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11 * The old ExecutorMain() has been replaced by ExecutorStart(),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) 1996-2005, PostgreSQL Global Development Group
25 * Portions Copyright (c) 1994, Regents of the University of California
29 * $PostgreSQL: pgsql/src/backend/executor/execMain.c,v 1.244 2005/03/25 21:57:58 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 "executor/instrument.h"
43 #include "miscadmin.h"
44 #include "optimizer/clauses.h"
45 #include "optimizer/var.h"
46 #include "parser/parsetree.h"
47 #include "utils/acl.h"
48 #include "utils/guc.h"
49 #include "utils/lsyscache.h"
52 typedef struct execRowMark
59 typedef struct evalPlanQual
64 struct evalPlanQual *next; /* stack of active PlanQual plans */
65 struct evalPlanQual *free; /* list of free PlanQual plans */
68 /* decls for local routines only used within this module */
69 static void InitPlan(QueryDesc *queryDesc, bool explainOnly);
70 static void initResultRelInfo(ResultRelInfo *resultRelInfo,
71 Index resultRelationIndex,
75 static TupleTableSlot *ExecutePlan(EState *estate, PlanState *planstate,
78 ScanDirection direction,
80 static void ExecSelect(TupleTableSlot *slot,
83 static void ExecInsert(TupleTableSlot *slot, ItemPointer tupleid,
85 static void ExecDelete(TupleTableSlot *slot, ItemPointer tupleid,
87 static void ExecUpdate(TupleTableSlot *slot, ItemPointer tupleid,
89 static TupleTableSlot *EvalPlanQualNext(EState *estate);
90 static void EndEvalPlanQual(EState *estate);
91 static void ExecCheckRTEPerms(RangeTblEntry *rte);
92 static void ExecCheckXactReadOnly(Query *parsetree);
93 static void EvalPlanQualStart(evalPlanQual *epq, EState *estate,
94 evalPlanQual *priorepq);
95 static void EvalPlanQualStop(evalPlanQual *epq);
97 /* end of local decls */
100 /* ----------------------------------------------------------------
103 * This routine must be called at the beginning of any execution of any
106 * Takes a QueryDesc previously created by CreateQueryDesc (it's not real
107 * clear why we bother to separate the two functions, but...). The tupDesc
108 * field of the QueryDesc is filled in to describe the tuples that will be
109 * returned, and the internal fields (estate and planstate) are set up.
111 * If explainOnly is true, we are not actually intending to run the plan,
112 * only to set up for EXPLAIN; so skip unwanted side-effects.
114 * NB: the CurrentMemoryContext when this is called will become the parent
115 * of the per-query context used for this Executor invocation.
116 * ----------------------------------------------------------------
119 ExecutorStart(QueryDesc *queryDesc, bool explainOnly)
122 MemoryContext oldcontext;
124 /* sanity checks: queryDesc must not be started already */
125 Assert(queryDesc != NULL);
126 Assert(queryDesc->estate == NULL);
129 * If the transaction is read-only, we need to check if any writes are
130 * planned to non-temporary tables.
132 if (XactReadOnly && !explainOnly)
133 ExecCheckXactReadOnly(queryDesc->parsetree);
136 * Build EState, switch into per-query memory context for startup.
138 estate = CreateExecutorState();
139 queryDesc->estate = estate;
141 oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
144 * Fill in parameters, if any, from queryDesc
146 estate->es_param_list_info = queryDesc->params;
148 if (queryDesc->plantree->nParamExec > 0)
149 estate->es_param_exec_vals = (ParamExecData *)
150 palloc0(queryDesc->plantree->nParamExec * sizeof(ParamExecData));
153 * Copy other important information into the EState
155 estate->es_snapshot = queryDesc->snapshot;
156 estate->es_crosscheck_snapshot = queryDesc->crosscheck_snapshot;
157 estate->es_instrument = queryDesc->doInstrument;
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->rStartup) (dest, operation, queryDesc->tupDesc);
225 if (direction == NoMovementScanDirection)
228 result = ExecutePlan(estate,
229 queryDesc->planstate,
238 (*dest->rShutdown) (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)
335 foreach(l, rangeTable)
337 RangeTblEntry *rte = lfirst(l);
339 ExecCheckRTEPerms(rte);
345 * Check access permissions for a single RTE.
348 ExecCheckRTEPerms(RangeTblEntry *rte)
350 AclMode requiredPerms;
355 * If it's a subquery, recursively examine its rangetable.
357 if (rte->rtekind == RTE_SUBQUERY)
359 ExecCheckRTPerms(rte->subquery->rtable);
364 * Otherwise, only plain-relation RTEs need to be checked here.
365 * Function RTEs are checked by init_fcache when the function is
366 * prepared for execution. Join and special RTEs need no checks.
368 if (rte->rtekind != RTE_RELATION)
372 * No work if requiredPerms is empty.
374 requiredPerms = rte->requiredPerms;
375 if (requiredPerms == 0)
381 * userid to check as: current user unless we have a setuid
384 * Note: GetUserId() is presently fast enough that there's no harm in
385 * calling it separately for each RTE. If that stops being true, we
386 * could call it once in ExecCheckRTPerms and pass the userid down
387 * from there. But for now, no need for the extra clutter.
389 userid = rte->checkAsUser ? rte->checkAsUser : GetUserId();
392 * We must have *all* the requiredPerms bits, so use aclmask not
395 if (pg_class_aclmask(relOid, userid, requiredPerms, ACLMASK_ALL)
397 aclcheck_error(ACLCHECK_NO_PRIV, ACL_KIND_CLASS,
398 get_rel_name(relOid));
402 * Check that the query does not imply any writes to non-temp tables.
405 ExecCheckXactReadOnly(Query *parsetree)
410 * CREATE TABLE AS or SELECT INTO?
412 * XXX should we allow this if the destination is temp?
414 if (parsetree->into != NULL)
417 /* Fail if write permissions are requested on any non-temp table */
418 foreach(l, parsetree->rtable)
420 RangeTblEntry *rte = lfirst(l);
422 if (rte->rtekind == RTE_SUBQUERY)
424 ExecCheckXactReadOnly(rte->subquery);
428 if (rte->rtekind != RTE_RELATION)
431 if ((rte->requiredPerms & (~ACL_SELECT)) == 0)
434 if (isTempNamespace(get_rel_namespace(rte->relid)))
444 (errcode(ERRCODE_READ_ONLY_SQL_TRANSACTION),
445 errmsg("transaction is read-only")));
449 /* ----------------------------------------------------------------
452 * Initializes the query plan: open files, allocate storage
453 * and start up the rule manager
454 * ----------------------------------------------------------------
457 InitPlan(QueryDesc *queryDesc, bool explainOnly)
459 CmdType operation = queryDesc->operation;
460 Query *parseTree = queryDesc->parsetree;
461 Plan *plan = queryDesc->plantree;
462 EState *estate = queryDesc->estate;
463 PlanState *planstate;
465 Relation intoRelationDesc;
470 * Do permissions checks. It's sufficient to examine the query's top
471 * rangetable here --- subplan RTEs will be checked during
474 ExecCheckRTPerms(parseTree->rtable);
477 * get information from query descriptor
479 rangeTable = parseTree->rtable;
482 * initialize the node's execution state
484 estate->es_range_table = rangeTable;
487 * if there is a result relation, initialize result relation stuff
489 if (parseTree->resultRelation != 0 && operation != CMD_SELECT)
491 List *resultRelations = parseTree->resultRelations;
492 int numResultRelations;
493 ResultRelInfo *resultRelInfos;
495 if (resultRelations != NIL)
498 * Multiple result relations (due to inheritance)
499 * parseTree->resultRelations identifies them all
501 ResultRelInfo *resultRelInfo;
504 numResultRelations = list_length(resultRelations);
505 resultRelInfos = (ResultRelInfo *)
506 palloc(numResultRelations * sizeof(ResultRelInfo));
507 resultRelInfo = resultRelInfos;
508 foreach(l, resultRelations)
510 initResultRelInfo(resultRelInfo,
514 estate->es_instrument);
521 * Single result relation identified by
522 * parseTree->resultRelation
524 numResultRelations = 1;
525 resultRelInfos = (ResultRelInfo *) palloc(sizeof(ResultRelInfo));
526 initResultRelInfo(resultRelInfos,
527 parseTree->resultRelation,
530 estate->es_instrument);
533 estate->es_result_relations = resultRelInfos;
534 estate->es_num_result_relations = numResultRelations;
535 /* Initialize to first or only result rel */
536 estate->es_result_relation_info = resultRelInfos;
541 * if no result relation, then set state appropriately
543 estate->es_result_relations = NULL;
544 estate->es_num_result_relations = 0;
545 estate->es_result_relation_info = NULL;
549 * Detect whether we're doing SELECT INTO. If so, set the es_into_oids
550 * flag appropriately so that the plan tree will be initialized with
551 * the correct tuple descriptors.
553 do_select_into = false;
555 if (operation == CMD_SELECT && parseTree->into != NULL)
557 do_select_into = true;
558 estate->es_select_into = true;
559 estate->es_into_oids = parseTree->intoHasOids;
563 * Have to lock relations selected for update
565 estate->es_rowMark = NIL;
566 if (parseTree->rowMarks != NIL)
570 foreach(l, parseTree->rowMarks)
572 Index rti = lfirst_int(l);
573 Oid relid = getrelid(rti, rangeTable);
577 relation = heap_open(relid, RowShareLock);
578 erm = (execRowMark *) palloc(sizeof(execRowMark));
579 erm->relation = relation;
581 snprintf(erm->resname, sizeof(erm->resname), "ctid%u", rti);
582 estate->es_rowMark = lappend(estate->es_rowMark, erm);
587 * initialize the executor "tuple" table. We need slots for all the
588 * plan nodes, plus possibly output slots for the junkfilter(s). At
589 * this point we aren't sure if we need junkfilters, so just add slots
590 * for them unconditionally.
593 int nSlots = ExecCountSlotsNode(plan);
595 if (parseTree->resultRelations != NIL)
596 nSlots += list_length(parseTree->resultRelations);
599 estate->es_tupleTable = ExecCreateTupleTable(nSlots);
602 /* mark EvalPlanQual not active */
603 estate->es_topPlan = plan;
604 estate->es_evalPlanQual = NULL;
605 estate->es_evTupleNull = NULL;
606 estate->es_evTuple = NULL;
607 estate->es_useEvalPlan = false;
610 * initialize the private state information for all the nodes in the
611 * query tree. This opens files, allocates storage and leaves us
612 * ready to start processing tuples.
614 planstate = ExecInitNode(plan, estate);
617 * Get the tuple descriptor describing the type of tuples to return.
618 * (this is especially important if we are creating a relation with
621 tupType = ExecGetResultType(planstate);
624 * Initialize the junk filter if needed. SELECT and INSERT queries
625 * need a filter if there are any junk attrs in the tlist. INSERT and
626 * SELECT INTO also need a filter if the plan may return raw disk
627 * tuples (else heap_insert will be scribbling on the source
628 * relation!). UPDATE and DELETE always need a filter, since there's
629 * always a junk 'ctid' attribute present --- no need to look first.
632 bool junk_filter_needed = false;
639 foreach(tlist, plan->targetlist)
641 TargetEntry *tle = (TargetEntry *) lfirst(tlist);
643 if (tle->resdom->resjunk)
645 junk_filter_needed = true;
649 if (!junk_filter_needed &&
650 (operation == CMD_INSERT || do_select_into) &&
651 ExecMayReturnRawTuples(planstate))
652 junk_filter_needed = true;
656 junk_filter_needed = true;
662 if (junk_filter_needed)
665 * If there are multiple result relations, each one needs its
666 * own junk filter. Note this is only possible for
667 * UPDATE/DELETE, so we can't be fooled by some needing a
668 * filter and some not.
670 if (parseTree->resultRelations != NIL)
672 PlanState **appendplans;
674 ResultRelInfo *resultRelInfo;
677 /* Top plan had better be an Append here. */
678 Assert(IsA(plan, Append));
679 Assert(((Append *) plan)->isTarget);
680 Assert(IsA(planstate, AppendState));
681 appendplans = ((AppendState *) planstate)->appendplans;
682 as_nplans = ((AppendState *) planstate)->as_nplans;
683 Assert(as_nplans == estate->es_num_result_relations);
684 resultRelInfo = estate->es_result_relations;
685 for (i = 0; i < as_nplans; i++)
687 PlanState *subplan = appendplans[i];
690 j = ExecInitJunkFilter(subplan->plan->targetlist,
691 resultRelInfo->ri_RelationDesc->rd_att->tdhasoid,
692 ExecAllocTableSlot(estate->es_tupleTable));
693 resultRelInfo->ri_junkFilter = j;
698 * Set active junkfilter too; at this point ExecInitAppend
699 * has already selected an active result relation...
701 estate->es_junkFilter =
702 estate->es_result_relation_info->ri_junkFilter;
706 /* Normal case with just one JunkFilter */
709 j = ExecInitJunkFilter(planstate->plan->targetlist,
711 ExecAllocTableSlot(estate->es_tupleTable));
712 estate->es_junkFilter = j;
713 if (estate->es_result_relation_info)
714 estate->es_result_relation_info->ri_junkFilter = j;
716 /* For SELECT, want to return the cleaned tuple type */
717 if (operation == CMD_SELECT)
718 tupType = j->jf_cleanTupType;
722 estate->es_junkFilter = NULL;
726 * If doing SELECT INTO, initialize the "into" relation. We must wait
727 * till now so we have the "clean" result tuple type to create the new
730 * If EXPLAIN, skip creating the "into" relation.
732 intoRelationDesc = NULL;
734 if (do_select_into && !explainOnly)
743 * find namespace to create in, check permissions
745 intoName = parseTree->into->relname;
746 namespaceId = RangeVarGetCreationNamespace(parseTree->into);
748 aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(),
750 if (aclresult != ACLCHECK_OK)
751 aclcheck_error(aclresult, ACL_KIND_NAMESPACE,
752 get_namespace_name(namespaceId));
755 * have to copy tupType to get rid of constraints
757 tupdesc = CreateTupleDescCopy(tupType);
759 intoRelationId = heap_create_with_catalog(intoName,
768 allowSystemTableMods);
770 FreeTupleDesc(tupdesc);
773 * Advance command counter so that the newly-created relation's
774 * catalog tuples will be visible to heap_open.
776 CommandCounterIncrement();
779 * If necessary, create a TOAST table for the into relation. Note
780 * that AlterTableCreateToastTable ends with
781 * CommandCounterIncrement(), so that the TOAST table will be
782 * visible for insertion.
784 AlterTableCreateToastTable(intoRelationId, true);
787 * And open the constructed table for writing.
789 intoRelationDesc = heap_open(intoRelationId, AccessExclusiveLock);
792 estate->es_into_relation_descriptor = intoRelationDesc;
794 queryDesc->tupDesc = tupType;
795 queryDesc->planstate = planstate;
799 * Initialize ResultRelInfo data for one result relation
802 initResultRelInfo(ResultRelInfo *resultRelInfo,
803 Index resultRelationIndex,
808 Oid resultRelationOid;
809 Relation resultRelationDesc;
811 resultRelationOid = getrelid(resultRelationIndex, rangeTable);
812 resultRelationDesc = heap_open(resultRelationOid, RowExclusiveLock);
814 switch (resultRelationDesc->rd_rel->relkind)
816 case RELKIND_SEQUENCE:
818 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
819 errmsg("cannot change sequence \"%s\"",
820 RelationGetRelationName(resultRelationDesc))));
822 case RELKIND_TOASTVALUE:
824 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
825 errmsg("cannot change TOAST relation \"%s\"",
826 RelationGetRelationName(resultRelationDesc))));
830 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
831 errmsg("cannot change view \"%s\"",
832 RelationGetRelationName(resultRelationDesc))));
836 MemSet(resultRelInfo, 0, sizeof(ResultRelInfo));
837 resultRelInfo->type = T_ResultRelInfo;
838 resultRelInfo->ri_RangeTableIndex = resultRelationIndex;
839 resultRelInfo->ri_RelationDesc = resultRelationDesc;
840 resultRelInfo->ri_NumIndices = 0;
841 resultRelInfo->ri_IndexRelationDescs = NULL;
842 resultRelInfo->ri_IndexRelationInfo = NULL;
843 /* make a copy so as not to depend on relcache info not changing... */
844 resultRelInfo->ri_TrigDesc = CopyTriggerDesc(resultRelationDesc->trigdesc);
845 if (resultRelInfo->ri_TrigDesc)
847 int n = resultRelInfo->ri_TrigDesc->numtriggers;
849 resultRelInfo->ri_TrigFunctions = (FmgrInfo *)
850 palloc0(n * sizeof(FmgrInfo));
852 resultRelInfo->ri_TrigInstrument = InstrAlloc(n);
854 resultRelInfo->ri_TrigInstrument = NULL;
858 resultRelInfo->ri_TrigFunctions = NULL;
859 resultRelInfo->ri_TrigInstrument = NULL;
861 resultRelInfo->ri_ConstraintExprs = NULL;
862 resultRelInfo->ri_junkFilter = NULL;
865 * If there are indices on the result relation, open them and save
866 * descriptors in the result relation info, so that we can add new
867 * index entries for the tuples we add/update. We need not do this
868 * for a DELETE, however, since deletion doesn't affect indexes.
870 if (resultRelationDesc->rd_rel->relhasindex &&
871 operation != CMD_DELETE)
872 ExecOpenIndices(resultRelInfo);
876 * ExecContextForcesOids
878 * This is pretty grotty: when doing INSERT, UPDATE, or SELECT INTO,
879 * we need to ensure that result tuples have space for an OID iff they are
880 * going to be stored into a relation that has OIDs. In other contexts
881 * we are free to choose whether to leave space for OIDs in result tuples
882 * (we generally don't want to, but we do if a physical-tlist optimization
883 * is possible). This routine checks the plan context and returns TRUE if the
884 * choice is forced, FALSE if the choice is not forced. In the TRUE case,
885 * *hasoids is set to the required value.
887 * One reason this is ugly is that all plan nodes in the plan tree will emit
888 * tuples with space for an OID, though we really only need the topmost node
889 * to do so. However, node types like Sort don't project new tuples but just
890 * return their inputs, and in those cases the requirement propagates down
891 * to the input node. Eventually we might make this code smart enough to
892 * recognize how far down the requirement really goes, but for now we just
893 * make all plan nodes do the same thing if the top level forces the choice.
895 * We assume that estate->es_result_relation_info is already set up to
896 * describe the target relation. Note that in an UPDATE that spans an
897 * inheritance tree, some of the target relations may have OIDs and some not.
898 * We have to make the decisions on a per-relation basis as we initialize
899 * each of the child plans of the topmost Append plan.
901 * SELECT INTO is even uglier, because we don't have the INTO relation's
902 * descriptor available when this code runs; we have to look aside at a
903 * flag set by InitPlan().
906 ExecContextForcesOids(PlanState *planstate, bool *hasoids)
908 if (planstate->state->es_select_into)
910 *hasoids = planstate->state->es_into_oids;
915 ResultRelInfo *ri = planstate->state->es_result_relation_info;
919 Relation rel = ri->ri_RelationDesc;
923 *hasoids = rel->rd_rel->relhasoids;
932 /* ----------------------------------------------------------------
935 * Cleans up the query plan -- closes files and frees up storage
937 * NOTE: we are no longer very worried about freeing storage per se
938 * in this code; FreeExecutorState should be guaranteed to release all
939 * memory that needs to be released. What we are worried about doing
940 * is closing relations and dropping buffer pins. Thus, for example,
941 * tuple tables must be cleared or dropped to ensure pins are released.
942 * ----------------------------------------------------------------
945 ExecEndPlan(PlanState *planstate, EState *estate)
947 ResultRelInfo *resultRelInfo;
952 * shut down any PlanQual processing we were doing
954 if (estate->es_evalPlanQual != NULL)
955 EndEvalPlanQual(estate);
958 * shut down the node-type-specific query processing
960 ExecEndNode(planstate);
963 * destroy the executor "tuple" table.
965 ExecDropTupleTable(estate->es_tupleTable, true);
966 estate->es_tupleTable = NULL;
969 * close the result relation(s) if any, but hold locks until xact
972 resultRelInfo = estate->es_result_relations;
973 for (i = estate->es_num_result_relations; i > 0; i--)
975 /* Close indices and then the relation itself */
976 ExecCloseIndices(resultRelInfo);
977 heap_close(resultRelInfo->ri_RelationDesc, NoLock);
982 * close the "into" relation if necessary, again keeping lock
984 if (estate->es_into_relation_descriptor != NULL)
985 heap_close(estate->es_into_relation_descriptor, NoLock);
988 * close any relations selected FOR UPDATE, again keeping locks
990 foreach(l, estate->es_rowMark)
992 execRowMark *erm = lfirst(l);
994 heap_close(erm->relation, NoLock);
998 /* ----------------------------------------------------------------
1001 * processes the query plan to retrieve 'numberTuples' tuples in the
1002 * direction specified.
1004 * Retrieves all tuples if numberTuples is 0
1006 * result is either a slot containing the last tuple in the case
1007 * of a SELECT or NULL otherwise.
1009 * Note: the ctid attribute is a 'junk' attribute that is removed before the
1011 * ----------------------------------------------------------------
1013 static TupleTableSlot *
1014 ExecutePlan(EState *estate,
1015 PlanState *planstate,
1018 ScanDirection direction,
1021 JunkFilter *junkfilter;
1022 TupleTableSlot *slot;
1023 ItemPointer tupleid = NULL;
1024 ItemPointerData tuple_ctid;
1025 long current_tuple_count;
1026 TupleTableSlot *result;
1029 * initialize local variables
1032 current_tuple_count = 0;
1036 * Set the direction.
1038 estate->es_direction = direction;
1041 * Process BEFORE EACH STATEMENT triggers
1046 ExecBSUpdateTriggers(estate, estate->es_result_relation_info);
1049 ExecBSDeleteTriggers(estate, estate->es_result_relation_info);
1052 ExecBSInsertTriggers(estate, estate->es_result_relation_info);
1060 * Loop until we've processed the proper number of tuples from the
1066 /* Reset the per-output-tuple exprcontext */
1067 ResetPerTupleExprContext(estate);
1070 * Execute the plan and obtain a tuple
1073 if (estate->es_useEvalPlan)
1075 slot = EvalPlanQualNext(estate);
1076 if (TupIsNull(slot))
1077 slot = ExecProcNode(planstate);
1080 slot = ExecProcNode(planstate);
1083 * if the tuple is null, then we assume there is nothing more to
1084 * process so we just return null...
1086 if (TupIsNull(slot))
1093 * if we have a junk filter, then project a new tuple with the
1096 * Store this new "clean" tuple in the junkfilter's resultSlot.
1097 * (Formerly, we stored it back over the "dirty" tuple, which is
1098 * WRONG because that tuple slot has the wrong descriptor.)
1100 * Also, extract all the junk information we need.
1102 if ((junkfilter = estate->es_junkFilter) != NULL)
1108 * extract the 'ctid' junk attribute.
1110 if (operation == CMD_UPDATE || operation == CMD_DELETE)
1112 if (!ExecGetJunkAttribute(junkfilter,
1117 elog(ERROR, "could not find junk ctid column");
1119 /* shouldn't ever get a null result... */
1121 elog(ERROR, "ctid is NULL");
1123 tupleid = (ItemPointer) DatumGetPointer(datum);
1124 tuple_ctid = *tupleid; /* make sure we don't free the
1126 tupleid = &tuple_ctid;
1128 else if (estate->es_rowMark != NIL)
1133 foreach(l, estate->es_rowMark)
1135 execRowMark *erm = lfirst(l);
1137 HeapTupleData tuple;
1138 TupleTableSlot *newSlot;
1141 if (!ExecGetJunkAttribute(junkfilter,
1146 elog(ERROR, "could not find junk \"%s\" column",
1149 /* shouldn't ever get a null result... */
1151 elog(ERROR, "\"%s\" is NULL", erm->resname);
1153 tuple.t_self = *((ItemPointer) DatumGetPointer(datum));
1154 test = heap_mark4update(erm->relation, &tuple, &buffer,
1155 estate->es_snapshot->curcid);
1156 ReleaseBuffer(buffer);
1159 case HeapTupleSelfUpdated:
1160 /* treat it as deleted; do not process */
1163 case HeapTupleMayBeUpdated:
1166 case HeapTupleUpdated:
1167 if (IsXactIsoLevelSerializable)
1169 (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
1170 errmsg("could not serialize access due to concurrent update")));
1171 if (!(ItemPointerEquals(&(tuple.t_self),
1172 (ItemPointer) DatumGetPointer(datum))))
1174 newSlot = EvalPlanQual(estate, erm->rti, &(tuple.t_self));
1175 if (!(TupIsNull(newSlot)))
1178 estate->es_useEvalPlan = true;
1184 * if tuple was deleted or PlanQual failed for
1185 * updated tuple - we must not return this
1191 elog(ERROR, "unrecognized heap_mark4update status: %u",
1199 * Finally create a new "clean" tuple with all junk attributes
1202 slot = ExecFilterJunk(junkfilter, slot);
1206 * now that we have a tuple, do the appropriate thing with it..
1207 * either return it to the user, add it to a relation someplace,
1208 * delete it from a relation, or modify some of its attributes.
1213 ExecSelect(slot, /* slot containing tuple */
1214 dest, /* destination's tuple-receiver obj */
1220 ExecInsert(slot, tupleid, estate);
1225 ExecDelete(slot, tupleid, estate);
1230 ExecUpdate(slot, tupleid, estate);
1235 elog(ERROR, "unrecognized operation code: %d",
1242 * check our tuple count.. if we've processed the proper number
1243 * then quit, else loop again and process more tuples. Zero
1244 * numberTuples means no limit.
1246 current_tuple_count++;
1247 if (numberTuples && numberTuples == current_tuple_count)
1252 * Process AFTER EACH STATEMENT triggers
1257 ExecASUpdateTriggers(estate, estate->es_result_relation_info);
1260 ExecASDeleteTriggers(estate, estate->es_result_relation_info);
1263 ExecASInsertTriggers(estate, estate->es_result_relation_info);
1271 * here, result is either a slot containing a tuple in the case of a
1272 * SELECT or NULL otherwise.
1277 /* ----------------------------------------------------------------
1280 * SELECTs are easy.. we just pass the tuple to the appropriate
1281 * print function. The only complexity is when we do a
1282 * "SELECT INTO", in which case we insert the tuple into
1283 * the appropriate relation (note: this is a newly created relation
1284 * so we don't need to worry about indices or locks.)
1285 * ----------------------------------------------------------------
1288 ExecSelect(TupleTableSlot *slot,
1293 * insert the tuple into the "into relation"
1295 * XXX this probably ought to be replaced by a separate destination
1297 if (estate->es_into_relation_descriptor != NULL)
1301 tuple = ExecCopySlotTuple(slot);
1302 heap_insert(estate->es_into_relation_descriptor, tuple,
1303 estate->es_snapshot->curcid);
1304 /* we know there are no indexes to update */
1305 heap_freetuple(tuple);
1310 * send the tuple to the destination
1312 (*dest->receiveSlot) (slot, dest);
1314 (estate->es_processed)++;
1317 /* ----------------------------------------------------------------
1320 * INSERTs are trickier.. we have to insert the tuple into
1321 * the base relation and insert appropriate tuples into the
1323 * ----------------------------------------------------------------
1326 ExecInsert(TupleTableSlot *slot,
1327 ItemPointer tupleid,
1331 ResultRelInfo *resultRelInfo;
1332 Relation resultRelationDesc;
1337 * get the heap tuple out of the tuple table slot, making sure
1338 * we have a writable copy
1340 tuple = ExecMaterializeSlot(slot);
1343 * get information on the (current) result relation
1345 resultRelInfo = estate->es_result_relation_info;
1346 resultRelationDesc = resultRelInfo->ri_RelationDesc;
1348 /* BEFORE ROW INSERT Triggers */
1349 if (resultRelInfo->ri_TrigDesc &&
1350 resultRelInfo->ri_TrigDesc->n_before_row[TRIGGER_EVENT_INSERT] > 0)
1354 newtuple = ExecBRInsertTriggers(estate, resultRelInfo, tuple);
1356 if (newtuple == NULL) /* "do nothing" */
1359 if (newtuple != tuple) /* modified by Trigger(s) */
1362 * Insert modified tuple into tuple table slot, replacing the
1363 * original. We assume that it was allocated in per-tuple
1364 * memory context, and therefore will go away by itself. The
1365 * tuple table slot should not try to clear it.
1367 ExecStoreTuple(newtuple, slot, InvalidBuffer, false);
1373 * Check the constraints of the tuple
1375 if (resultRelationDesc->rd_att->constr)
1376 ExecConstraints(resultRelInfo, slot, estate);
1381 newId = heap_insert(resultRelationDesc, tuple,
1382 estate->es_snapshot->curcid);
1385 (estate->es_processed)++;
1386 estate->es_lastoid = newId;
1387 setLastTid(&(tuple->t_self));
1392 * Note: heap_insert adds a new tuple to a relation. As a side effect,
1393 * the tupleid of the new tuple is placed in the new tuple's t_ctid
1396 numIndices = resultRelInfo->ri_NumIndices;
1398 ExecInsertIndexTuples(slot, &(tuple->t_self), estate, false);
1400 /* AFTER ROW INSERT Triggers */
1401 ExecARInsertTriggers(estate, resultRelInfo, tuple);
1404 /* ----------------------------------------------------------------
1407 * DELETE is like UPDATE, we delete the tuple and its
1409 * ----------------------------------------------------------------
1412 ExecDelete(TupleTableSlot *slot,
1413 ItemPointer tupleid,
1416 ResultRelInfo *resultRelInfo;
1417 Relation resultRelationDesc;
1418 ItemPointerData ctid;
1422 * get information on the (current) result relation
1424 resultRelInfo = estate->es_result_relation_info;
1425 resultRelationDesc = resultRelInfo->ri_RelationDesc;
1427 /* BEFORE ROW DELETE Triggers */
1428 if (resultRelInfo->ri_TrigDesc &&
1429 resultRelInfo->ri_TrigDesc->n_before_row[TRIGGER_EVENT_DELETE] > 0)
1433 dodelete = ExecBRDeleteTriggers(estate, resultRelInfo, tupleid,
1434 estate->es_snapshot->curcid);
1436 if (!dodelete) /* "do nothing" */
1443 * Note: if es_crosscheck_snapshot isn't InvalidSnapshot, we check that
1444 * the row to be deleted is visible to that snapshot, and throw a can't-
1445 * serialize error if not. This is a special-case behavior needed for
1446 * referential integrity updates in serializable transactions.
1449 result = heap_delete(resultRelationDesc, tupleid,
1451 estate->es_snapshot->curcid,
1452 estate->es_crosscheck_snapshot,
1453 true /* wait for commit */ );
1456 case HeapTupleSelfUpdated:
1457 /* already deleted by self; nothing to do */
1460 case HeapTupleMayBeUpdated:
1463 case HeapTupleUpdated:
1464 if (IsXactIsoLevelSerializable)
1466 (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
1467 errmsg("could not serialize access due to concurrent update")));
1468 else if (!(ItemPointerEquals(tupleid, &ctid)))
1470 TupleTableSlot *epqslot = EvalPlanQual(estate,
1471 resultRelInfo->ri_RangeTableIndex, &ctid);
1473 if (!TupIsNull(epqslot))
1479 /* tuple already deleted; nothing to do */
1483 elog(ERROR, "unrecognized heap_delete status: %u", result);
1488 (estate->es_processed)++;
1491 * Note: Normally one would think that we have to delete index tuples
1492 * associated with the heap tuple now..
1494 * ... but in POSTGRES, we have no need to do this because the vacuum
1495 * daemon automatically opens an index scan and deletes index tuples
1496 * when it finds deleted heap tuples. -cim 9/27/89
1499 /* AFTER ROW DELETE Triggers */
1500 ExecARDeleteTriggers(estate, resultRelInfo, tupleid);
1503 /* ----------------------------------------------------------------
1506 * note: we can't run UPDATE queries with transactions
1507 * off because UPDATEs are actually INSERTs and our
1508 * scan will mistakenly loop forever, updating the tuple
1509 * it just inserted.. This should be fixed but until it
1510 * is, we don't want to get stuck in an infinite loop
1511 * which corrupts your database..
1512 * ----------------------------------------------------------------
1515 ExecUpdate(TupleTableSlot *slot,
1516 ItemPointer tupleid,
1520 ResultRelInfo *resultRelInfo;
1521 Relation resultRelationDesc;
1522 ItemPointerData ctid;
1527 * abort the operation if not running transactions
1529 if (IsBootstrapProcessingMode())
1530 elog(ERROR, "cannot UPDATE during bootstrap");
1533 * get the heap tuple out of the tuple table slot, making sure
1534 * we have a writable copy
1536 tuple = ExecMaterializeSlot(slot);
1539 * get information on the (current) result relation
1541 resultRelInfo = estate->es_result_relation_info;
1542 resultRelationDesc = resultRelInfo->ri_RelationDesc;
1544 /* BEFORE ROW UPDATE Triggers */
1545 if (resultRelInfo->ri_TrigDesc &&
1546 resultRelInfo->ri_TrigDesc->n_before_row[TRIGGER_EVENT_UPDATE] > 0)
1550 newtuple = ExecBRUpdateTriggers(estate, resultRelInfo,
1552 estate->es_snapshot->curcid);
1554 if (newtuple == NULL) /* "do nothing" */
1557 if (newtuple != tuple) /* modified by Trigger(s) */
1560 * Insert modified tuple into tuple table slot, replacing the
1561 * original. We assume that it was allocated in per-tuple
1562 * memory context, and therefore will go away by itself. The
1563 * tuple table slot should not try to clear it.
1565 ExecStoreTuple(newtuple, slot, InvalidBuffer, false);
1571 * Check the constraints of the tuple
1573 * If we generate a new candidate tuple after EvalPlanQual testing, we
1574 * must loop back here and recheck constraints. (We don't need to
1575 * redo triggers, however. If there are any BEFORE triggers then
1576 * trigger.c will have done mark4update to lock the correct tuple, so
1577 * there's no need to do them again.)
1580 if (resultRelationDesc->rd_att->constr)
1581 ExecConstraints(resultRelInfo, slot, estate);
1584 * replace the heap tuple
1586 * Note: if es_crosscheck_snapshot isn't InvalidSnapshot, we check that
1587 * the row to be updated is visible to that snapshot, and throw a can't-
1588 * serialize error if not. This is a special-case behavior needed for
1589 * referential integrity updates in serializable transactions.
1591 result = heap_update(resultRelationDesc, tupleid, tuple,
1593 estate->es_snapshot->curcid,
1594 estate->es_crosscheck_snapshot,
1595 true /* wait for commit */ );
1598 case HeapTupleSelfUpdated:
1599 /* already deleted by self; nothing to do */
1602 case HeapTupleMayBeUpdated:
1605 case HeapTupleUpdated:
1606 if (IsXactIsoLevelSerializable)
1608 (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
1609 errmsg("could not serialize access due to concurrent update")));
1610 else if (!(ItemPointerEquals(tupleid, &ctid)))
1612 TupleTableSlot *epqslot = EvalPlanQual(estate,
1613 resultRelInfo->ri_RangeTableIndex, &ctid);
1615 if (!TupIsNull(epqslot))
1618 slot = ExecFilterJunk(estate->es_junkFilter, epqslot);
1619 tuple = ExecMaterializeSlot(slot);
1623 /* tuple already deleted; nothing to do */
1627 elog(ERROR, "unrecognized heap_update status: %u", result);
1632 (estate->es_processed)++;
1635 * Note: instead of having to update the old index tuples associated
1636 * with the heap tuple, all we do is form and insert new index tuples.
1637 * This is because UPDATEs are actually DELETEs and INSERTs and index
1638 * tuple deletion is done automagically by the vacuum daemon. All we
1639 * do is insert new index tuples. -cim 9/27/89
1645 * heap_update updates a tuple in the base relation by invalidating it
1646 * and then inserting a new tuple to the relation. As a side effect,
1647 * the tupleid of the new tuple is placed in the new tuple's t_ctid
1648 * field. So we now insert index tuples using the new tupleid stored
1652 numIndices = resultRelInfo->ri_NumIndices;
1654 ExecInsertIndexTuples(slot, &(tuple->t_self), estate, false);
1656 /* AFTER ROW UPDATE Triggers */
1657 ExecARUpdateTriggers(estate, resultRelInfo, tupleid, tuple);
1661 ExecRelCheck(ResultRelInfo *resultRelInfo,
1662 TupleTableSlot *slot, EState *estate)
1664 Relation rel = resultRelInfo->ri_RelationDesc;
1665 int ncheck = rel->rd_att->constr->num_check;
1666 ConstrCheck *check = rel->rd_att->constr->check;
1667 ExprContext *econtext;
1668 MemoryContext oldContext;
1673 * If first time through for this result relation, build expression
1674 * nodetrees for rel's constraint expressions. Keep them in the
1675 * per-query memory context so they'll survive throughout the query.
1677 if (resultRelInfo->ri_ConstraintExprs == NULL)
1679 oldContext = MemoryContextSwitchTo(estate->es_query_cxt);
1680 resultRelInfo->ri_ConstraintExprs =
1681 (List **) palloc(ncheck * sizeof(List *));
1682 for (i = 0; i < ncheck; i++)
1684 /* ExecQual wants implicit-AND form */
1685 qual = make_ands_implicit(stringToNode(check[i].ccbin));
1686 resultRelInfo->ri_ConstraintExprs[i] = (List *)
1687 ExecPrepareExpr((Expr *) qual, estate);
1689 MemoryContextSwitchTo(oldContext);
1693 * We will use the EState's per-tuple context for evaluating
1694 * constraint expressions (creating it if it's not already there).
1696 econtext = GetPerTupleExprContext(estate);
1698 /* Arrange for econtext's scan tuple to be the tuple under test */
1699 econtext->ecxt_scantuple = slot;
1701 /* And evaluate the constraints */
1702 for (i = 0; i < ncheck; i++)
1704 qual = resultRelInfo->ri_ConstraintExprs[i];
1707 * NOTE: SQL92 specifies that a NULL result from a constraint
1708 * expression is not to be treated as a failure. Therefore, tell
1709 * ExecQual to return TRUE for NULL.
1711 if (!ExecQual(qual, econtext, true))
1712 return check[i].ccname;
1715 /* NULL result means no error */
1720 ExecConstraints(ResultRelInfo *resultRelInfo,
1721 TupleTableSlot *slot, EState *estate)
1723 Relation rel = resultRelInfo->ri_RelationDesc;
1724 TupleConstr *constr = rel->rd_att->constr;
1728 if (constr->has_not_null)
1730 int natts = rel->rd_att->natts;
1733 for (attrChk = 1; attrChk <= natts; attrChk++)
1735 if (rel->rd_att->attrs[attrChk - 1]->attnotnull &&
1736 slot_attisnull(slot, attrChk))
1738 (errcode(ERRCODE_NOT_NULL_VIOLATION),
1739 errmsg("null value in column \"%s\" violates not-null constraint",
1740 NameStr(rel->rd_att->attrs[attrChk - 1]->attname))));
1744 if (constr->num_check > 0)
1748 if ((failed = ExecRelCheck(resultRelInfo, slot, estate)) != NULL)
1750 (errcode(ERRCODE_CHECK_VIOLATION),
1751 errmsg("new row for relation \"%s\" violates check constraint \"%s\"",
1752 RelationGetRelationName(rel), failed)));
1757 * Check a modified tuple to see if we want to process its updated version
1758 * under READ COMMITTED rules.
1760 * See backend/executor/README for some info about how this works.
1763 EvalPlanQual(EState *estate, Index rti, ItemPointer tid)
1768 HeapTupleData tuple;
1769 HeapTuple copyTuple = NULL;
1775 * find relation containing target tuple
1777 if (estate->es_result_relation_info != NULL &&
1778 estate->es_result_relation_info->ri_RangeTableIndex == rti)
1779 relation = estate->es_result_relation_info->ri_RelationDesc;
1785 foreach(l, estate->es_rowMark)
1787 if (((execRowMark *) lfirst(l))->rti == rti)
1789 relation = ((execRowMark *) lfirst(l))->relation;
1793 if (relation == NULL)
1794 elog(ERROR, "could not find RowMark for RT index %u", rti);
1800 * Loop here to deal with updated or busy tuples
1802 tuple.t_self = *tid;
1807 if (heap_fetch(relation, SnapshotDirty, &tuple, &buffer, false, NULL))
1809 TransactionId xwait = SnapshotDirty->xmax;
1811 /* xmin should not be dirty... */
1812 if (TransactionIdIsValid(SnapshotDirty->xmin))
1813 elog(ERROR, "t_xmin is uncommitted in tuple to be updated");
1816 * If tuple is being updated by other transaction then we have
1817 * to wait for its commit/abort.
1819 if (TransactionIdIsValid(xwait))
1821 ReleaseBuffer(buffer);
1822 XactLockTableWait(xwait);
1827 * We got tuple - now copy it for use by recheck query.
1829 copyTuple = heap_copytuple(&tuple);
1830 ReleaseBuffer(buffer);
1835 * Oops! Invalid tuple. Have to check is it updated or deleted.
1836 * Note that it's possible to get invalid SnapshotDirty->tid if
1837 * tuple updated by this transaction. Have we to check this ?
1839 if (ItemPointerIsValid(&(SnapshotDirty->tid)) &&
1840 !(ItemPointerEquals(&(tuple.t_self), &(SnapshotDirty->tid))))
1842 /* updated, so look at the updated copy */
1843 tuple.t_self = SnapshotDirty->tid;
1848 * Deleted or updated by this transaction; forget it.
1854 * For UPDATE/DELETE we have to return tid of actual row we're
1857 *tid = tuple.t_self;
1860 * Need to run a recheck subquery. Find or create a PQ stack entry.
1862 epq = estate->es_evalPlanQual;
1865 if (epq != NULL && epq->rti == 0)
1867 /* Top PQ stack entry is idle, so re-use it */
1868 Assert(!(estate->es_useEvalPlan) && epq->next == NULL);
1874 * If this is request for another RTE - Ra, - then we have to check
1875 * wasn't PlanQual requested for Ra already and if so then Ra' row was
1876 * updated again and we have to re-start old execution for Ra and
1877 * forget all what we done after Ra was suspended. Cool? -:))
1879 if (epq != NULL && epq->rti != rti &&
1880 epq->estate->es_evTuple[rti - 1] != NULL)
1884 evalPlanQual *oldepq;
1886 /* stop execution */
1887 EvalPlanQualStop(epq);
1888 /* pop previous PlanQual from the stack */
1890 Assert(oldepq && oldepq->rti != 0);
1891 /* push current PQ to freePQ stack */
1894 estate->es_evalPlanQual = epq;
1895 } while (epq->rti != rti);
1899 * If we are requested for another RTE then we have to suspend
1900 * execution of current PlanQual and start execution for new one.
1902 if (epq == NULL || epq->rti != rti)
1904 /* try to reuse plan used previously */
1905 evalPlanQual *newepq = (epq != NULL) ? epq->free : NULL;
1907 if (newepq == NULL) /* first call or freePQ stack is empty */
1909 newepq = (evalPlanQual *) palloc0(sizeof(evalPlanQual));
1910 newepq->free = NULL;
1911 newepq->estate = NULL;
1912 newepq->planstate = NULL;
1916 /* recycle previously used PlanQual */
1917 Assert(newepq->estate == NULL);
1920 /* push current PQ to the stack */
1923 estate->es_evalPlanQual = epq;
1928 Assert(epq->rti == rti);
1931 * Ok - we're requested for the same RTE. Unfortunately we still have
1932 * to end and restart execution of the plan, because ExecReScan
1933 * wouldn't ensure that upper plan nodes would reset themselves. We
1934 * could make that work if insertion of the target tuple were
1935 * integrated with the Param mechanism somehow, so that the upper plan
1936 * nodes know that their children's outputs have changed.
1938 * Note that the stack of free evalPlanQual nodes is quite useless at the
1939 * moment, since it only saves us from pallocing/releasing the
1940 * evalPlanQual nodes themselves. But it will be useful once we
1941 * implement ReScan instead of end/restart for re-using PlanQual
1946 /* stop execution */
1947 EvalPlanQualStop(epq);
1951 * Initialize new recheck query.
1953 * Note: if we were re-using PlanQual plans via ExecReScan, we'd need to
1954 * instead copy down changeable state from the top plan (including
1955 * es_result_relation_info, es_junkFilter) and reset locally
1956 * changeable state in the epq (including es_param_exec_vals,
1959 EvalPlanQualStart(epq, estate, epq->next);
1962 * free old RTE' tuple, if any, and store target tuple where
1963 * relation's scan node will see it
1965 epqstate = epq->estate;
1966 if (epqstate->es_evTuple[rti - 1] != NULL)
1967 heap_freetuple(epqstate->es_evTuple[rti - 1]);
1968 epqstate->es_evTuple[rti - 1] = copyTuple;
1970 return EvalPlanQualNext(estate);
1973 static TupleTableSlot *
1974 EvalPlanQualNext(EState *estate)
1976 evalPlanQual *epq = estate->es_evalPlanQual;
1977 MemoryContext oldcontext;
1978 TupleTableSlot *slot;
1980 Assert(epq->rti != 0);
1983 oldcontext = MemoryContextSwitchTo(epq->estate->es_query_cxt);
1984 slot = ExecProcNode(epq->planstate);
1985 MemoryContextSwitchTo(oldcontext);
1988 * No more tuples for this PQ. Continue previous one.
1990 if (TupIsNull(slot))
1992 evalPlanQual *oldepq;
1994 /* stop execution */
1995 EvalPlanQualStop(epq);
1996 /* pop old PQ from the stack */
2000 /* this is the first (oldest) PQ - mark as free */
2002 estate->es_useEvalPlan = false;
2003 /* and continue Query execution */
2006 Assert(oldepq->rti != 0);
2007 /* push current PQ to freePQ stack */
2010 estate->es_evalPlanQual = epq;
2018 EndEvalPlanQual(EState *estate)
2020 evalPlanQual *epq = estate->es_evalPlanQual;
2022 if (epq->rti == 0) /* plans already shutdowned */
2024 Assert(epq->next == NULL);
2030 evalPlanQual *oldepq;
2032 /* stop execution */
2033 EvalPlanQualStop(epq);
2034 /* pop old PQ from the stack */
2038 /* this is the first (oldest) PQ - mark as free */
2040 estate->es_useEvalPlan = false;
2043 Assert(oldepq->rti != 0);
2044 /* push current PQ to freePQ stack */
2047 estate->es_evalPlanQual = epq;
2052 * Start execution of one level of PlanQual.
2054 * This is a cut-down version of ExecutorStart(): we copy some state from
2055 * the top-level estate rather than initializing it fresh.
2058 EvalPlanQualStart(evalPlanQual *epq, EState *estate, evalPlanQual *priorepq)
2062 MemoryContext oldcontext;
2064 rtsize = list_length(estate->es_range_table);
2066 epq->estate = epqstate = CreateExecutorState();
2068 oldcontext = MemoryContextSwitchTo(epqstate->es_query_cxt);
2071 * The epqstates share the top query's copy of unchanging state such
2072 * as the snapshot, rangetable, result-rel info, and external Param
2073 * info. They need their own copies of local state, including a tuple
2074 * table, es_param_exec_vals, etc.
2076 epqstate->es_direction = ForwardScanDirection;
2077 epqstate->es_snapshot = estate->es_snapshot;
2078 epqstate->es_crosscheck_snapshot = estate->es_crosscheck_snapshot;
2079 epqstate->es_range_table = estate->es_range_table;
2080 epqstate->es_result_relations = estate->es_result_relations;
2081 epqstate->es_num_result_relations = estate->es_num_result_relations;
2082 epqstate->es_result_relation_info = estate->es_result_relation_info;
2083 epqstate->es_junkFilter = estate->es_junkFilter;
2084 epqstate->es_into_relation_descriptor = estate->es_into_relation_descriptor;
2085 epqstate->es_param_list_info = estate->es_param_list_info;
2086 if (estate->es_topPlan->nParamExec > 0)
2087 epqstate->es_param_exec_vals = (ParamExecData *)
2088 palloc0(estate->es_topPlan->nParamExec * sizeof(ParamExecData));
2089 epqstate->es_rowMark = estate->es_rowMark;
2090 epqstate->es_instrument = estate->es_instrument;
2091 epqstate->es_select_into = estate->es_select_into;
2092 epqstate->es_into_oids = estate->es_into_oids;
2093 epqstate->es_topPlan = estate->es_topPlan;
2096 * Each epqstate must have its own es_evTupleNull state, but all the
2097 * stack entries share es_evTuple state. This allows sub-rechecks to
2098 * inherit the value being examined by an outer recheck.
2100 epqstate->es_evTupleNull = (bool *) palloc0(rtsize * sizeof(bool));
2101 if (priorepq == NULL)
2102 /* first PQ stack entry */
2103 epqstate->es_evTuple = (HeapTuple *)
2104 palloc0(rtsize * sizeof(HeapTuple));
2106 /* later stack entries share the same storage */
2107 epqstate->es_evTuple = priorepq->estate->es_evTuple;
2109 epqstate->es_tupleTable =
2110 ExecCreateTupleTable(estate->es_tupleTable->size);
2112 epq->planstate = ExecInitNode(estate->es_topPlan, epqstate);
2114 MemoryContextSwitchTo(oldcontext);
2118 * End execution of one level of PlanQual.
2120 * This is a cut-down version of ExecutorEnd(); basically we want to do most
2121 * of the normal cleanup, but *not* close result relations (which we are
2122 * just sharing from the outer query).
2125 EvalPlanQualStop(evalPlanQual *epq)
2127 EState *epqstate = epq->estate;
2128 MemoryContext oldcontext;
2130 oldcontext = MemoryContextSwitchTo(epqstate->es_query_cxt);
2132 ExecEndNode(epq->planstate);
2134 ExecDropTupleTable(epqstate->es_tupleTable, true);
2135 epqstate->es_tupleTable = NULL;
2137 if (epqstate->es_evTuple[epq->rti - 1] != NULL)
2139 heap_freetuple(epqstate->es_evTuple[epq->rti - 1]);
2140 epqstate->es_evTuple[epq->rti - 1] = NULL;
2143 MemoryContextSwitchTo(oldcontext);
2145 FreeExecutorState(epqstate);
2148 epq->planstate = NULL;