUser ? rte->checkAsUser : GetUserId();
384 #define CHECK(MODE) pg_class_aclcheck(relOid, userid, MODE)
386 if (rte->checkForRead)
388 aclcheck_result = CHECK(ACL_SELECT);
389 if (aclcheck_result != ACLCHECK_OK)
390 aclcheck_error(aclcheck_result, get_rel_name(relOid));
393 if (rte->checkForWrite)
396 * Note: write access in a SELECT context means SELECT FOR UPDATE.
397 * Right now we don't distinguish that from true update as far as
398 * permissions checks are concerned.
403 aclcheck_result = CHECK(ACL_INSERT);
407 aclcheck_result = CHECK(ACL_UPDATE);
410 aclcheck_result = CHECK(ACL_DELETE);
413 elog(ERROR, "unrecognized operation code: %d",
415 aclcheck_result = ACLCHECK_OK; /* keep compiler quiet */
418 if (aclcheck_result != ACLCHECK_OK)
419 aclcheck_error(aclcheck_result, get_rel_name(relOid));
424 ExecCheckXactReadOnly(Query *parsetree, CmdType operation)
429 /* CREATE TABLE AS or SELECT INTO */
430 if (operation == CMD_SELECT && parsetree->into != NULL)
433 if (operation == CMD_DELETE || operation == CMD_INSERT
434 || operation == CMD_UPDATE)
438 foreach(lp, parsetree->rtable)
440 RangeTblEntry *rte = lfirst(lp);
442 if (rte->rtekind != RTE_RELATION)
445 if (!rte->checkForWrite)
448 if (isTempNamespace(get_rel_namespace(rte->relid)))
459 (errcode(ERRCODE_READ_ONLY_SQL_TRANSACTION),
460 errmsg("transaction is read-only")));
464 /* ----------------------------------------------------------------
467 * Initializes the query plan: open files, allocate storage
468 * and start up the rule manager
469 * ----------------------------------------------------------------
472 InitPlan(QueryDesc *queryDesc, bool explainOnly)
474 CmdType operation = queryDesc->operation;
475 Query *parseTree = queryDesc->parsetree;
476 Plan *plan = queryDesc->plantree;
477 EState *estate = queryDesc->estate;
478 PlanState *planstate;
480 Relation intoRelationDesc;
485 * Do permissions checks. It's sufficient to examine the query's
486 * top rangetable here --- subplan RTEs will be checked during
489 ExecCheckRTPerms(parseTree->rtable, operation);
492 * get information from query descriptor
494 rangeTable = parseTree->rtable;
497 * initialize the node's execution state
499 estate->es_range_table = rangeTable;
502 * if there is a result relation, initialize result relation stuff
504 if (parseTree->resultRelation != 0 && operation != CMD_SELECT)
506 List *resultRelations = parseTree->resultRelations;
507 int numResultRelations;
508 ResultRelInfo *resultRelInfos;
510 if (resultRelations != NIL)
513 * Multiple result relations (due to inheritance)
514 * parseTree->resultRelations identifies them all
516 ResultRelInfo *resultRelInfo;
518 numResultRelations = length(resultRelations);
519 resultRelInfos = (ResultRelInfo *)
520 palloc(numResultRelations * sizeof(ResultRelInfo));
521 resultRelInfo = resultRelInfos;
522 while (resultRelations != NIL)
524 initResultRelInfo(resultRelInfo,
525 lfirsti(resultRelations),
529 resultRelations = lnext(resultRelations);
535 * Single result relation identified by
536 * parseTree->resultRelation
538 numResultRelations = 1;
539 resultRelInfos = (ResultRelInfo *) palloc(sizeof(ResultRelInfo));
540 initResultRelInfo(resultRelInfos,
541 parseTree->resultRelation,
546 estate->es_result_relations = resultRelInfos;
547 estate->es_num_result_relations = numResultRelations;
548 /* Initialize to first or only result rel */
549 estate->es_result_relation_info = resultRelInfos;
554 * if no result relation, then set state appropriately
556 estate->es_result_relations = NULL;
557 estate->es_num_result_relations = 0;
558 estate->es_result_relation_info = NULL;
562 * Detect whether we're doing SELECT INTO. If so, set the force_oids
563 * flag appropriately so that the plan tree will be initialized with
564 * the correct tuple descriptors.
566 do_select_into = false;
568 if (operation == CMD_SELECT && parseTree->into != NULL)
570 do_select_into = true;
572 * For now, always create OIDs in SELECT INTO; this is for backwards
573 * compatibility with pre-7.3 behavior. Eventually we might want
574 * to allow the user to choose.
576 estate->es_force_oids = true;
580 * Have to lock relations selected for update
582 estate->es_rowMark = NIL;
583 if (parseTree->rowMarks != NIL)
587 foreach(l, parseTree->rowMarks)
589 Index rti = lfirsti(l);
590 Oid relid = getrelid(rti, rangeTable);
594 relation = heap_open(relid, RowShareLock);
595 erm = (execRowMark *) palloc(sizeof(execRowMark));
596 erm->relation = relation;
598 snprintf(erm->resname, sizeof(erm->resname), "ctid%u", rti);
599 estate->es_rowMark = lappend(estate->es_rowMark, erm);
604 * initialize the executor "tuple" table. We need slots for all the
605 * plan nodes, plus possibly output slots for the junkfilter(s). At
606 * this point we aren't sure if we need junkfilters, so just add slots
607 * for them unconditionally.
610 int nSlots = ExecCountSlotsNode(plan);
612 if (parseTree->resultRelations != NIL)
613 nSlots += length(parseTree->resultRelations);
616 estate->es_tupleTable = ExecCreateTupleTable(nSlots);
619 /* mark EvalPlanQual not active */
620 estate->es_topPlan = plan;
621 estate->es_evalPlanQual = NULL;
622 estate->es_evTupleNull = NULL;
623 estate->es_evTuple = NULL;
624 estate->es_useEvalPlan = false;
627 * initialize the private state information for all the nodes in the
628 * query tree. This opens files, allocates storage and leaves us
629 * ready to start processing tuples.
631 planstate = ExecInitNode(plan, estate);
634 * Get the tuple descriptor describing the type of tuples to return.
635 * (this is especially important if we are creating a relation with
638 tupType = ExecGetResultType(planstate);
641 * Initialize the junk filter if needed. SELECT and INSERT queries need a
642 * filter if there are any junk attrs in the tlist. INSERT and SELECT
643 * INTO also need a filter if the top plan node is a scan node that's not
644 * doing projection (else we'll be scribbling on the scan tuple!) UPDATE
645 * and DELETE always need a filter, since there's always a junk 'ctid'
646 * attribute present --- no need to look first.
649 bool junk_filter_needed = false;
656 foreach(tlist, plan->targetlist)
658 TargetEntry *tle = (TargetEntry *) lfirst(tlist);
660 if (tle->resdom->resjunk)
662 junk_filter_needed = true;
666 if (!junk_filter_needed &&
667 (operation == CMD_INSERT || do_select_into))
669 if (IsA(planstate, SeqScanState) ||
670 IsA(planstate, IndexScanState) ||
671 IsA(planstate, TidScanState) ||
672 IsA(planstate, SubqueryScanState) ||
673 IsA(planstate, FunctionScanState))
675 if (planstate->ps_ProjInfo == NULL)
676 junk_filter_needed = true;
682 junk_filter_needed = true;
688 if (junk_filter_needed)
691 * If there are multiple result relations, each one needs its
692 * own junk filter. Note this is only possible for
693 * UPDATE/DELETE, so we can't be fooled by some needing a
694 * filter and some not.
696 if (parseTree->resultRelations != NIL)
698 PlanState **appendplans;
700 ResultRelInfo *resultRelInfo;
703 /* Top plan had better be an Append here. */
704 Assert(IsA(plan, Append));
705 Assert(((Append *) plan)->isTarget);
706 Assert(IsA(planstate, AppendState));
707 appendplans = ((AppendState *) planstate)->appendplans;
708 as_nplans = ((AppendState *) planstate)->as_nplans;
709 Assert(as_nplans == estate->es_num_result_relations);
710 resultRelInfo = estate->es_result_relations;
711 for (i = 0; i < as_nplans; i++)
713 PlanState *subplan = appendplans[i];
716 j = ExecInitJunkFilter(subplan->plan->targetlist,
717 ExecGetResultType(subplan),
718 ExecAllocTableSlot(estate->es_tupleTable));
719 resultRelInfo->ri_junkFilter = j;
724 * Set active junkfilter too; at this point ExecInitAppend
725 * has already selected an active result relation...
727 estate->es_junkFilter =
728 estate->es_result_relation_info->ri_junkFilter;
732 /* Normal case with just one JunkFilter */
735 j = ExecInitJunkFilter(planstate->plan->targetlist,
737 ExecAllocTableSlot(estate->es_tupleTable));
738 estate->es_junkFilter = j;
739 if (estate->es_result_relation_info)
740 estate->es_result_relation_info->ri_junkFilter = j;
742 /* For SELECT, want to return the cleaned tuple type */
743 if (operation == CMD_SELECT)
744 tupType = j->jf_cleanTupType;
748 estate->es_junkFilter = NULL;
752 * If doing SELECT INTO, initialize the "into" relation. We must wait
753 * till now so we have the "clean" result tuple type to create the
756 * If EXPLAIN, skip creating the "into" relation.
758 intoRelationDesc = (Relation) NULL;
760 if (do_select_into && !explainOnly)
769 * find namespace to create in, check permissions
771 intoName = parseTree->into->relname;
772 namespaceId = RangeVarGetCreationNamespace(parseTree->into);
774 aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(),
776 if (aclresult != ACLCHECK_OK)
777 aclcheck_error(aclresult, get_namespace_name(namespaceId));
780 * have to copy tupType to get rid of constraints
782 tupdesc = CreateTupleDescCopy(tupType);
784 intoRelationId = heap_create_with_catalog(intoName,
790 allowSystemTableMods);
792 FreeTupleDesc(tupdesc);
795 * Advance command counter so that the newly-created
796 * relation's catalog tuples will be visible to heap_open.
798 CommandCounterIncrement();
801 * If necessary, create a TOAST table for the into
802 * relation. Note that AlterTableCreateToastTable ends
803 * with CommandCounterIncrement(), so that the TOAST table
804 * will be visible for insertion.
806 AlterTableCreateToastTable(intoRelationId, true);
809 * And open the constructed table for writing.
811 intoRelationDesc = heap_open(intoRelationId, AccessExclusiveLock);
814 estate->es_into_relation_descriptor = intoRelationDesc;
816 queryDesc->tupDesc = tupType;
817 queryDesc->planstate = planstate;
821 * Initialize ResultRelInfo data for one result relation
824 initResultRelInfo(ResultRelInfo *resultRelInfo,
825 Index resultRelationIndex,
829 Oid resultRelationOid;
830 Relation resultRelationDesc;
832 resultRelationOid = getrelid(resultRelationIndex, rangeTable);
833 resultRelationDesc = heap_open(resultRelationOid, RowExclusiveLock);
835 switch (resultRelationDesc->rd_rel->relkind)
837 case RELKIND_SEQUENCE:
839 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
840 errmsg("cannot change sequence relation \"%s\"",
841 RelationGetRelationName(resultRelationDesc))));
843 case RELKIND_TOASTVALUE:
845 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
846 errmsg("cannot change toast relation \"%s\"",
847 RelationGetRelationName(resultRelationDesc))));
851 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
852 errmsg("cannot change view relation \"%s\"",
853 RelationGetRelationName(resultRelationDesc))));
857 MemSet(resultRelInfo, 0, sizeof(ResultRelInfo));
858 resultRelInfo->type = T_ResultRelInfo;
859 resultRelInfo->ri_RangeTableIndex = resultRelationIndex;
860 resultRelInfo->ri_RelationDesc = resultRelationDesc;
861 resultRelInfo->ri_NumIndices = 0;
862 resultRelInfo->ri_IndexRelationDescs = NULL;
863 resultRelInfo->ri_IndexRelationInfo = NULL;
864 /* make a copy so as not to depend on relcache info not changing... */
865 resultRelInfo->ri_TrigDesc = CopyTriggerDesc(resultRelationDesc->trigdesc);
866 resultRelInfo->ri_TrigFunctions = NULL;
867 resultRelInfo->ri_ConstraintExprs = NULL;
868 resultRelInfo->ri_junkFilter = NULL;
871 * If there are indices on the result relation, open them and save
872 * descriptors in the result relation info, so that we can add new
873 * index entries for the tuples we add/update. We need not do this
874 * for a DELETE, however, since deletion doesn't affect indexes.
876 if (resultRelationDesc->rd_rel->relhasindex &&
877 operation != CMD_DELETE)
878 ExecOpenIndices(resultRelInfo);
881 /* ----------------------------------------------------------------
884 * Cleans up the query plan -- closes files and frees up storage
886 * NOTE: we are no longer very worried about freeing storage per se
887 * in this code; FreeExecutorState should be guaranteed to release all
888 * memory that needs to be released. What we are worried about doing
889 * is closing relations and dropping buffer pins. Thus, for example,
890 * tuple tables must be cleared or dropped to ensure pins are released.
891 * ----------------------------------------------------------------
894 ExecEndPlan(PlanState *planstate, EState *estate)
896 ResultRelInfo *resultRelInfo;
901 * shut down any PlanQual processing we were doing
903 if (estate->es_evalPlanQual != NULL)
904 EndEvalPlanQual(estate);
907 * shut down the node-type-specific query processing
909 ExecEndNode(planstate);
912 * destroy the executor "tuple" table.
914 ExecDropTupleTable(estate->es_tupleTable, true);
915 estate->es_tupleTable = NULL;
918 * close the result relation(s) if any, but hold locks until xact
921 resultRelInfo = estate->es_result_relations;
922 for (i = estate->es_num_result_relations; i > 0; i--)
924 /* Close indices and then the relation itself */
925 ExecCloseIndices(resultRelInfo);
926 heap_close(resultRelInfo->ri_RelationDesc, NoLock);
931 * close the "into" relation if necessary, again keeping lock
933 if (estate->es_into_relation_descriptor != NULL)
934 heap_close(estate->es_into_relation_descriptor, NoLock);
937 * close any relations selected FOR UPDATE, again keeping locks
939 foreach(l, estate->es_rowMark)
941 execRowMark *erm = lfirst(l);
943 heap_close(erm->relation, NoLock);
947 /* ----------------------------------------------------------------
950 * processes the query plan to retrieve 'numberTuples' tuples in the
951 * direction specified.
953 * Retrieves all tuples if numberTuples is 0
955 * result is either a slot containing the last tuple in the case
956 * of a SELECT or NULL otherwise.
958 * Note: the ctid attribute is a 'junk' attribute that is removed before the
960 * ----------------------------------------------------------------
962 static TupleTableSlot *
963 ExecutePlan(EState *estate,
964 PlanState *planstate,
967 ScanDirection direction,
970 JunkFilter *junkfilter;
971 TupleTableSlot *slot;
972 ItemPointer tupleid = NULL;
973 ItemPointerData tuple_ctid;
974 long current_tuple_count;
975 TupleTableSlot *result;
978 * initialize local variables
981 current_tuple_count = 0;
987 estate->es_direction = direction;
990 * Process BEFORE EACH STATEMENT triggers
995 ExecBSUpdateTriggers(estate, estate->es_result_relation_info);
998 ExecBSDeleteTriggers(estate, estate->es_result_relation_info);
1001 ExecBSInsertTriggers(estate, estate->es_result_relation_info);
1009 * Loop until we've processed the proper number of tuples from the
1015 /* Reset the per-output-tuple exprcontext */
1016 ResetPerTupleExprContext(estate);
1019 * Execute the plan and obtain a tuple
1022 if (estate->es_useEvalPlan)
1024 slot = EvalPlanQualNext(estate);
1025 if (TupIsNull(slot))
1026 slot = ExecProcNode(planstate);
1029 slot = ExecProcNode(planstate);
1032 * if the tuple is null, then we assume there is nothing more to
1033 * process so we just return null...
1035 if (TupIsNull(slot))
1042 * if we have a junk filter, then project a new tuple with the
1045 * Store this new "clean" tuple in the junkfilter's resultSlot.
1046 * (Formerly, we stored it back over the "dirty" tuple, which is
1047 * WRONG because that tuple slot has the wrong descriptor.)
1049 * Also, extract all the junk information we need.
1051 if ((junkfilter = estate->es_junkFilter) != (JunkFilter *) NULL)
1058 * extract the 'ctid' junk attribute.
1060 if (operation == CMD_UPDATE || operation == CMD_DELETE)
1062 if (!ExecGetJunkAttribute(junkfilter,
1067 elog(ERROR, "could not find junk ctid column");
1069 /* shouldn't ever get a null result... */
1071 elog(ERROR, "ctid is NULL");
1073 tupleid = (ItemPointer) DatumGetPointer(datum);
1074 tuple_ctid = *tupleid; /* make sure we don't free the
1076 tupleid = &tuple_ctid;
1078 else if (estate->es_rowMark != NIL)
1083 foreach(l, estate->es_rowMark)
1085 execRowMark *erm = lfirst(l);
1087 HeapTupleData tuple;
1088 TupleTableSlot *newSlot;
1091 if (!ExecGetJunkAttribute(junkfilter,
1096 elog(ERROR, "could not find junk \"%s\" column",
1099 /* shouldn't ever get a null result... */
1101 elog(ERROR, "\"%s\" is NULL", erm->resname);
1103 tuple.t_self = *((ItemPointer) DatumGetPointer(datum));
1104 test = heap_mark4update(erm->relation, &tuple, &buffer,
1105 estate->es_snapshot->curcid);
1106 ReleaseBuffer(buffer);
1109 case HeapTupleSelfUpdated:
1110 /* treat it as deleted; do not process */
1113 case HeapTupleMayBeUpdated:
1116 case HeapTupleUpdated:
1117 if (XactIsoLevel == XACT_SERIALIZABLE)
1119 (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
1120 errmsg("cannot serialize access due to concurrent update")));
1121 if (!(ItemPointerEquals(&(tuple.t_self),
1122 (ItemPointer) DatumGetPointer(datum))))
1124 newSlot = EvalPlanQual(estate, erm->rti, &(tuple.t_self));
1125 if (!(TupIsNull(newSlot)))
1128 estate->es_useEvalPlan = true;
1134 * if tuple was deleted or PlanQual failed for
1135 * updated tuple - we must not return this
1141 elog(ERROR, "unrecognized heap_mark4update status: %u",
1149 * Finally create a new "clean" tuple with all junk attributes
1152 newTuple = ExecRemoveJunk(junkfilter, slot);
1154 slot = ExecStoreTuple(newTuple, /* tuple to store */
1155 junkfilter->jf_resultSlot, /* dest slot */
1156 InvalidBuffer, /* this tuple has no
1158 true); /* tuple should be pfreed */
1162 * now that we have a tuple, do the appropriate thing with it..
1163 * either return it to the user, add it to a relation someplace,
1164 * delete it from a relation, or modify some of its attributes.
1169 ExecSelect(slot, /* slot containing tuple */
1170 dest, /* destination's tuple-receiver obj */
1176 ExecInsert(slot, tupleid, estate);
1181 ExecDelete(slot, tupleid, estate);
1186 ExecUpdate(slot, tupleid, estate);
1191 elog(ERROR, "unrecognized operation code: %d",
1198 * check our tuple count.. if we've processed the proper number
1199 * then quit, else loop again and process more tuples. Zero
1200 * numberTuples means no limit.
1202 current_tuple_count++;
1203 if (numberTuples && numberTuples == current_tuple_count)
1208 * Process AFTER EACH STATEMENT triggers
1213 ExecASUpdateTriggers(estate, estate->es_result_relation_info);
1216 ExecASDeleteTriggers(estate, estate->es_result_relation_info);
1219 ExecASInsertTriggers(estate, estate->es_result_relation_info);
1227 * here, result is either a slot containing a tuple in the case of a
1228 * SELECT or NULL otherwise.
1233 /* ----------------------------------------------------------------
1236 * SELECTs are easy.. we just pass the tuple to the appropriate
1237 * print function. The only complexity is when we do a
1238 * "SELECT INTO", in which case we insert the tuple into
1239 * the appropriate relation (note: this is a newly created relation
1240 * so we don't need to worry about indices or locks.)
1241 * ----------------------------------------------------------------
1244 ExecSelect(TupleTableSlot *slot,
1252 * get the heap tuple out of the tuple table slot
1255 attrtype = slot->ttc_tupleDescriptor;
1258 * insert the tuple into the "into relation"
1260 * XXX this probably ought to be replaced by a separate destination
1262 if (estate->es_into_relation_descriptor != NULL)
1264 heap_insert(estate->es_into_relation_descriptor, tuple,
1265 estate->es_snapshot->curcid);
1270 * send the tuple to the destination
1272 (*dest->receiveTuple) (tuple, attrtype, dest);
1274 (estate->es_processed)++;
1277 /* ----------------------------------------------------------------
1280 * INSERTs are trickier.. we have to insert the tuple into
1281 * the base relation and insert appropriate tuples into the
1283 * ----------------------------------------------------------------
1286 ExecInsert(TupleTableSlot *slot,
1287 ItemPointer tupleid,
1291 ResultRelInfo *resultRelInfo;
1292 Relation resultRelationDesc;
1297 * get the heap tuple out of the tuple table slot
1302 * get information on the (current) result relation
1304 resultRelInfo = estate->es_result_relation_info;
1305 resultRelationDesc = resultRelInfo->ri_RelationDesc;
1307 /* BEFORE ROW INSERT Triggers */
1308 if (resultRelInfo->ri_TrigDesc &&
1309 resultRelInfo->ri_TrigDesc->n_before_row[TRIGGER_EVENT_INSERT] > 0)
1313 newtuple = ExecBRInsertTriggers(estate, resultRelInfo, tuple);
1315 if (newtuple == NULL) /* "do nothing" */
1318 if (newtuple != tuple) /* modified by Trigger(s) */
1321 * Insert modified tuple into tuple table slot, replacing the
1322 * original. We assume that it was allocated in per-tuple
1323 * memory context, and therefore will go away by itself. The
1324 * tuple table slot should not try to clear it.
1326 ExecStoreTuple(newtuple, slot, InvalidBuffer, false);
1332 * Check the constraints of the tuple
1334 if (resultRelationDesc->rd_att->constr)
1335 ExecConstraints(resultRelInfo, slot, estate);
1340 newId = heap_insert(resultRelationDesc, tuple,
1341 estate->es_snapshot->curcid);
1344 (estate->es_processed)++;
1345 estate->es_lastoid = newId;
1346 setLastTid(&(tuple->t_self));
1351 * Note: heap_insert adds a new tuple to a relation. As a side effect,
1352 * the tupleid of the new tuple is placed in the new tuple's t_ctid
1355 numIndices = resultRelInfo->ri_NumIndices;
1357 ExecInsertIndexTuples(slot, &(tuple->t_self), estate, false);
1359 /* AFTER ROW INSERT Triggers */
1360 ExecARInsertTriggers(estate, resultRelInfo, tuple);
1363 /* ----------------------------------------------------------------
1366 * DELETE is like UPDATE, we delete the tuple and its
1368 * ----------------------------------------------------------------
1371 ExecDelete(TupleTableSlot *slot,
1372 ItemPointer tupleid,
1375 ResultRelInfo *resultRelInfo;
1376 Relation resultRelationDesc;
1377 ItemPointerData ctid;
1381 * get information on the (current) result relation
1383 resultRelInfo = estate->es_result_relation_info;
1384 resultRelationDesc = resultRelInfo->ri_RelationDesc;
1386 /* BEFORE ROW DELETE Triggers */
1387 if (resultRelInfo->ri_TrigDesc &&
1388 resultRelInfo->ri_TrigDesc->n_before_row[TRIGGER_EVENT_DELETE] > 0)
1392 dodelete = ExecBRDeleteTriggers(estate, resultRelInfo, tupleid,
1393 estate->es_snapshot->curcid);
1395 if (!dodelete) /* "do nothing" */
1403 result = heap_delete(resultRelationDesc, tupleid,
1405 estate->es_snapshot->curcid);
1408 case HeapTupleSelfUpdated:
1409 /* already deleted by self; nothing to do */
1412 case HeapTupleMayBeUpdated:
1415 case HeapTupleUpdated:
1416 if (XactIsoLevel == XACT_SERIALIZABLE)
1418 (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
1419 errmsg("cannot serialize access due to concurrent update")));
1420 else if (!(ItemPointerEquals(tupleid, &ctid)))
1422 TupleTableSlot *epqslot = EvalPlanQual(estate,
1423 resultRelInfo->ri_RangeTableIndex, &ctid);
1425 if (!TupIsNull(epqslot))
1431 /* tuple already deleted; nothing to do */
1435 elog(ERROR, "unrecognized heap_delete status: %u", result);
1440 (estate->es_processed)++;
1443 * Note: Normally one would think that we have to delete index tuples
1444 * associated with the heap tuple now..
1446 * ... but in POSTGRES, we have no need to do this because the vacuum
1447 * daemon automatically opens an index scan and deletes index tuples
1448 * when it finds deleted heap tuples. -cim 9/27/89
1451 /* AFTER ROW DELETE Triggers */
1452 ExecARDeleteTriggers(estate, resultRelInfo, tupleid);
1455 /* ----------------------------------------------------------------
1458 * note: we can't run UPDATE queries with transactions
1459 * off because UPDATEs are actually INSERTs and our
1460 * scan will mistakenly loop forever, updating the tuple
1461 * it just inserted.. This should be fixed but until it
1462 * is, we don't want to get stuck in an infinite loop
1463 * which corrupts your database..
1464 * ----------------------------------------------------------------
1467 ExecUpdate(TupleTableSlot *slot,
1468 ItemPointer tupleid,
1472 ResultRelInfo *resultRelInfo;
1473 Relation resultRelationDesc;
1474 ItemPointerData ctid;
1479 * abort the operation if not running transactions
1481 if (IsBootstrapProcessingMode())
1482 elog(ERROR, "cannot UPDATE during bootstrap");
1485 * get the heap tuple out of the tuple table slot
1490 * get information on the (current) result relation
1492 resultRelInfo = estate->es_result_relation_info;
1493 resultRelationDesc = resultRelInfo->ri_RelationDesc;
1495 /* BEFORE ROW UPDATE Triggers */
1496 if (resultRelInfo->ri_TrigDesc &&
1497 resultRelInfo->ri_TrigDesc->n_before_row[TRIGGER_EVENT_UPDATE] > 0)
1501 newtuple = ExecBRUpdateTriggers(estate, resultRelInfo,
1503 estate->es_snapshot->curcid);
1505 if (newtuple == NULL) /* "do nothing" */
1508 if (newtuple != tuple) /* modified by Trigger(s) */
1511 * Insert modified tuple into tuple table slot, replacing the
1512 * original. We assume that it was allocated in per-tuple
1513 * memory context, and therefore will go away by itself. The
1514 * tuple table slot should not try to clear it.
1516 ExecStoreTuple(newtuple, slot, InvalidBuffer, false);
1522 * Check the constraints of the tuple
1524 * If we generate a new candidate tuple after EvalPlanQual testing, we
1525 * must loop back here and recheck constraints. (We don't need to
1526 * redo triggers, however. If there are any BEFORE triggers then
1527 * trigger.c will have done mark4update to lock the correct tuple, so
1528 * there's no need to do them again.)
1531 if (resultRelationDesc->rd_att->constr)
1532 ExecConstraints(resultRelInfo, slot, estate);
1535 * replace the heap tuple
1537 result = heap_update(resultRelationDesc, tupleid, tuple,
1539 estate->es_snapshot->curcid);
1542 case HeapTupleSelfUpdated:
1543 /* already deleted by self; nothing to do */
1546 case HeapTupleMayBeUpdated:
1549 case HeapTupleUpdated:
1550 if (XactIsoLevel == XACT_SERIALIZABLE)
1552 (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
1553 errmsg("cannot serialize access due to concurrent update")));
1554 else if (!(ItemPointerEquals(tupleid, &ctid)))
1556 TupleTableSlot *epqslot = EvalPlanQual(estate,
1557 resultRelInfo->ri_RangeTableIndex, &ctid);
1559 if (!TupIsNull(epqslot))
1562 tuple = ExecRemoveJunk(estate->es_junkFilter, epqslot);
1563 slot = ExecStoreTuple(tuple,
1564 estate->es_junkFilter->jf_resultSlot,
1565 InvalidBuffer, true);
1569 /* tuple already deleted; nothing to do */
1573 elog(ERROR, "unrecognized heap_update status: %u", result);
1578 (estate->es_processed)++;
1581 * Note: instead of having to update the old index tuples associated
1582 * with the heap tuple, all we do is form and insert new index tuples.
1583 * This is because UPDATEs are actually DELETEs and INSERTs and index
1584 * tuple deletion is done automagically by the vacuum daemon. All we
1585 * do is insert new index tuples. -cim 9/27/89
1591 * heap_update updates a tuple in the base relation by invalidating it
1592 * and then inserting a new tuple to the relation. As a side effect,
1593 * the tupleid of the new tuple is placed in the new tuple's t_ctid
1594 * field. So we now insert index tuples using the new tupleid stored
1598 numIndices = resultRelInfo->ri_NumIndices;
1600 ExecInsertIndexTuples(slot, &(tuple->t_self), estate, false);
1602 /* AFTER ROW UPDATE Triggers */
1603 ExecARUpdateTriggers(estate, resultRelInfo, tupleid, tuple);
1607 ExecRelCheck(ResultRelInfo *resultRelInfo,
1608 TupleTableSlot *slot, EState *estate)
1610 Relation rel = resultRelInfo->ri_RelationDesc;
1611 int ncheck = rel->rd_att->constr->num_check;
1612 ConstrCheck *check = rel->rd_att->constr->check;
1613 ExprContext *econtext;
1614 MemoryContext oldContext;
1619 * If first time through for this result relation, build expression
1620 * nodetrees for rel's constraint expressions. Keep them in the
1621 * per-query memory context so they'll survive throughout the query.
1623 if (resultRelInfo->ri_ConstraintExprs == NULL)
1625 oldContext = MemoryContextSwitchTo(estate->es_query_cxt);
1626 resultRelInfo->ri_ConstraintExprs =
1627 (List **) palloc(ncheck * sizeof(List *));
1628 for (i = 0; i < ncheck; i++)
1630 qual = (List *) stringToNode(check[i].ccbin);
1631 resultRelInfo->ri_ConstraintExprs[i] = (List *)
1632 ExecPrepareExpr((Expr *) qual, estate);
1634 MemoryContextSwitchTo(oldContext);
1638 * We will use the EState's per-tuple context for evaluating
1639 * constraint expressions (creating it if it's not already there).
1641 econtext = GetPerTupleExprContext(estate);
1643 /* Arrange for econtext's scan tuple to be the tuple under test */
1644 econtext->ecxt_scantuple = slot;
1646 /* And evaluate the constraints */
1647 for (i = 0; i < ncheck; i++)
1649 qual = resultRelInfo->ri_ConstraintExprs[i];
1652 * NOTE: SQL92 specifies that a NULL result from a constraint
1653 * expression is not to be treated as a failure. Therefore, tell
1654 * ExecQual to return TRUE for NULL.
1656 if (!ExecQual(qual, econtext, true))
1657 return check[i].ccname;
1660 /* NULL result means no error */
1665 ExecConstraints(ResultRelInfo *resultRelInfo,
1666 TupleTableSlot *slot, EState *estate)
1668 Relation rel = resultRelInfo->ri_RelationDesc;
1669 HeapTuple tuple = slot->val;
1670 TupleConstr *constr = rel->rd_att->constr;
1674 if (constr->has_not_null)
1676 int natts = rel->rd_att->natts;
1679 for (attrChk = 1; attrChk <= natts; attrChk++)
1681 if (rel->rd_att->attrs[attrChk - 1]->attnotnull &&
1682 heap_attisnull(tuple, attrChk))
1684 (errcode(ERRCODE_NOT_NULL_VIOLATION),
1685 errmsg("null value for attribute \"%s\" violates NOT NULL constraint",
1686 NameStr(rel->rd_att->attrs[attrChk - 1]->attname))));
1690 if (constr->num_check > 0)
1694 if ((failed = ExecRelCheck(resultRelInfo, slot, estate)) != NULL)
1696 (errcode(ERRCODE_CHECK_VIOLATION),
1697 errmsg("new row for relation \"%s\" violates CHECK constraint \"%s\"",
1698 RelationGetRelationName(rel), failed)));
1703 * Check a modified tuple to see if we want to process its updated version
1704 * under READ COMMITTED rules.
1706 * See backend/executor/README for some info about how this works.
1709 EvalPlanQual(EState *estate, Index rti, ItemPointer tid)
1714 HeapTupleData tuple;
1715 HeapTuple copyTuple = NULL;
1721 * find relation containing target tuple
1723 if (estate->es_result_relation_info != NULL &&
1724 estate->es_result_relation_info->ri_RangeTableIndex == rti)
1725 relation = estate->es_result_relation_info->ri_RelationDesc;
1731 foreach(l, estate->es_rowMark)
1733 if (((execRowMark *) lfirst(l))->rti == rti)
1735 relation = ((execRowMark *) lfirst(l))->relation;
1739 if (relation == NULL)
1740 elog(ERROR, "cannot find RowMark for RT index %u", rti);
1746 * Loop here to deal with updated or busy tuples
1748 tuple.t_self = *tid;
1753 if (heap_fetch(relation, SnapshotDirty, &tuple, &buffer, false, NULL))
1755 TransactionId xwait = SnapshotDirty->xmax;
1757 /* xmin should not be dirty... */
1758 if (TransactionIdIsValid(SnapshotDirty->xmin))
1759 elog(ERROR, "t_xmin is uncommitted in tuple to be updated");
1762 * If tuple is being updated by other transaction then we have
1763 * to wait for its commit/abort.
1765 if (TransactionIdIsValid(xwait))
1767 ReleaseBuffer(buffer);
1768 XactLockTableWait(xwait);
1773 * We got tuple - now copy it for use by recheck query.
1775 copyTuple = heap_copytuple(&tuple);
1776 ReleaseBuffer(buffer);
1781 * Oops! Invalid tuple. Have to check is it updated or deleted.
1782 * Note that it's possible to get invalid SnapshotDirty->tid if
1783 * tuple updated by this transaction. Have we to check this ?
1785 if (ItemPointerIsValid(&(SnapshotDirty->tid)) &&
1786 !(ItemPointerEquals(&(tuple.t_self), &(SnapshotDirty->tid))))
1788 /* updated, so look at the updated copy */
1789 tuple.t_self = SnapshotDirty->tid;
1794 * Deleted or updated by this transaction; forget it.
1800 * For UPDATE/DELETE we have to return tid of actual row we're
1803 *tid = tuple.t_self;
1806 * Need to run a recheck subquery. Find or create a PQ stack entry.
1808 epq = estate->es_evalPlanQual;
1811 if (epq != NULL && epq->rti == 0)
1813 /* Top PQ stack entry is idle, so re-use it */
1814 Assert(!(estate->es_useEvalPlan) && epq->next == NULL);
1820 * If this is request for another RTE - Ra, - then we have to check
1821 * wasn't PlanQual requested for Ra already and if so then Ra' row was
1822 * updated again and we have to re-start old execution for Ra and
1823 * forget all what we done after Ra was suspended. Cool? -:))
1825 if (epq != NULL && epq->rti != rti &&
1826 epq->estate->es_evTuple[rti - 1] != NULL)
1830 evalPlanQual *oldepq;
1832 /* stop execution */
1833 EvalPlanQualStop(epq);
1834 /* pop previous PlanQual from the stack */
1836 Assert(oldepq && oldepq->rti != 0);
1837 /* push current PQ to freePQ stack */
1840 estate->es_evalPlanQual = epq;
1841 } while (epq->rti != rti);
1845 * If we are requested for another RTE then we have to suspend
1846 * execution of current PlanQual and start execution for new one.
1848 if (epq == NULL || epq->rti != rti)
1850 /* try to reuse plan used previously */
1851 evalPlanQual *newepq = (epq != NULL) ? epq->free : NULL;
1853 if (newepq == NULL) /* first call or freePQ stack is empty */
1855 newepq = (evalPlanQual *) palloc0(sizeof(evalPlanQual));
1856 newepq->free = NULL;
1857 newepq->estate = NULL;
1858 newepq->planstate = NULL;
1862 /* recycle previously used PlanQual */
1863 Assert(newepq->estate == NULL);
1866 /* push current PQ to the stack */
1869 estate->es_evalPlanQual = epq;
1874 Assert(epq->rti == rti);
1877 * Ok - we're requested for the same RTE. Unfortunately we still have
1878 * to end and restart execution of the plan, because ExecReScan
1879 * wouldn't ensure that upper plan nodes would reset themselves. We
1880 * could make that work if insertion of the target tuple were
1881 * integrated with the Param mechanism somehow, so that the upper plan
1882 * nodes know that their children's outputs have changed.
1884 * Note that the stack of free evalPlanQual nodes is quite useless at
1885 * the moment, since it only saves us from pallocing/releasing the
1886 * evalPlanQual nodes themselves. But it will be useful once we
1887 * implement ReScan instead of end/restart for re-using PlanQual nodes.
1891 /* stop execution */
1892 EvalPlanQualStop(epq);
1896 * Initialize new recheck query.
1898 * Note: if we were re-using PlanQual plans via ExecReScan, we'd need
1899 * to instead copy down changeable state from the top plan (including
1900 * es_result_relation_info, es_junkFilter) and reset locally changeable
1901 * state in the epq (including es_param_exec_vals, es_evTupleNull).
1903 EvalPlanQualStart(epq, estate, epq->next);
1906 * free old RTE' tuple, if any, and store target tuple where
1907 * relation's scan node will see it
1909 epqstate = epq->estate;
1910 if (epqstate->es_evTuple[rti - 1] != NULL)
1911 heap_freetuple(epqstate->es_evTuple[rti - 1]);
1912 epqstate->es_evTuple[rti - 1] = copyTuple;
1914 return EvalPlanQualNext(estate);
1917 static TupleTableSlot *
1918 EvalPlanQualNext(EState *estate)
1920 evalPlanQual *epq = estate->es_evalPlanQual;
1921 MemoryContext oldcontext;
1922 TupleTableSlot *slot;
1924 Assert(epq->rti != 0);
1927 oldcontext = MemoryContextSwitchTo(epq->estate->es_query_cxt);
1928 slot = ExecProcNode(epq->planstate);
1929 MemoryContextSwitchTo(oldcontext);
1932 * No more tuples for this PQ. Continue previous one.
1934 if (TupIsNull(slot))
1936 evalPlanQual *oldepq;
1938 /* stop execution */
1939 EvalPlanQualStop(epq);
1940 /* pop old PQ from the stack */
1944 /* this is the first (oldest) PQ - mark as free */
1946 estate->es_useEvalPlan = false;
1947 /* and continue Query execution */
1950 Assert(oldepq->rti != 0);
1951 /* push current PQ to freePQ stack */
1954 estate->es_evalPlanQual = epq;
1962 EndEvalPlanQual(EState *estate)
1964 evalPlanQual *epq = estate->es_evalPlanQual;
1966 if (epq->rti == 0) /* plans already shutdowned */
1968 Assert(epq->next == NULL);
1974 evalPlanQual *oldepq;
1976 /* stop execution */
1977 EvalPlanQualStop(epq);
1978 /* pop old PQ from the stack */
1982 /* this is the first (oldest) PQ - mark as free */
1984 estate->es_useEvalPlan = false;
1987 Assert(oldepq->rti != 0);
1988 /* push current PQ to freePQ stack */
1991 estate->es_evalPlanQual = epq;
1996 * Start execution of one level of PlanQual.
1998 * This is a cut-down version of ExecutorStart(): we copy some state from
1999 * the top-level estate rather than initializing it fresh.
2002 EvalPlanQualStart(evalPlanQual *epq, EState *estate, evalPlanQual *priorepq)
2006 MemoryContext oldcontext;
2008 rtsize = length(estate->es_range_table);
2010 epq->estate = epqstate = CreateExecutorState();
2012 oldcontext = MemoryContextSwitchTo(epqstate->es_query_cxt);
2015 * The epqstates share the top query's copy of unchanging state such
2016 * as the snapshot, rangetable, result-rel info, and external Param info.
2017 * They need their own copies of local state, including a tuple table,
2018 * es_param_exec_vals, etc.
2020 epqstate->es_direction = ForwardScanDirection;
2021 epqstate->es_snapshot = estate->es_snapshot;
2022 epqstate->es_range_table = estate->es_range_table;
2023 epqstate->es_result_relations = estate->es_result_relations;
2024 epqstate->es_num_result_relations = estate->es_num_result_relations;
2025 epqstate->es_result_relation_info = estate->es_result_relation_info;
2026 epqstate->es_junkFilter = estate->es_junkFilter;
2027 epqstate->es_into_relation_descriptor = estate->es_into_relation_descriptor;
2028 epqstate->es_param_list_info = estate->es_param_list_info;
2029 if (estate->es_topPlan->nParamExec > 0)
2030 epqstate->es_param_exec_vals = (ParamExecData *)
2031 palloc0(estate->es_topPlan->nParamExec * sizeof(ParamExecData));
2032 epqstate->es_rowMark = estate->es_rowMark;
2033 epqstate->es_instrument = estate->es_instrument;
2034 epqstate->es_force_oids = estate->es_force_oids;
2035 epqstate->es_topPlan = estate->es_topPlan;
2037 * Each epqstate must have its own es_evTupleNull state, but
2038 * all the stack entries share es_evTuple state. This allows
2039 * sub-rechecks to inherit the value being examined by an
2042 epqstate->es_evTupleNull = (bool *) palloc0(rtsize * sizeof(bool));
2043 if (priorepq == NULL)
2044 /* first PQ stack entry */
2045 epqstate->es_evTuple = (HeapTuple *)
2046 palloc0(rtsize * sizeof(HeapTuple));
2048 /* later stack entries share the same storage */
2049 epqstate->es_evTuple = priorepq->estate->es_evTuple;
2051 epqstate->es_tupleTable =
2052 ExecCreateTupleTable(estate->es_tupleTable->size);
2054 epq->planstate = ExecInitNode(estate->es_topPlan, epqstate);
2056 MemoryContextSwitchTo(oldcontext);
2060 * End execution of one level of PlanQual.
2062 * This is a cut-down version of ExecutorEnd(); basically we want to do most
2063 * of the normal cleanup, but *not* close result relations (which we are
2064 * just sharing from the outer query).
2067 EvalPlanQualStop(evalPlanQual *epq)
2069 EState *epqstate = epq->estate;
2070 MemoryContext oldcontext;
2072 oldcontext = MemoryContextSwitchTo(epqstate->es_query_cxt);
2074 ExecEndNode(epq->planstate);
2076 ExecDropTupleTable(epqstate->es_tupleTable, true);
2077 epqstate->es_tupleTable = NULL;
2079 if (epqstate->es_evTuple[epq->rti - 1] != NULL)
2081 heap_freetuple(epqstate->es_evTuple[epq->rti - 1]);
2082 epqstate->es_evTuple[epq->rti - 1] = NULL;
2085 MemoryContextSwitchTo(oldcontext);
2087 FreeExecutorState(epqstate);
2090 epq->planstate = NULL;