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11 * The old ExecutorMain() has been replaced by ExecutorStart(),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) 1996-2003, PostgreSQL Global Development Group
25 * Portions Copyright (c) 1994, Regents of the University of California
29 * $PostgreSQL: pgsql/src/backend/executor/execMain.c,v 1.225 2004/01/07 18:56:26 neilc 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/clauses.h"
44 #include "optimizer/var.h"
45 #include "parser/parsetree.h"
46 #include "utils/acl.h"
47 #include "utils/guc.h"
48 #include "utils/lsyscache.h"
51 typedef struct execRowMark
58 typedef struct evalPlanQual
63 struct evalPlanQual *next; /* stack of active PlanQual plans */
64 struct evalPlanQual *free; /* list of free PlanQual plans */
67 /* decls for local routines only used within this module */
68 static void InitPlan(QueryDesc *queryDesc, bool explainOnly);
69 static void initResultRelInfo(ResultRelInfo *resultRelInfo,
70 Index resultRelationIndex,
73 static TupleTableSlot *ExecutePlan(EState *estate, PlanState *planstate,
76 ScanDirection direction,
78 static void ExecSelect(TupleTableSlot *slot,
81 static void ExecInsert(TupleTableSlot *slot, ItemPointer tupleid,
83 static void ExecDelete(TupleTableSlot *slot, ItemPointer tupleid,
85 static void ExecUpdate(TupleTableSlot *slot, ItemPointer tupleid,
87 static TupleTableSlot *EvalPlanQualNext(EState *estate);
88 static void EndEvalPlanQual(EState *estate);
89 static void ExecCheckRTEPerms(RangeTblEntry *rte, CmdType operation);
90 static void ExecCheckXactReadOnly(Query *parsetree, CmdType operation);
91 static void EvalPlanQualStart(evalPlanQual *epq, EState *estate,
92 evalPlanQual *priorepq);
93 static void EvalPlanQualStop(evalPlanQual *epq);
95 /* end of local decls */
98 /* ----------------------------------------------------------------
101 * This routine must be called at the beginning of any execution of any
104 * Takes a QueryDesc previously created by CreateQueryDesc (it's not real
105 * clear why we bother to separate the two functions, but...). The tupDesc
106 * field of the QueryDesc is filled in to describe the tuples that will be
107 * returned, and the internal fields (estate and planstate) are set up.
109 * If useCurrentSnapshot is true, run the query with the latest available
110 * snapshot, instead of the normal QuerySnapshot. Also, if it's an update
111 * or delete query, check that the rows to be updated or deleted would be
112 * visible to the normal QuerySnapshot. (This is a special-case behavior
113 * needed for referential integrity updates in serializable transactions.
114 * We must check all currently-committed rows, but we want to throw a
115 * can't-serialize error if any rows that would need updates would not be
116 * visible under the normal serializable snapshot.)
118 * If explainOnly is true, we are not actually intending to run the plan,
119 * only to set up for EXPLAIN; so skip unwanted side-effects.
121 * NB: the CurrentMemoryContext when this is called will become the parent
122 * of the per-query context used for this Executor invocation.
123 * ----------------------------------------------------------------
126 ExecutorStart(QueryDesc *queryDesc, bool useCurrentSnapshot, bool explainOnly)
129 MemoryContext oldcontext;
131 /* sanity checks: queryDesc must not be started already */
132 Assert(queryDesc != NULL);
133 Assert(queryDesc->estate == NULL);
136 * If the transaction is read-only, we need to check if any writes are
137 * planned to non-temporary tables.
140 ExecCheckXactReadOnly(queryDesc->parsetree, queryDesc->operation);
143 * Build EState, switch into per-query memory context for startup.
145 estate = CreateExecutorState();
146 queryDesc->estate = estate;
148 oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
151 * Fill in parameters, if any, from queryDesc
153 estate->es_param_list_info = queryDesc->params;
155 if (queryDesc->plantree->nParamExec > 0)
156 estate->es_param_exec_vals = (ParamExecData *)
157 palloc0(queryDesc->plantree->nParamExec * sizeof(ParamExecData));
159 estate->es_instrument = queryDesc->doInstrument;
162 * Make our own private copy of the current query snapshot data.
164 * This "freezes" our idea of which tuples are good and which are not for
165 * the life of this query, even if it outlives the current command and
168 if (useCurrentSnapshot)
170 /* RI update/delete query --- must use an up-to-date snapshot */
171 estate->es_snapshot = CopyCurrentSnapshot();
172 /* crosscheck updates/deletes against transaction snapshot */
173 estate->es_crosscheck_snapshot = CopyQuerySnapshot();
177 /* normal query --- use query snapshot, no crosscheck */
178 estate->es_snapshot = CopyQuerySnapshot();
179 estate->es_crosscheck_snapshot = SnapshotAny;
183 * Initialize the plan state tree
185 InitPlan(queryDesc, explainOnly);
187 MemoryContextSwitchTo(oldcontext);
190 /* ----------------------------------------------------------------
193 * This is the main routine of the executor module. It accepts
194 * the query descriptor from the traffic cop and executes the
197 * ExecutorStart must have been called already.
199 * If direction is NoMovementScanDirection then nothing is done
200 * except to start up/shut down the destination. Otherwise,
201 * we retrieve up to 'count' tuples in the specified direction.
203 * Note: count = 0 is interpreted as no portal limit, i.e., run to
206 * ----------------------------------------------------------------
209 ExecutorRun(QueryDesc *queryDesc,
210 ScanDirection direction, long count)
215 TupleTableSlot *result;
216 MemoryContext oldcontext;
219 Assert(queryDesc != NULL);
221 estate = queryDesc->estate;
223 Assert(estate != NULL);
226 * Switch into per-query memory context
228 oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
231 * extract information from the query descriptor and the query
234 operation = queryDesc->operation;
235 dest = queryDesc->dest;
238 * startup tuple receiver
240 estate->es_processed = 0;
241 estate->es_lastoid = InvalidOid;
243 (*dest->rStartup) (dest, operation, queryDesc->tupDesc);
248 if (direction == NoMovementScanDirection)
251 result = ExecutePlan(estate,
252 queryDesc->planstate,
261 (*dest->rShutdown) (dest);
263 MemoryContextSwitchTo(oldcontext);
268 /* ----------------------------------------------------------------
271 * This routine must be called at the end of execution of any
273 * ----------------------------------------------------------------
276 ExecutorEnd(QueryDesc *queryDesc)
279 MemoryContext oldcontext;
282 Assert(queryDesc != NULL);
284 estate = queryDesc->estate;
286 Assert(estate != NULL);
289 * Switch into per-query memory context to run ExecEndPlan
291 oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
293 ExecEndPlan(queryDesc->planstate, estate);
296 * Must switch out of context before destroying it
298 MemoryContextSwitchTo(oldcontext);
301 * Release EState and per-query memory context. This should release
302 * everything the executor has allocated.
304 FreeExecutorState(estate);
306 /* Reset queryDesc fields that no longer point to anything */
307 queryDesc->tupDesc = NULL;
308 queryDesc->estate = NULL;
309 queryDesc->planstate = NULL;
312 /* ----------------------------------------------------------------
315 * This routine may be called on an open queryDesc to rewind it
317 * ----------------------------------------------------------------
320 ExecutorRewind(QueryDesc *queryDesc)
323 MemoryContext oldcontext;
326 Assert(queryDesc != NULL);
328 estate = queryDesc->estate;
330 Assert(estate != NULL);
332 /* It's probably not sensible to rescan updating queries */
333 Assert(queryDesc->operation == CMD_SELECT);
336 * Switch into per-query memory context
338 oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
343 ExecReScan(queryDesc->planstate, NULL);
345 MemoryContextSwitchTo(oldcontext);
351 * Check access permissions for all relations listed in a range table.
354 ExecCheckRTPerms(List *rangeTable, CmdType operation)
358 foreach(lp, rangeTable)
360 RangeTblEntry *rte = lfirst(lp);
362 ExecCheckRTEPerms(rte, operation);
368 * Check access permissions for a single RTE.
371 ExecCheckRTEPerms(RangeTblEntry *rte, CmdType operation)
375 AclResult aclcheck_result;
378 * If it's a subquery, recursively examine its rangetable.
380 if (rte->rtekind == RTE_SUBQUERY)
382 ExecCheckRTPerms(rte->subquery->rtable, operation);
387 * Otherwise, only plain-relation RTEs need to be checked here.
388 * Function RTEs are checked by init_fcache when the function is
389 * prepared for execution. Join and special RTEs need no checks.
391 if (rte->rtekind != RTE_RELATION)
397 * userid to check as: current user unless we have a setuid
400 * Note: GetUserId() is presently fast enough that there's no harm in
401 * calling it separately for each RTE. If that stops being true, we
402 * could call it once in ExecCheckRTPerms and pass the userid down
403 * from there. But for now, no need for the extra clutter.
405 userid = rte->checkAsUser ? rte->checkAsUser : GetUserId();
407 #define CHECK(MODE) pg_class_aclcheck(relOid, userid, MODE)
409 if (rte->checkForRead)
411 aclcheck_result = CHECK(ACL_SELECT);
412 if (aclcheck_result != ACLCHECK_OK)
413 aclcheck_error(aclcheck_result, ACL_KIND_CLASS,
414 get_rel_name(relOid));
417 if (rte->checkForWrite)
420 * Note: write access in a SELECT context means SELECT FOR UPDATE.
421 * Right now we don't distinguish that from true update as far as
422 * permissions checks are concerned.
427 aclcheck_result = CHECK(ACL_INSERT);
431 aclcheck_result = CHECK(ACL_UPDATE);
434 aclcheck_result = CHECK(ACL_DELETE);
437 elog(ERROR, "unrecognized operation code: %d",
439 aclcheck_result = ACLCHECK_OK; /* keep compiler quiet */
442 if (aclcheck_result != ACLCHECK_OK)
443 aclcheck_error(aclcheck_result, ACL_KIND_CLASS,
444 get_rel_name(relOid));
449 ExecCheckXactReadOnly(Query *parsetree, CmdType operation)
454 /* CREATE TABLE AS or SELECT INTO */
455 if (operation == CMD_SELECT && parsetree->into != NULL)
458 if (operation == CMD_DELETE || operation == CMD_INSERT
459 || operation == CMD_UPDATE)
463 foreach(lp, parsetree->rtable)
465 RangeTblEntry *rte = lfirst(lp);
467 if (rte->rtekind != RTE_RELATION)
470 if (!rte->checkForWrite)
473 if (isTempNamespace(get_rel_namespace(rte->relid)))
484 (errcode(ERRCODE_READ_ONLY_SQL_TRANSACTION),
485 errmsg("transaction is read-only")));
489 /* ----------------------------------------------------------------
492 * Initializes the query plan: open files, allocate storage
493 * and start up the rule manager
494 * ----------------------------------------------------------------
497 InitPlan(QueryDesc *queryDesc, bool explainOnly)
499 CmdType operation = queryDesc->operation;
500 Query *parseTree = queryDesc->parsetree;
501 Plan *plan = queryDesc->plantree;
502 EState *estate = queryDesc->estate;
503 PlanState *planstate;
505 Relation intoRelationDesc;
510 * Do permissions checks. It's sufficient to examine the query's top
511 * rangetable here --- subplan RTEs will be checked during
514 ExecCheckRTPerms(parseTree->rtable, operation);
517 * get information from query descriptor
519 rangeTable = parseTree->rtable;
522 * initialize the node's execution state
524 estate->es_range_table = rangeTable;
527 * if there is a result relation, initialize result relation stuff
529 if (parseTree->resultRelation != 0 && operation != CMD_SELECT)
531 List *resultRelations = parseTree->resultRelations;
532 int numResultRelations;
533 ResultRelInfo *resultRelInfos;
535 if (resultRelations != NIL)
538 * Multiple result relations (due to inheritance)
539 * parseTree->resultRelations identifies them all
541 ResultRelInfo *resultRelInfo;
543 numResultRelations = length(resultRelations);
544 resultRelInfos = (ResultRelInfo *)
545 palloc(numResultRelations * sizeof(ResultRelInfo));
546 resultRelInfo = resultRelInfos;
547 while (resultRelations != NIL)
549 initResultRelInfo(resultRelInfo,
550 lfirsti(resultRelations),
554 resultRelations = lnext(resultRelations);
560 * Single result relation identified by
561 * parseTree->resultRelation
563 numResultRelations = 1;
564 resultRelInfos = (ResultRelInfo *) palloc(sizeof(ResultRelInfo));
565 initResultRelInfo(resultRelInfos,
566 parseTree->resultRelation,
571 estate->es_result_relations = resultRelInfos;
572 estate->es_num_result_relations = numResultRelations;
573 /* Initialize to first or only result rel */
574 estate->es_result_relation_info = resultRelInfos;
579 * if no result relation, then set state appropriately
581 estate->es_result_relations = NULL;
582 estate->es_num_result_relations = 0;
583 estate->es_result_relation_info = NULL;
587 * Detect whether we're doing SELECT INTO. If so, set the force_oids
588 * flag appropriately so that the plan tree will be initialized with
589 * the correct tuple descriptors.
591 do_select_into = false;
593 if (operation == CMD_SELECT && parseTree->into != NULL)
595 do_select_into = true;
598 * The presence of OIDs in the result set of SELECT INTO is
599 * controlled by the default_with_oids GUC parameter. The
600 * behavior in versions of PostgreSQL prior to 7.5 is to
601 * always include OIDs.
603 estate->es_force_oids = default_with_oids;
607 * Have to lock relations selected for update
609 estate->es_rowMark = NIL;
610 if (parseTree->rowMarks != NIL)
614 foreach(l, parseTree->rowMarks)
616 Index rti = lfirsti(l);
617 Oid relid = getrelid(rti, rangeTable);
621 relation = heap_open(relid, RowShareLock);
622 erm = (execRowMark *) palloc(sizeof(execRowMark));
623 erm->relation = relation;
625 snprintf(erm->resname, sizeof(erm->resname), "ctid%u", rti);
626 estate->es_rowMark = lappend(estate->es_rowMark, erm);
631 * initialize the executor "tuple" table. We need slots for all the
632 * plan nodes, plus possibly output slots for the junkfilter(s). At
633 * this point we aren't sure if we need junkfilters, so just add slots
634 * for them unconditionally.
637 int nSlots = ExecCountSlotsNode(plan);
639 if (parseTree->resultRelations != NIL)
640 nSlots += length(parseTree->resultRelations);
643 estate->es_tupleTable = ExecCreateTupleTable(nSlots);
646 /* mark EvalPlanQual not active */
647 estate->es_topPlan = plan;
648 estate->es_evalPlanQual = NULL;
649 estate->es_evTupleNull = NULL;
650 estate->es_evTuple = NULL;
651 estate->es_useEvalPlan = false;
654 * initialize the private state information for all the nodes in the
655 * query tree. This opens files, allocates storage and leaves us
656 * ready to start processing tuples.
658 planstate = ExecInitNode(plan, estate);
661 * Get the tuple descriptor describing the type of tuples to return.
662 * (this is especially important if we are creating a relation with
665 tupType = ExecGetResultType(planstate);
668 * Initialize the junk filter if needed. SELECT and INSERT queries
669 * need a filter if there are any junk attrs in the tlist. INSERT and
670 * SELECT INTO also need a filter if the top plan node is a scan node
671 * that's not doing projection (else we'll be scribbling on the scan
672 * tuple!) UPDATE and DELETE always need a filter, since there's
673 * always a junk 'ctid' attribute present --- no need to look first.
676 bool junk_filter_needed = false;
683 foreach(tlist, plan->targetlist)
685 TargetEntry *tle = (TargetEntry *) lfirst(tlist);
687 if (tle->resdom->resjunk)
689 junk_filter_needed = true;
693 if (!junk_filter_needed &&
694 (operation == CMD_INSERT || do_select_into))
696 if (IsA(planstate, SeqScanState) ||
697 IsA(planstate, IndexScanState) ||
698 IsA(planstate, TidScanState) ||
699 IsA(planstate, SubqueryScanState) ||
700 IsA(planstate, FunctionScanState))
702 if (planstate->ps_ProjInfo == NULL)
703 junk_filter_needed = true;
709 junk_filter_needed = true;
715 if (junk_filter_needed)
718 * If there are multiple result relations, each one needs its
719 * own junk filter. Note this is only possible for
720 * UPDATE/DELETE, so we can't be fooled by some needing a
721 * filter and some not.
723 if (parseTree->resultRelations != NIL)
725 PlanState **appendplans;
727 ResultRelInfo *resultRelInfo;
730 /* Top plan had better be an Append here. */
731 Assert(IsA(plan, Append));
732 Assert(((Append *) plan)->isTarget);
733 Assert(IsA(planstate, AppendState));
734 appendplans = ((AppendState *) planstate)->appendplans;
735 as_nplans = ((AppendState *) planstate)->as_nplans;
736 Assert(as_nplans == estate->es_num_result_relations);
737 resultRelInfo = estate->es_result_relations;
738 for (i = 0; i < as_nplans; i++)
740 PlanState *subplan = appendplans[i];
743 j = ExecInitJunkFilter(subplan->plan->targetlist,
744 ExecGetResultType(subplan),
745 ExecAllocTableSlot(estate->es_tupleTable));
746 resultRelInfo->ri_junkFilter = j;
751 * Set active junkfilter too; at this point ExecInitAppend
752 * has already selected an active result relation...
754 estate->es_junkFilter =
755 estate->es_result_relation_info->ri_junkFilter;
759 /* Normal case with just one JunkFilter */
762 j = ExecInitJunkFilter(planstate->plan->targetlist,
764 ExecAllocTableSlot(estate->es_tupleTable));
765 estate->es_junkFilter = j;
766 if (estate->es_result_relation_info)
767 estate->es_result_relation_info->ri_junkFilter = j;
769 /* For SELECT, want to return the cleaned tuple type */
770 if (operation == CMD_SELECT)
771 tupType = j->jf_cleanTupType;
775 estate->es_junkFilter = NULL;
779 * If doing SELECT INTO, initialize the "into" relation. We must wait
780 * till now so we have the "clean" result tuple type to create the new
783 * If EXPLAIN, skip creating the "into" relation.
785 intoRelationDesc = NULL;
787 if (do_select_into && !explainOnly)
796 * find namespace to create in, check permissions
798 intoName = parseTree->into->relname;
799 namespaceId = RangeVarGetCreationNamespace(parseTree->into);
801 aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(),
803 if (aclresult != ACLCHECK_OK)
804 aclcheck_error(aclresult, ACL_KIND_NAMESPACE,
805 get_namespace_name(namespaceId));
808 * have to copy tupType to get rid of constraints
810 tupdesc = CreateTupleDescCopy(tupType);
812 intoRelationId = heap_create_with_catalog(intoName,
818 allowSystemTableMods);
820 FreeTupleDesc(tupdesc);
823 * Advance command counter so that the newly-created relation's
824 * catalog tuples will be visible to heap_open.
826 CommandCounterIncrement();
829 * If necessary, create a TOAST table for the into relation. Note
830 * that AlterTableCreateToastTable ends with
831 * CommandCounterIncrement(), so that the TOAST table will be
832 * visible for insertion.
834 AlterTableCreateToastTable(intoRelationId, true);
837 * And open the constructed table for writing.
839 intoRelationDesc = heap_open(intoRelationId, AccessExclusiveLock);
842 estate->es_into_relation_descriptor = intoRelationDesc;
844 queryDesc->tupDesc = tupType;
845 queryDesc->planstate = planstate;
849 * Initialize ResultRelInfo data for one result relation
852 initResultRelInfo(ResultRelInfo *resultRelInfo,
853 Index resultRelationIndex,
857 Oid resultRelationOid;
858 Relation resultRelationDesc;
860 resultRelationOid = getrelid(resultRelationIndex, rangeTable);
861 resultRelationDesc = heap_open(resultRelationOid, RowExclusiveLock);
863 switch (resultRelationDesc->rd_rel->relkind)
865 case RELKIND_SEQUENCE:
867 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
868 errmsg("cannot change sequence \"%s\"",
869 RelationGetRelationName(resultRelationDesc))));
871 case RELKIND_TOASTVALUE:
873 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
874 errmsg("cannot change TOAST relation \"%s\"",
875 RelationGetRelationName(resultRelationDesc))));
879 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
880 errmsg("cannot change view \"%s\"",
881 RelationGetRelationName(resultRelationDesc))));
885 MemSet(resultRelInfo, 0, sizeof(ResultRelInfo));
886 resultRelInfo->type = T_ResultRelInfo;
887 resultRelInfo->ri_RangeTableIndex = resultRelationIndex;
888 resultRelInfo->ri_RelationDesc = resultRelationDesc;
889 resultRelInfo->ri_NumIndices = 0;
890 resultRelInfo->ri_IndexRelationDescs = NULL;
891 resultRelInfo->ri_IndexRelationInfo = NULL;
892 /* make a copy so as not to depend on relcache info not changing... */
893 resultRelInfo->ri_TrigDesc = CopyTriggerDesc(resultRelationDesc->trigdesc);
894 resultRelInfo->ri_TrigFunctions = NULL;
895 resultRelInfo->ri_ConstraintExprs = NULL;
896 resultRelInfo->ri_junkFilter = NULL;
899 * If there are indices on the result relation, open them and save
900 * descriptors in the result relation info, so that we can add new
901 * index entries for the tuples we add/update. We need not do this
902 * for a DELETE, however, since deletion doesn't affect indexes.
904 if (resultRelationDesc->rd_rel->relhasindex &&
905 operation != CMD_DELETE)
906 ExecOpenIndices(resultRelInfo);
909 /* ----------------------------------------------------------------
912 * Cleans up the query plan -- closes files and frees up storage
914 * NOTE: we are no longer very worried about freeing storage per se
915 * in this code; FreeExecutorState should be guaranteed to release all
916 * memory that needs to be released. What we are worried about doing
917 * is closing relations and dropping buffer pins. Thus, for example,
918 * tuple tables must be cleared or dropped to ensure pins are released.
919 * ----------------------------------------------------------------
922 ExecEndPlan(PlanState *planstate, EState *estate)
924 ResultRelInfo *resultRelInfo;
929 * shut down any PlanQual processing we were doing
931 if (estate->es_evalPlanQual != NULL)
932 EndEvalPlanQual(estate);
935 * shut down the node-type-specific query processing
937 ExecEndNode(planstate);
940 * destroy the executor "tuple" table.
942 ExecDropTupleTable(estate->es_tupleTable, true);
943 estate->es_tupleTable = NULL;
946 * close the result relation(s) if any, but hold locks until xact
949 resultRelInfo = estate->es_result_relations;
950 for (i = estate->es_num_result_relations; i > 0; i--)
952 /* Close indices and then the relation itself */
953 ExecCloseIndices(resultRelInfo);
954 heap_close(resultRelInfo->ri_RelationDesc, NoLock);
959 * close the "into" relation if necessary, again keeping lock
961 if (estate->es_into_relation_descriptor != NULL)
962 heap_close(estate->es_into_relation_descriptor, NoLock);
965 * close any relations selected FOR UPDATE, again keeping locks
967 foreach(l, estate->es_rowMark)
969 execRowMark *erm = lfirst(l);
971 heap_close(erm->relation, NoLock);
975 /* ----------------------------------------------------------------
978 * processes the query plan to retrieve 'numberTuples' tuples in the
979 * direction specified.
981 * Retrieves all tuples if numberTuples is 0
983 * result is either a slot containing the last tuple in the case
984 * of a SELECT or NULL otherwise.
986 * Note: the ctid attribute is a 'junk' attribute that is removed before the
988 * ----------------------------------------------------------------
990 static TupleTableSlot *
991 ExecutePlan(EState *estate,
992 PlanState *planstate,
995 ScanDirection direction,
998 JunkFilter *junkfilter;
999 TupleTableSlot *slot;
1000 ItemPointer tupleid = NULL;
1001 ItemPointerData tuple_ctid;
1002 long current_tuple_count;
1003 TupleTableSlot *result;
1006 * initialize local variables
1009 current_tuple_count = 0;
1013 * Set the direction.
1015 estate->es_direction = direction;
1018 * Process BEFORE EACH STATEMENT triggers
1023 ExecBSUpdateTriggers(estate, estate->es_result_relation_info);
1026 ExecBSDeleteTriggers(estate, estate->es_result_relation_info);
1029 ExecBSInsertTriggers(estate, estate->es_result_relation_info);
1037 * Loop until we've processed the proper number of tuples from the
1043 /* Reset the per-output-tuple exprcontext */
1044 ResetPerTupleExprContext(estate);
1047 * Execute the plan and obtain a tuple
1050 if (estate->es_useEvalPlan)
1052 slot = EvalPlanQualNext(estate);
1053 if (TupIsNull(slot))
1054 slot = ExecProcNode(planstate);
1057 slot = ExecProcNode(planstate);
1060 * if the tuple is null, then we assume there is nothing more to
1061 * process so we just return null...
1063 if (TupIsNull(slot))
1070 * if we have a junk filter, then project a new tuple with the
1073 * Store this new "clean" tuple in the junkfilter's resultSlot.
1074 * (Formerly, we stored it back over the "dirty" tuple, which is
1075 * WRONG because that tuple slot has the wrong descriptor.)
1077 * Also, extract all the junk information we need.
1079 if ((junkfilter = estate->es_junkFilter) != NULL)
1086 * extract the 'ctid' junk attribute.
1088 if (operation == CMD_UPDATE || operation == CMD_DELETE)
1090 if (!ExecGetJunkAttribute(junkfilter,
1095 elog(ERROR, "could not find junk ctid column");
1097 /* shouldn't ever get a null result... */
1099 elog(ERROR, "ctid is NULL");
1101 tupleid = (ItemPointer) DatumGetPointer(datum);
1102 tuple_ctid = *tupleid; /* make sure we don't free the
1104 tupleid = &tuple_ctid;
1106 else if (estate->es_rowMark != NIL)
1111 foreach(l, estate->es_rowMark)
1113 execRowMark *erm = lfirst(l);
1115 HeapTupleData tuple;
1116 TupleTableSlot *newSlot;
1119 if (!ExecGetJunkAttribute(junkfilter,
1124 elog(ERROR, "could not find junk \"%s\" column",
1127 /* shouldn't ever get a null result... */
1129 elog(ERROR, "\"%s\" is NULL", erm->resname);
1131 tuple.t_self = *((ItemPointer) DatumGetPointer(datum));
1132 test = heap_mark4update(erm->relation, &tuple, &buffer,
1133 estate->es_snapshot->curcid);
1134 ReleaseBuffer(buffer);
1137 case HeapTupleSelfUpdated:
1138 /* treat it as deleted; do not process */
1141 case HeapTupleMayBeUpdated:
1144 case HeapTupleUpdated:
1145 if (IsXactIsoLevelSerializable)
1147 (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
1148 errmsg("could not serialize access due to concurrent update")));
1149 if (!(ItemPointerEquals(&(tuple.t_self),
1150 (ItemPointer) DatumGetPointer(datum))))
1152 newSlot = EvalPlanQual(estate, erm->rti, &(tuple.t_self));
1153 if (!(TupIsNull(newSlot)))
1156 estate->es_useEvalPlan = true;
1162 * if tuple was deleted or PlanQual failed for
1163 * updated tuple - we must not return this
1169 elog(ERROR, "unrecognized heap_mark4update status: %u",
1177 * Finally create a new "clean" tuple with all junk attributes
1180 newTuple = ExecRemoveJunk(junkfilter, slot);
1182 slot = ExecStoreTuple(newTuple, /* tuple to store */
1183 junkfilter->jf_resultSlot, /* dest slot */
1184 InvalidBuffer, /* this tuple has no
1186 true); /* tuple should be pfreed */
1190 * now that we have a tuple, do the appropriate thing with it..
1191 * either return it to the user, add it to a relation someplace,
1192 * delete it from a relation, or modify some of its attributes.
1197 ExecSelect(slot, /* slot containing tuple */
1198 dest, /* destination's tuple-receiver obj */
1204 ExecInsert(slot, tupleid, estate);
1209 ExecDelete(slot, tupleid, estate);
1214 ExecUpdate(slot, tupleid, estate);
1219 elog(ERROR, "unrecognized operation code: %d",
1226 * check our tuple count.. if we've processed the proper number
1227 * then quit, else loop again and process more tuples. Zero
1228 * numberTuples means no limit.
1230 current_tuple_count++;
1231 if (numberTuples && numberTuples == current_tuple_count)
1236 * Process AFTER EACH STATEMENT triggers
1241 ExecASUpdateTriggers(estate, estate->es_result_relation_info);
1244 ExecASDeleteTriggers(estate, estate->es_result_relation_info);
1247 ExecASInsertTriggers(estate, estate->es_result_relation_info);
1255 * here, result is either a slot containing a tuple in the case of a
1256 * SELECT or NULL otherwise.
1261 /* ----------------------------------------------------------------
1264 * SELECTs are easy.. we just pass the tuple to the appropriate
1265 * print function. The only complexity is when we do a
1266 * "SELECT INTO", in which case we insert the tuple into
1267 * the appropriate relation (note: this is a newly created relation
1268 * so we don't need to worry about indices or locks.)
1269 * ----------------------------------------------------------------
1272 ExecSelect(TupleTableSlot *slot,
1280 * get the heap tuple out of the tuple table slot
1283 attrtype = slot->ttc_tupleDescriptor;
1286 * insert the tuple into the "into relation"
1288 * XXX this probably ought to be replaced by a separate destination
1290 if (estate->es_into_relation_descriptor != NULL)
1292 heap_insert(estate->es_into_relation_descriptor, tuple,
1293 estate->es_snapshot->curcid);
1298 * send the tuple to the destination
1300 (*dest->receiveTuple) (tuple, attrtype, dest);
1302 (estate->es_processed)++;
1305 /* ----------------------------------------------------------------
1308 * INSERTs are trickier.. we have to insert the tuple into
1309 * the base relation and insert appropriate tuples into the
1311 * ----------------------------------------------------------------
1314 ExecInsert(TupleTableSlot *slot,
1315 ItemPointer tupleid,
1319 ResultRelInfo *resultRelInfo;
1320 Relation resultRelationDesc;
1325 * get the heap tuple out of the tuple table slot
1330 * get information on the (current) result relation
1332 resultRelInfo = estate->es_result_relation_info;
1333 resultRelationDesc = resultRelInfo->ri_RelationDesc;
1335 /* BEFORE ROW INSERT Triggers */
1336 if (resultRelInfo->ri_TrigDesc &&
1337 resultRelInfo->ri_TrigDesc->n_before_row[TRIGGER_EVENT_INSERT] > 0)
1341 newtuple = ExecBRInsertTriggers(estate, resultRelInfo, tuple);
1343 if (newtuple == NULL) /* "do nothing" */
1346 if (newtuple != tuple) /* modified by Trigger(s) */
1349 * Insert modified tuple into tuple table slot, replacing the
1350 * original. We assume that it was allocated in per-tuple
1351 * memory context, and therefore will go away by itself. The
1352 * tuple table slot should not try to clear it.
1354 ExecStoreTuple(newtuple, slot, InvalidBuffer, false);
1360 * Check the constraints of the tuple
1362 if (resultRelationDesc->rd_att->constr)
1363 ExecConstraints(resultRelInfo, slot, estate);
1368 newId = heap_insert(resultRelationDesc, tuple,
1369 estate->es_snapshot->curcid);
1372 (estate->es_processed)++;
1373 estate->es_lastoid = newId;
1374 setLastTid(&(tuple->t_self));
1379 * Note: heap_insert adds a new tuple to a relation. As a side effect,
1380 * the tupleid of the new tuple is placed in the new tuple's t_ctid
1383 numIndices = resultRelInfo->ri_NumIndices;
1385 ExecInsertIndexTuples(slot, &(tuple->t_self), estate, false);
1387 /* AFTER ROW INSERT Triggers */
1388 ExecARInsertTriggers(estate, resultRelInfo, tuple);
1391 /* ----------------------------------------------------------------
1394 * DELETE is like UPDATE, we delete the tuple and its
1396 * ----------------------------------------------------------------
1399 ExecDelete(TupleTableSlot *slot,
1400 ItemPointer tupleid,
1403 ResultRelInfo *resultRelInfo;
1404 Relation resultRelationDesc;
1405 ItemPointerData ctid;
1409 * get information on the (current) result relation
1411 resultRelInfo = estate->es_result_relation_info;
1412 resultRelationDesc = resultRelInfo->ri_RelationDesc;
1414 /* BEFORE ROW DELETE Triggers */
1415 if (resultRelInfo->ri_TrigDesc &&
1416 resultRelInfo->ri_TrigDesc->n_before_row[TRIGGER_EVENT_DELETE] > 0)
1420 dodelete = ExecBRDeleteTriggers(estate, resultRelInfo, tupleid,
1421 estate->es_snapshot->curcid);
1423 if (!dodelete) /* "do nothing" */
1431 result = heap_delete(resultRelationDesc, tupleid,
1433 estate->es_snapshot->curcid,
1434 estate->es_crosscheck_snapshot,
1435 true /* wait for commit */);
1438 case HeapTupleSelfUpdated:
1439 /* already deleted by self; nothing to do */
1442 case HeapTupleMayBeUpdated:
1445 case HeapTupleUpdated:
1446 if (IsXactIsoLevelSerializable)
1448 (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
1449 errmsg("could not serialize access due to concurrent update")));
1450 else if (!(ItemPointerEquals(tupleid, &ctid)))
1452 TupleTableSlot *epqslot = EvalPlanQual(estate,
1453 resultRelInfo->ri_RangeTableIndex, &ctid);
1455 if (!TupIsNull(epqslot))
1461 /* tuple already deleted; nothing to do */
1465 elog(ERROR, "unrecognized heap_delete status: %u", result);
1470 (estate->es_processed)++;
1473 * Note: Normally one would think that we have to delete index tuples
1474 * associated with the heap tuple now..
1476 * ... but in POSTGRES, we have no need to do this because the vacuum
1477 * daemon automatically opens an index scan and deletes index tuples
1478 * when it finds deleted heap tuples. -cim 9/27/89
1481 /* AFTER ROW DELETE Triggers */
1482 ExecARDeleteTriggers(estate, resultRelInfo, tupleid);
1485 /* ----------------------------------------------------------------
1488 * note: we can't run UPDATE queries with transactions
1489 * off because UPDATEs are actually INSERTs and our
1490 * scan will mistakenly loop forever, updating the tuple
1491 * it just inserted.. This should be fixed but until it
1492 * is, we don't want to get stuck in an infinite loop
1493 * which corrupts your database..
1494 * ----------------------------------------------------------------
1497 ExecUpdate(TupleTableSlot *slot,
1498 ItemPointer tupleid,
1502 ResultRelInfo *resultRelInfo;
1503 Relation resultRelationDesc;
1504 ItemPointerData ctid;
1509 * abort the operation if not running transactions
1511 if (IsBootstrapProcessingMode())
1512 elog(ERROR, "cannot UPDATE during bootstrap");
1515 * get the heap tuple out of the tuple table slot
1520 * get information on the (current) result relation
1522 resultRelInfo = estate->es_result_relation_info;
1523 resultRelationDesc = resultRelInfo->ri_RelationDesc;
1525 /* BEFORE ROW UPDATE Triggers */
1526 if (resultRelInfo->ri_TrigDesc &&
1527 resultRelInfo->ri_TrigDesc->n_before_row[TRIGGER_EVENT_UPDATE] > 0)
1531 newtuple = ExecBRUpdateTriggers(estate, resultRelInfo,
1533 estate->es_snapshot->curcid);
1535 if (newtuple == NULL) /* "do nothing" */
1538 if (newtuple != tuple) /* modified by Trigger(s) */
1541 * Insert modified tuple into tuple table slot, replacing the
1542 * original. We assume that it was allocated in per-tuple
1543 * memory context, and therefore will go away by itself. The
1544 * tuple table slot should not try to clear it.
1546 ExecStoreTuple(newtuple, slot, InvalidBuffer, false);
1552 * Check the constraints of the tuple
1554 * If we generate a new candidate tuple after EvalPlanQual testing, we
1555 * must loop back here and recheck constraints. (We don't need to
1556 * redo triggers, however. If there are any BEFORE triggers then
1557 * trigger.c will have done mark4update to lock the correct tuple, so
1558 * there's no need to do them again.)
1561 if (resultRelationDesc->rd_att->constr)
1562 ExecConstraints(resultRelInfo, slot, estate);
1565 * replace the heap tuple
1567 result = heap_update(resultRelationDesc, tupleid, tuple,
1569 estate->es_snapshot->curcid,
1570 estate->es_crosscheck_snapshot,
1571 true /* wait for commit */);
1574 case HeapTupleSelfUpdated:
1575 /* already deleted by self; nothing to do */
1578 case HeapTupleMayBeUpdated:
1581 case HeapTupleUpdated:
1582 if (IsXactIsoLevelSerializable)
1584 (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
1585 errmsg("could not serialize access due to concurrent update")));
1586 else if (!(ItemPointerEquals(tupleid, &ctid)))
1588 TupleTableSlot *epqslot = EvalPlanQual(estate,
1589 resultRelInfo->ri_RangeTableIndex, &ctid);
1591 if (!TupIsNull(epqslot))
1594 tuple = ExecRemoveJunk(estate->es_junkFilter, epqslot);
1595 slot = ExecStoreTuple(tuple,
1596 estate->es_junkFilter->jf_resultSlot,
1597 InvalidBuffer, true);
1601 /* tuple already deleted; nothing to do */
1605 elog(ERROR, "unrecognized heap_update status: %u", result);
1610 (estate->es_processed)++;
1613 * Note: instead of having to update the old index tuples associated
1614 * with the heap tuple, all we do is form and insert new index tuples.
1615 * This is because UPDATEs are actually DELETEs and INSERTs and index
1616 * tuple deletion is done automagically by the vacuum daemon. All we
1617 * do is insert new index tuples. -cim 9/27/89
1623 * heap_update updates a tuple in the base relation by invalidating it
1624 * and then inserting a new tuple to the relation. As a side effect,
1625 * the tupleid of the new tuple is placed in the new tuple's t_ctid
1626 * field. So we now insert index tuples using the new tupleid stored
1630 numIndices = resultRelInfo->ri_NumIndices;
1632 ExecInsertIndexTuples(slot, &(tuple->t_self), estate, false);
1634 /* AFTER ROW UPDATE Triggers */
1635 ExecARUpdateTriggers(estate, resultRelInfo, tupleid, tuple);
1639 ExecRelCheck(ResultRelInfo *resultRelInfo,
1640 TupleTableSlot *slot, EState *estate)
1642 Relation rel = resultRelInfo->ri_RelationDesc;
1643 int ncheck = rel->rd_att->constr->num_check;
1644 ConstrCheck *check = rel->rd_att->constr->check;
1645 ExprContext *econtext;
1646 MemoryContext oldContext;
1651 * If first time through for this result relation, build expression
1652 * nodetrees for rel's constraint expressions. Keep them in the
1653 * per-query memory context so they'll survive throughout the query.
1655 if (resultRelInfo->ri_ConstraintExprs == NULL)
1657 oldContext = MemoryContextSwitchTo(estate->es_query_cxt);
1658 resultRelInfo->ri_ConstraintExprs =
1659 (List **) palloc(ncheck * sizeof(List *));
1660 for (i = 0; i < ncheck; i++)
1662 /* ExecQual wants implicit-AND form */
1663 qual = make_ands_implicit(stringToNode(check[i].ccbin));
1664 resultRelInfo->ri_ConstraintExprs[i] = (List *)
1665 ExecPrepareExpr((Expr *) qual, estate);
1667 MemoryContextSwitchTo(oldContext);
1671 * We will use the EState's per-tuple context for evaluating
1672 * constraint expressions (creating it if it's not already there).
1674 econtext = GetPerTupleExprContext(estate);
1676 /* Arrange for econtext's scan tuple to be the tuple under test */
1677 econtext->ecxt_scantuple = slot;
1679 /* And evaluate the constraints */
1680 for (i = 0; i < ncheck; i++)
1682 qual = resultRelInfo->ri_ConstraintExprs[i];
1685 * NOTE: SQL92 specifies that a NULL result from a constraint
1686 * expression is not to be treated as a failure. Therefore, tell
1687 * ExecQual to return TRUE for NULL.
1689 if (!ExecQual(qual, econtext, true))
1690 return check[i].ccname;
1693 /* NULL result means no error */
1698 ExecConstraints(ResultRelInfo *resultRelInfo,
1699 TupleTableSlot *slot, EState *estate)
1701 Relation rel = resultRelInfo->ri_RelationDesc;
1702 HeapTuple tuple = slot->val;
1703 TupleConstr *constr = rel->rd_att->constr;
1707 if (constr->has_not_null)
1709 int natts = rel->rd_att->natts;
1712 for (attrChk = 1; attrChk <= natts; attrChk++)
1714 if (rel->rd_att->attrs[attrChk - 1]->attnotnull &&
1715 heap_attisnull(tuple, attrChk))
1717 (errcode(ERRCODE_NOT_NULL_VIOLATION),
1718 errmsg("null value in column \"%s\" violates not-null constraint",
1719 NameStr(rel->rd_att->attrs[attrChk - 1]->attname))));
1723 if (constr->num_check > 0)
1727 if ((failed = ExecRelCheck(resultRelInfo, slot, estate)) != NULL)
1729 (errcode(ERRCODE_CHECK_VIOLATION),
1730 errmsg("new row for relation \"%s\" violates check constraint \"%s\"",
1731 RelationGetRelationName(rel), failed)));
1736 * Check a modified tuple to see if we want to process its updated version
1737 * under READ COMMITTED rules.
1739 * See backend/executor/README for some info about how this works.
1742 EvalPlanQual(EState *estate, Index rti, ItemPointer tid)
1747 HeapTupleData tuple;
1748 HeapTuple copyTuple = NULL;
1754 * find relation containing target tuple
1756 if (estate->es_result_relation_info != NULL &&
1757 estate->es_result_relation_info->ri_RangeTableIndex == rti)
1758 relation = estate->es_result_relation_info->ri_RelationDesc;
1764 foreach(l, estate->es_rowMark)
1766 if (((execRowMark *) lfirst(l))->rti == rti)
1768 relation = ((execRowMark *) lfirst(l))->relation;
1772 if (relation == NULL)
1773 elog(ERROR, "could not find RowMark for RT index %u", rti);
1779 * Loop here to deal with updated or busy tuples
1781 tuple.t_self = *tid;
1786 if (heap_fetch(relation, SnapshotDirty, &tuple, &buffer, false, NULL))
1788 TransactionId xwait = SnapshotDirty->xmax;
1790 /* xmin should not be dirty... */
1791 if (TransactionIdIsValid(SnapshotDirty->xmin))
1792 elog(ERROR, "t_xmin is uncommitted in tuple to be updated");
1795 * If tuple is being updated by other transaction then we have
1796 * to wait for its commit/abort.
1798 if (TransactionIdIsValid(xwait))
1800 ReleaseBuffer(buffer);
1801 XactLockTableWait(xwait);
1806 * We got tuple - now copy it for use by recheck query.
1808 copyTuple = heap_copytuple(&tuple);
1809 ReleaseBuffer(buffer);
1814 * Oops! Invalid tuple. Have to check is it updated or deleted.
1815 * Note that it's possible to get invalid SnapshotDirty->tid if
1816 * tuple updated by this transaction. Have we to check this ?
1818 if (ItemPointerIsValid(&(SnapshotDirty->tid)) &&
1819 !(ItemPointerEquals(&(tuple.t_self), &(SnapshotDirty->tid))))
1821 /* updated, so look at the updated copy */
1822 tuple.t_self = SnapshotDirty->tid;
1827 * Deleted or updated by this transaction; forget it.
1833 * For UPDATE/DELETE we have to return tid of actual row we're
1836 *tid = tuple.t_self;
1839 * Need to run a recheck subquery. Find or create a PQ stack entry.
1841 epq = estate->es_evalPlanQual;
1844 if (epq != NULL && epq->rti == 0)
1846 /* Top PQ stack entry is idle, so re-use it */
1847 Assert(!(estate->es_useEvalPlan) && epq->next == NULL);
1853 * If this is request for another RTE - Ra, - then we have to check
1854 * wasn't PlanQual requested for Ra already and if so then Ra' row was
1855 * updated again and we have to re-start old execution for Ra and
1856 * forget all what we done after Ra was suspended. Cool? -:))
1858 if (epq != NULL && epq->rti != rti &&
1859 epq->estate->es_evTuple[rti - 1] != NULL)
1863 evalPlanQual *oldepq;
1865 /* stop execution */
1866 EvalPlanQualStop(epq);
1867 /* pop previous PlanQual from the stack */
1869 Assert(oldepq && oldepq->rti != 0);
1870 /* push current PQ to freePQ stack */
1873 estate->es_evalPlanQual = epq;
1874 } while (epq->rti != rti);
1878 * If we are requested for another RTE then we have to suspend
1879 * execution of current PlanQual and start execution for new one.
1881 if (epq == NULL || epq->rti != rti)
1883 /* try to reuse plan used previously */
1884 evalPlanQual *newepq = (epq != NULL) ? epq->free : NULL;
1886 if (newepq == NULL) /* first call or freePQ stack is empty */
1888 newepq = (evalPlanQual *) palloc0(sizeof(evalPlanQual));
1889 newepq->free = NULL;
1890 newepq->estate = NULL;
1891 newepq->planstate = NULL;
1895 /* recycle previously used PlanQual */
1896 Assert(newepq->estate == NULL);
1899 /* push current PQ to the stack */
1902 estate->es_evalPlanQual = epq;
1907 Assert(epq->rti == rti);
1910 * Ok - we're requested for the same RTE. Unfortunately we still have
1911 * to end and restart execution of the plan, because ExecReScan
1912 * wouldn't ensure that upper plan nodes would reset themselves. We
1913 * could make that work if insertion of the target tuple were
1914 * integrated with the Param mechanism somehow, so that the upper plan
1915 * nodes know that their children's outputs have changed.
1917 * Note that the stack of free evalPlanQual nodes is quite useless at the
1918 * moment, since it only saves us from pallocing/releasing the
1919 * evalPlanQual nodes themselves. But it will be useful once we
1920 * implement ReScan instead of end/restart for re-using PlanQual
1925 /* stop execution */
1926 EvalPlanQualStop(epq);
1930 * Initialize new recheck query.
1932 * Note: if we were re-using PlanQual plans via ExecReScan, we'd need to
1933 * instead copy down changeable state from the top plan (including
1934 * es_result_relation_info, es_junkFilter) and reset locally
1935 * changeable state in the epq (including es_param_exec_vals,
1938 EvalPlanQualStart(epq, estate, epq->next);
1941 * free old RTE' tuple, if any, and store target tuple where
1942 * relation's scan node will see it
1944 epqstate = epq->estate;
1945 if (epqstate->es_evTuple[rti - 1] != NULL)
1946 heap_freetuple(epqstate->es_evTuple[rti - 1]);
1947 epqstate->es_evTuple[rti - 1] = copyTuple;
1949 return EvalPlanQualNext(estate);
1952 static TupleTableSlot *
1953 EvalPlanQualNext(EState *estate)
1955 evalPlanQual *epq = estate->es_evalPlanQual;
1956 MemoryContext oldcontext;
1957 TupleTableSlot *slot;
1959 Assert(epq->rti != 0);
1962 oldcontext = MemoryContextSwitchTo(epq->estate->es_query_cxt);
1963 slot = ExecProcNode(epq->planstate);
1964 MemoryContextSwitchTo(oldcontext);
1967 * No more tuples for this PQ. Continue previous one.
1969 if (TupIsNull(slot))
1971 evalPlanQual *oldepq;
1973 /* stop execution */
1974 EvalPlanQualStop(epq);
1975 /* pop old PQ from the stack */
1979 /* this is the first (oldest) PQ - mark as free */
1981 estate->es_useEvalPlan = false;
1982 /* and continue Query execution */
1985 Assert(oldepq->rti != 0);
1986 /* push current PQ to freePQ stack */
1989 estate->es_evalPlanQual = epq;
1997 EndEvalPlanQual(EState *estate)
1999 evalPlanQual *epq = estate->es_evalPlanQual;
2001 if (epq->rti == 0) /* plans already shutdowned */
2003 Assert(epq->next == NULL);
2009 evalPlanQual *oldepq;
2011 /* stop execution */
2012 EvalPlanQualStop(epq);
2013 /* pop old PQ from the stack */
2017 /* this is the first (oldest) PQ - mark as free */
2019 estate->es_useEvalPlan = false;
2022 Assert(oldepq->rti != 0);
2023 /* push current PQ to freePQ stack */
2026 estate->es_evalPlanQual = epq;
2031 * Start execution of one level of PlanQual.
2033 * This is a cut-down version of ExecutorStart(): we copy some state from
2034 * the top-level estate rather than initializing it fresh.
2037 EvalPlanQualStart(evalPlanQual *epq, EState *estate, evalPlanQual *priorepq)
2041 MemoryContext oldcontext;
2043 rtsize = length(estate->es_range_table);
2045 epq->estate = epqstate = CreateExecutorState();
2047 oldcontext = MemoryContextSwitchTo(epqstate->es_query_cxt);
2050 * The epqstates share the top query's copy of unchanging state such
2051 * as the snapshot, rangetable, result-rel info, and external Param
2052 * info. They need their own copies of local state, including a tuple
2053 * table, es_param_exec_vals, etc.
2055 epqstate->es_direction = ForwardScanDirection;
2056 epqstate->es_snapshot = estate->es_snapshot;
2057 epqstate->es_crosscheck_snapshot = estate->es_crosscheck_snapshot;
2058 epqstate->es_range_table = estate->es_range_table;
2059 epqstate->es_result_relations = estate->es_result_relations;
2060 epqstate->es_num_result_relations = estate->es_num_result_relations;
2061 epqstate->es_result_relation_info = estate->es_result_relation_info;
2062 epqstate->es_junkFilter = estate->es_junkFilter;
2063 epqstate->es_into_relation_descriptor = estate->es_into_relation_descriptor;
2064 epqstate->es_param_list_info = estate->es_param_list_info;
2065 if (estate->es_topPlan->nParamExec > 0)
2066 epqstate->es_param_exec_vals = (ParamExecData *)
2067 palloc0(estate->es_topPlan->nParamExec * sizeof(ParamExecData));
2068 epqstate->es_rowMark = estate->es_rowMark;
2069 epqstate->es_instrument = estate->es_instrument;
2070 epqstate->es_force_oids = estate->es_force_oids;
2071 epqstate->es_topPlan = estate->es_topPlan;
2074 * Each epqstate must have its own es_evTupleNull state, but all the
2075 * stack entries share es_evTuple state. This allows sub-rechecks to
2076 * inherit the value being examined by an outer recheck.
2078 epqstate->es_evTupleNull = (bool *) palloc0(rtsize * sizeof(bool));
2079 if (priorepq == NULL)
2080 /* first PQ stack entry */
2081 epqstate->es_evTuple = (HeapTuple *)
2082 palloc0(rtsize * sizeof(HeapTuple));
2084 /* later stack entries share the same storage */
2085 epqstate->es_evTuple = priorepq->estate->es_evTuple;
2087 epqstate->es_tupleTable =
2088 ExecCreateTupleTable(estate->es_tupleTable->size);
2090 epq->planstate = ExecInitNode(estate->es_topPlan, epqstate);
2092 MemoryContextSwitchTo(oldcontext);
2096 * End execution of one level of PlanQual.
2098 * This is a cut-down version of ExecutorEnd(); basically we want to do most
2099 * of the normal cleanup, but *not* close result relations (which we are
2100 * just sharing from the outer query).
2103 EvalPlanQualStop(evalPlanQual *epq)
2105 EState *epqstate = epq->estate;
2106 MemoryContext oldcontext;
2108 oldcontext = MemoryContextSwitchTo(epqstate->es_query_cxt);
2110 ExecEndNode(epq->planstate);
2112 ExecDropTupleTable(epqstate->es_tupleTable, true);
2113 epqstate->es_tupleTable = NULL;
2115 if (epqstate->es_evTuple[epq->rti - 1] != NULL)
2117 heap_freetuple(epqstate->es_evTuple[epq->rti - 1]);
2118 epqstate->es_evTuple[epq->rti - 1] = NULL;
2121 MemoryContextSwitchTo(oldcontext);
2123 FreeExecutorState(epqstate);
2126 epq->planstate = NULL;