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11 * The old ExecutorMain() has been replaced by ExecutorStart(),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) 1996-2007, PostgreSQL Global Development Group
25 * Portions Copyright (c) 1994, Regents of the University of California
29 * $PostgreSQL: pgsql/src/backend/executor/execMain.c,v 1.301 2007/11/30 21:22:54 tgl Exp $
31 *-------------------------------------------------------------------------
35 #include "access/heapam.h"
36 #include "access/reloptions.h"
37 #include "access/transam.h"
38 #include "access/xact.h"
39 #include "catalog/heap.h"
40 #include "catalog/namespace.h"
41 #include "catalog/toasting.h"
42 #include "commands/tablespace.h"
43 #include "commands/trigger.h"
44 #include "executor/execdebug.h"
45 #include "executor/instrument.h"
46 #include "executor/nodeSubplan.h"
47 #include "miscadmin.h"
48 #include "optimizer/clauses.h"
49 #include "parser/parse_clause.h"
50 #include "parser/parsetree.h"
51 #include "storage/smgr.h"
52 #include "utils/acl.h"
53 #include "utils/lsyscache.h"
54 #include "utils/memutils.h"
57 typedef struct evalPlanQual
62 struct evalPlanQual *next; /* stack of active PlanQual plans */
63 struct evalPlanQual *free; /* list of free PlanQual plans */
66 /* decls for local routines only used within this module */
67 static void InitPlan(QueryDesc *queryDesc, int eflags);
68 static void initResultRelInfo(ResultRelInfo *resultRelInfo,
69 Relation resultRelationDesc,
70 Index resultRelationIndex,
73 static void ExecEndPlan(PlanState *planstate, EState *estate);
74 static TupleTableSlot *ExecutePlan(EState *estate, PlanState *planstate,
77 ScanDirection direction,
79 static void ExecSelect(TupleTableSlot *slot,
80 DestReceiver *dest, EState *estate);
81 static void ExecInsert(TupleTableSlot *slot, ItemPointer tupleid,
82 TupleTableSlot *planSlot,
83 DestReceiver *dest, EState *estate);
84 static void ExecDelete(ItemPointer tupleid,
85 TupleTableSlot *planSlot,
86 DestReceiver *dest, EState *estate);
87 static void ExecUpdate(TupleTableSlot *slot, ItemPointer tupleid,
88 TupleTableSlot *planSlot,
89 DestReceiver *dest, EState *estate);
90 static void ExecProcessReturning(ProjectionInfo *projectReturning,
91 TupleTableSlot *tupleSlot,
92 TupleTableSlot *planSlot,
94 static TupleTableSlot *EvalPlanQualNext(EState *estate);
95 static void EndEvalPlanQual(EState *estate);
96 static void ExecCheckRTPerms(List *rangeTable);
97 static void ExecCheckRTEPerms(RangeTblEntry *rte);
98 static void ExecCheckXactReadOnly(PlannedStmt *plannedstmt);
99 static void EvalPlanQualStart(evalPlanQual *epq, EState *estate,
100 evalPlanQual *priorepq);
101 static void EvalPlanQualStop(evalPlanQual *epq);
102 static void OpenIntoRel(QueryDesc *queryDesc);
103 static void CloseIntoRel(QueryDesc *queryDesc);
104 static void intorel_startup(DestReceiver *self, int operation, TupleDesc typeinfo);
105 static void intorel_receive(TupleTableSlot *slot, DestReceiver *self);
106 static void intorel_shutdown(DestReceiver *self);
107 static void intorel_destroy(DestReceiver *self);
109 /* end of local decls */
112 /* ----------------------------------------------------------------
115 * This routine must be called at the beginning of any execution of any
118 * Takes a QueryDesc previously created by CreateQueryDesc (it's not real
119 * clear why we bother to separate the two functions, but...). The tupDesc
120 * field of the QueryDesc is filled in to describe the tuples that will be
121 * returned, and the internal fields (estate and planstate) are set up.
123 * eflags contains flag bits as described in executor.h.
125 * NB: the CurrentMemoryContext when this is called will become the parent
126 * of the per-query context used for this Executor invocation.
127 * ----------------------------------------------------------------
130 ExecutorStart(QueryDesc *queryDesc, int eflags)
133 MemoryContext oldcontext;
135 /* sanity checks: queryDesc must not be started already */
136 Assert(queryDesc != NULL);
137 Assert(queryDesc->estate == NULL);
140 * If the transaction is read-only, we need to check if any writes are
141 * planned to non-temporary tables. EXPLAIN is considered read-only.
143 if (XactReadOnly && !(eflags & EXEC_FLAG_EXPLAIN_ONLY))
144 ExecCheckXactReadOnly(queryDesc->plannedstmt);
147 * Build EState, switch into per-query memory context for startup.
149 estate = CreateExecutorState();
150 queryDesc->estate = estate;
152 oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
155 * Fill in parameters, if any, from queryDesc
157 estate->es_param_list_info = queryDesc->params;
159 if (queryDesc->plannedstmt->nParamExec > 0)
160 estate->es_param_exec_vals = (ParamExecData *)
161 palloc0(queryDesc->plannedstmt->nParamExec * sizeof(ParamExecData));
164 * If non-read-only query, set the command ID to mark output tuples with
166 switch (queryDesc->operation)
169 /* SELECT INTO and SELECT FOR UPDATE/SHARE need to mark tuples */
170 if (queryDesc->plannedstmt->intoClause != NULL ||
171 queryDesc->plannedstmt->rowMarks != NIL)
172 estate->es_output_cid = GetCurrentCommandId(true);
178 estate->es_output_cid = GetCurrentCommandId(true);
182 elog(ERROR, "unrecognized operation code: %d",
183 (int) queryDesc->operation);
188 * Copy other important information into the EState
190 estate->es_snapshot = queryDesc->snapshot;
191 estate->es_crosscheck_snapshot = queryDesc->crosscheck_snapshot;
192 estate->es_instrument = queryDesc->doInstrument;
195 * Initialize the plan state tree
197 InitPlan(queryDesc, eflags);
199 MemoryContextSwitchTo(oldcontext);
202 /* ----------------------------------------------------------------
205 * This is the main routine of the executor module. It accepts
206 * the query descriptor from the traffic cop and executes the
209 * ExecutorStart must have been called already.
211 * If direction is NoMovementScanDirection then nothing is done
212 * except to start up/shut down the destination. Otherwise,
213 * we retrieve up to 'count' tuples in the specified direction.
215 * Note: count = 0 is interpreted as no portal limit, i.e., run to
218 * ----------------------------------------------------------------
221 ExecutorRun(QueryDesc *queryDesc,
222 ScanDirection direction, long count)
228 TupleTableSlot *result;
229 MemoryContext oldcontext;
232 Assert(queryDesc != NULL);
234 estate = queryDesc->estate;
236 Assert(estate != NULL);
239 * Switch into per-query memory context
241 oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
244 * extract information from the query descriptor and the query feature.
246 operation = queryDesc->operation;
247 dest = queryDesc->dest;
250 * startup tuple receiver, if we will be emitting tuples
252 estate->es_processed = 0;
253 estate->es_lastoid = InvalidOid;
255 sendTuples = (operation == CMD_SELECT ||
256 queryDesc->plannedstmt->returningLists);
259 (*dest->rStartup) (dest, operation, queryDesc->tupDesc);
264 if (ScanDirectionIsNoMovement(direction))
267 result = ExecutePlan(estate,
268 queryDesc->planstate,
275 * shutdown tuple receiver, if we started it
278 (*dest->rShutdown) (dest);
280 MemoryContextSwitchTo(oldcontext);
285 /* ----------------------------------------------------------------
288 * This routine must be called at the end of execution of any
290 * ----------------------------------------------------------------
293 ExecutorEnd(QueryDesc *queryDesc)
296 MemoryContext oldcontext;
299 Assert(queryDesc != NULL);
301 estate = queryDesc->estate;
303 Assert(estate != NULL);
306 * Switch into per-query memory context to run ExecEndPlan
308 oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
310 ExecEndPlan(queryDesc->planstate, estate);
313 * Close the SELECT INTO relation if any
315 if (estate->es_select_into)
316 CloseIntoRel(queryDesc);
319 * Must switch out of context before destroying it
321 MemoryContextSwitchTo(oldcontext);
324 * Release EState and per-query memory context. This should release
325 * everything the executor has allocated.
327 FreeExecutorState(estate);
329 /* Reset queryDesc fields that no longer point to anything */
330 queryDesc->tupDesc = NULL;
331 queryDesc->estate = NULL;
332 queryDesc->planstate = NULL;
335 /* ----------------------------------------------------------------
338 * This routine may be called on an open queryDesc to rewind it
340 * ----------------------------------------------------------------
343 ExecutorRewind(QueryDesc *queryDesc)
346 MemoryContext oldcontext;
349 Assert(queryDesc != NULL);
351 estate = queryDesc->estate;
353 Assert(estate != NULL);
355 /* It's probably not sensible to rescan updating queries */
356 Assert(queryDesc->operation == CMD_SELECT);
359 * Switch into per-query memory context
361 oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
366 ExecReScan(queryDesc->planstate, NULL);
368 MemoryContextSwitchTo(oldcontext);
374 * Check access permissions for all relations listed in a range table.
377 ExecCheckRTPerms(List *rangeTable)
381 foreach(l, rangeTable)
383 ExecCheckRTEPerms((RangeTblEntry *) lfirst(l));
389 * Check access permissions for a single RTE.
392 ExecCheckRTEPerms(RangeTblEntry *rte)
394 AclMode requiredPerms;
399 * Only plain-relation RTEs need to be checked here. Function RTEs are
400 * checked by init_fcache when the function is prepared for execution.
401 * Join, subquery, and special RTEs need no checks.
403 if (rte->rtekind != RTE_RELATION)
407 * No work if requiredPerms is empty.
409 requiredPerms = rte->requiredPerms;
410 if (requiredPerms == 0)
416 * userid to check as: current user unless we have a setuid indication.
418 * Note: GetUserId() is presently fast enough that there's no harm in
419 * calling it separately for each RTE. If that stops being true, we could
420 * call it once in ExecCheckRTPerms and pass the userid down from there.
421 * But for now, no need for the extra clutter.
423 userid = rte->checkAsUser ? rte->checkAsUser : GetUserId();
426 * We must have *all* the requiredPerms bits, so use aclmask not aclcheck.
428 if (pg_class_aclmask(relOid, userid, requiredPerms, ACLMASK_ALL)
430 aclcheck_error(ACLCHECK_NO_PRIV, ACL_KIND_CLASS,
431 get_rel_name(relOid));
435 * Check that the query does not imply any writes to non-temp tables.
438 ExecCheckXactReadOnly(PlannedStmt *plannedstmt)
443 * CREATE TABLE AS or SELECT INTO?
445 * XXX should we allow this if the destination is temp?
447 if (plannedstmt->intoClause != NULL)
450 /* Fail if write permissions are requested on any non-temp table */
451 foreach(l, plannedstmt->rtable)
453 RangeTblEntry *rte = (RangeTblEntry *) lfirst(l);
455 if (rte->rtekind != RTE_RELATION)
458 if ((rte->requiredPerms & (~ACL_SELECT)) == 0)
461 if (isTempNamespace(get_rel_namespace(rte->relid)))
471 (errcode(ERRCODE_READ_ONLY_SQL_TRANSACTION),
472 errmsg("transaction is read-only")));
476 /* ----------------------------------------------------------------
479 * Initializes the query plan: open files, allocate storage
480 * and start up the rule manager
481 * ----------------------------------------------------------------
484 InitPlan(QueryDesc *queryDesc, int eflags)
486 CmdType operation = queryDesc->operation;
487 PlannedStmt *plannedstmt = queryDesc->plannedstmt;
488 Plan *plan = plannedstmt->planTree;
489 List *rangeTable = plannedstmt->rtable;
490 EState *estate = queryDesc->estate;
491 PlanState *planstate;
497 * Do permissions checks
499 ExecCheckRTPerms(rangeTable);
502 * initialize the node's execution state
504 estate->es_range_table = rangeTable;
507 * initialize result relation stuff
509 if (plannedstmt->resultRelations)
511 List *resultRelations = plannedstmt->resultRelations;
512 int numResultRelations = list_length(resultRelations);
513 ResultRelInfo *resultRelInfos;
514 ResultRelInfo *resultRelInfo;
516 resultRelInfos = (ResultRelInfo *)
517 palloc(numResultRelations * sizeof(ResultRelInfo));
518 resultRelInfo = resultRelInfos;
519 foreach(l, resultRelations)
521 Index resultRelationIndex = lfirst_int(l);
522 Oid resultRelationOid;
523 Relation resultRelation;
525 resultRelationOid = getrelid(resultRelationIndex, rangeTable);
526 resultRelation = heap_open(resultRelationOid, RowExclusiveLock);
527 initResultRelInfo(resultRelInfo,
531 estate->es_instrument);
534 estate->es_result_relations = resultRelInfos;
535 estate->es_num_result_relations = numResultRelations;
536 /* Initialize to first or only result rel */
537 estate->es_result_relation_info = resultRelInfos;
542 * if no result relation, then set state appropriately
544 estate->es_result_relations = NULL;
545 estate->es_num_result_relations = 0;
546 estate->es_result_relation_info = NULL;
550 * Detect whether we're doing SELECT INTO. If so, set the es_into_oids
551 * flag appropriately so that the plan tree will be initialized with the
552 * correct tuple descriptors. (Other SELECT INTO stuff comes later.)
554 estate->es_select_into = false;
555 if (operation == CMD_SELECT && plannedstmt->intoClause != NULL)
557 estate->es_select_into = true;
558 estate->es_into_oids = interpretOidsOption(plannedstmt->intoClause->options);
562 * Have to lock relations selected FOR UPDATE/FOR SHARE before we
563 * initialize the plan tree, else we'd be doing a lock upgrade. While we
564 * are at it, build the ExecRowMark list.
566 estate->es_rowMarks = NIL;
567 foreach(l, plannedstmt->rowMarks)
569 RowMarkClause *rc = (RowMarkClause *) lfirst(l);
570 Oid relid = getrelid(rc->rti, rangeTable);
574 relation = heap_open(relid, RowShareLock);
575 erm = (ExecRowMark *) palloc(sizeof(ExecRowMark));
576 erm->relation = relation;
578 erm->forUpdate = rc->forUpdate;
579 erm->noWait = rc->noWait;
580 /* We'll set up ctidAttno below */
581 erm->ctidAttNo = InvalidAttrNumber;
582 estate->es_rowMarks = lappend(estate->es_rowMarks, erm);
586 * Initialize the executor "tuple" table. We need slots for all the plan
587 * nodes, plus possibly output slots for the junkfilter(s). At this point
588 * we aren't sure if we need junkfilters, so just add slots for them
589 * unconditionally. Also, if it's not a SELECT, set up a slot for use for
590 * trigger output tuples. Also, one for RETURNING-list evaluation.
595 /* Slots for the main plan tree */
596 nSlots = ExecCountSlotsNode(plan);
597 /* Add slots for subplans and initplans */
598 foreach(l, plannedstmt->subplans)
600 Plan *subplan = (Plan *) lfirst(l);
602 nSlots += ExecCountSlotsNode(subplan);
604 /* Add slots for junkfilter(s) */
605 if (plannedstmt->resultRelations != NIL)
606 nSlots += list_length(plannedstmt->resultRelations);
609 if (operation != CMD_SELECT)
610 nSlots++; /* for es_trig_tuple_slot */
611 if (plannedstmt->returningLists)
612 nSlots++; /* for RETURNING projection */
614 estate->es_tupleTable = ExecCreateTupleTable(nSlots);
616 if (operation != CMD_SELECT)
617 estate->es_trig_tuple_slot =
618 ExecAllocTableSlot(estate->es_tupleTable);
621 /* mark EvalPlanQual not active */
622 estate->es_plannedstmt = plannedstmt;
623 estate->es_evalPlanQual = NULL;
624 estate->es_evTupleNull = NULL;
625 estate->es_evTuple = NULL;
626 estate->es_useEvalPlan = false;
629 * Initialize private state information for each SubPlan. We must do this
630 * before running ExecInitNode on the main query tree, since
631 * ExecInitSubPlan expects to be able to find these entries.
633 Assert(estate->es_subplanstates == NIL);
634 i = 1; /* subplan indices count from 1 */
635 foreach(l, plannedstmt->subplans)
637 Plan *subplan = (Plan *) lfirst(l);
638 PlanState *subplanstate;
642 * A subplan will never need to do BACKWARD scan nor MARK/RESTORE. If
643 * it is a parameterless subplan (not initplan), we suggest that it be
644 * prepared to handle REWIND efficiently; otherwise there is no need.
646 sp_eflags = eflags & EXEC_FLAG_EXPLAIN_ONLY;
647 if (bms_is_member(i, plannedstmt->rewindPlanIDs))
648 sp_eflags |= EXEC_FLAG_REWIND;
650 subplanstate = ExecInitNode(subplan, estate, sp_eflags);
652 estate->es_subplanstates = lappend(estate->es_subplanstates,
659 * Initialize the private state information for all the nodes in the query
660 * tree. This opens files, allocates storage and leaves us ready to start
663 planstate = ExecInitNode(plan, estate, eflags);
666 * Get the tuple descriptor describing the type of tuples to return. (this
667 * is especially important if we are creating a relation with "SELECT
670 tupType = ExecGetResultType(planstate);
673 * Initialize the junk filter if needed. SELECT and INSERT queries need a
674 * filter if there are any junk attrs in the tlist. INSERT and SELECT
675 * INTO also need a filter if the plan may return raw disk tuples (else
676 * heap_insert will be scribbling on the source relation!). UPDATE and
677 * DELETE always need a filter, since there's always a junk 'ctid'
678 * attribute present --- no need to look first.
681 bool junk_filter_needed = false;
688 foreach(tlist, plan->targetlist)
690 TargetEntry *tle = (TargetEntry *) lfirst(tlist);
694 junk_filter_needed = true;
698 if (!junk_filter_needed &&
699 (operation == CMD_INSERT || estate->es_select_into) &&
700 ExecMayReturnRawTuples(planstate))
701 junk_filter_needed = true;
705 junk_filter_needed = true;
711 if (junk_filter_needed)
714 * If there are multiple result relations, each one needs its own
715 * junk filter. Note this is only possible for UPDATE/DELETE, so
716 * we can't be fooled by some needing a filter and some not.
718 if (list_length(plannedstmt->resultRelations) > 1)
720 PlanState **appendplans;
722 ResultRelInfo *resultRelInfo;
724 /* Top plan had better be an Append here. */
725 Assert(IsA(plan, Append));
726 Assert(((Append *) plan)->isTarget);
727 Assert(IsA(planstate, AppendState));
728 appendplans = ((AppendState *) planstate)->appendplans;
729 as_nplans = ((AppendState *) planstate)->as_nplans;
730 Assert(as_nplans == estate->es_num_result_relations);
731 resultRelInfo = estate->es_result_relations;
732 for (i = 0; i < as_nplans; i++)
734 PlanState *subplan = appendplans[i];
737 j = ExecInitJunkFilter(subplan->plan->targetlist,
738 resultRelInfo->ri_RelationDesc->rd_att->tdhasoid,
739 ExecAllocTableSlot(estate->es_tupleTable));
742 * Since it must be UPDATE/DELETE, there had better be a
743 * "ctid" junk attribute in the tlist ... but ctid could
744 * be at a different resno for each result relation. We
745 * look up the ctid resnos now and save them in the
748 j->jf_junkAttNo = ExecFindJunkAttribute(j, "ctid");
749 if (!AttributeNumberIsValid(j->jf_junkAttNo))
750 elog(ERROR, "could not find junk ctid column");
751 resultRelInfo->ri_junkFilter = j;
756 * Set active junkfilter too; at this point ExecInitAppend has
757 * already selected an active result relation...
759 estate->es_junkFilter =
760 estate->es_result_relation_info->ri_junkFilter;
764 /* Normal case with just one JunkFilter */
767 j = ExecInitJunkFilter(planstate->plan->targetlist,
769 ExecAllocTableSlot(estate->es_tupleTable));
770 estate->es_junkFilter = j;
771 if (estate->es_result_relation_info)
772 estate->es_result_relation_info->ri_junkFilter = j;
774 if (operation == CMD_SELECT)
776 /* For SELECT, want to return the cleaned tuple type */
777 tupType = j->jf_cleanTupType;
778 /* For SELECT FOR UPDATE/SHARE, find the ctid attrs now */
779 foreach(l, estate->es_rowMarks)
781 ExecRowMark *erm = (ExecRowMark *) lfirst(l);
784 snprintf(resname, sizeof(resname), "ctid%u", erm->rti);
785 erm->ctidAttNo = ExecFindJunkAttribute(j, resname);
786 if (!AttributeNumberIsValid(erm->ctidAttNo))
787 elog(ERROR, "could not find junk \"%s\" column",
791 else if (operation == CMD_UPDATE || operation == CMD_DELETE)
793 /* For UPDATE/DELETE, find the ctid junk attr now */
794 j->jf_junkAttNo = ExecFindJunkAttribute(j, "ctid");
795 if (!AttributeNumberIsValid(j->jf_junkAttNo))
796 elog(ERROR, "could not find junk ctid column");
801 estate->es_junkFilter = NULL;
805 * Initialize RETURNING projections if needed.
807 if (plannedstmt->returningLists)
809 TupleTableSlot *slot;
810 ExprContext *econtext;
811 ResultRelInfo *resultRelInfo;
814 * We set QueryDesc.tupDesc to be the RETURNING rowtype in this case.
815 * We assume all the sublists will generate the same output tupdesc.
817 tupType = ExecTypeFromTL((List *) linitial(plannedstmt->returningLists),
820 /* Set up a slot for the output of the RETURNING projection(s) */
821 slot = ExecAllocTableSlot(estate->es_tupleTable);
822 ExecSetSlotDescriptor(slot, tupType);
823 /* Need an econtext too */
824 econtext = CreateExprContext(estate);
827 * Build a projection for each result rel. Note that any SubPlans in
828 * the RETURNING lists get attached to the topmost plan node.
830 Assert(list_length(plannedstmt->returningLists) == estate->es_num_result_relations);
831 resultRelInfo = estate->es_result_relations;
832 foreach(l, plannedstmt->returningLists)
834 List *rlist = (List *) lfirst(l);
837 rliststate = (List *) ExecInitExpr((Expr *) rlist, planstate);
838 resultRelInfo->ri_projectReturning =
839 ExecBuildProjectionInfo(rliststate, econtext, slot,
840 resultRelInfo->ri_RelationDesc->rd_att);
845 queryDesc->tupDesc = tupType;
846 queryDesc->planstate = planstate;
849 * If doing SELECT INTO, initialize the "into" relation. We must wait
850 * till now so we have the "clean" result tuple type to create the new
853 * If EXPLAIN, skip creating the "into" relation.
855 if (estate->es_select_into && !(eflags & EXEC_FLAG_EXPLAIN_ONLY))
856 OpenIntoRel(queryDesc);
860 * Initialize ResultRelInfo data for one result relation
863 initResultRelInfo(ResultRelInfo *resultRelInfo,
864 Relation resultRelationDesc,
865 Index resultRelationIndex,
870 * Check valid relkind ... parser and/or planner should have noticed this
871 * already, but let's make sure.
873 switch (resultRelationDesc->rd_rel->relkind)
875 case RELKIND_RELATION:
878 case RELKIND_SEQUENCE:
880 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
881 errmsg("cannot change sequence \"%s\"",
882 RelationGetRelationName(resultRelationDesc))));
884 case RELKIND_TOASTVALUE:
886 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
887 errmsg("cannot change TOAST relation \"%s\"",
888 RelationGetRelationName(resultRelationDesc))));
892 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
893 errmsg("cannot change view \"%s\"",
894 RelationGetRelationName(resultRelationDesc))));
898 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
899 errmsg("cannot change relation \"%s\"",
900 RelationGetRelationName(resultRelationDesc))));
904 /* OK, fill in the node */
905 MemSet(resultRelInfo, 0, sizeof(ResultRelInfo));
906 resultRelInfo->type = T_ResultRelInfo;
907 resultRelInfo->ri_RangeTableIndex = resultRelationIndex;
908 resultRelInfo->ri_RelationDesc = resultRelationDesc;
909 resultRelInfo->ri_NumIndices = 0;
910 resultRelInfo->ri_IndexRelationDescs = NULL;
911 resultRelInfo->ri_IndexRelationInfo = NULL;
912 /* make a copy so as not to depend on relcache info not changing... */
913 resultRelInfo->ri_TrigDesc = CopyTriggerDesc(resultRelationDesc->trigdesc);
914 if (resultRelInfo->ri_TrigDesc)
916 int n = resultRelInfo->ri_TrigDesc->numtriggers;
918 resultRelInfo->ri_TrigFunctions = (FmgrInfo *)
919 palloc0(n * sizeof(FmgrInfo));
921 resultRelInfo->ri_TrigInstrument = InstrAlloc(n);
923 resultRelInfo->ri_TrigInstrument = NULL;
927 resultRelInfo->ri_TrigFunctions = NULL;
928 resultRelInfo->ri_TrigInstrument = NULL;
930 resultRelInfo->ri_ConstraintExprs = NULL;
931 resultRelInfo->ri_junkFilter = NULL;
932 resultRelInfo->ri_projectReturning = NULL;
935 * If there are indices on the result relation, open them and save
936 * descriptors in the result relation info, so that we can add new index
937 * entries for the tuples we add/update. We need not do this for a
938 * DELETE, however, since deletion doesn't affect indexes.
940 if (resultRelationDesc->rd_rel->relhasindex &&
941 operation != CMD_DELETE)
942 ExecOpenIndices(resultRelInfo);
946 * ExecGetTriggerResultRel
948 * Get a ResultRelInfo for a trigger target relation. Most of the time,
949 * triggers are fired on one of the result relations of the query, and so
950 * we can just return a member of the es_result_relations array. (Note: in
951 * self-join situations there might be multiple members with the same OID;
952 * if so it doesn't matter which one we pick.) However, it is sometimes
953 * necessary to fire triggers on other relations; this happens mainly when an
954 * RI update trigger queues additional triggers on other relations, which will
955 * be processed in the context of the outer query. For efficiency's sake,
956 * we want to have a ResultRelInfo for those triggers too; that can avoid
957 * repeated re-opening of the relation. (It also provides a way for EXPLAIN
958 * ANALYZE to report the runtimes of such triggers.) So we make additional
959 * ResultRelInfo's as needed, and save them in es_trig_target_relations.
962 ExecGetTriggerResultRel(EState *estate, Oid relid)
964 ResultRelInfo *rInfo;
968 MemoryContext oldcontext;
970 /* First, search through the query result relations */
971 rInfo = estate->es_result_relations;
972 nr = estate->es_num_result_relations;
975 if (RelationGetRelid(rInfo->ri_RelationDesc) == relid)
980 /* Nope, but maybe we already made an extra ResultRelInfo for it */
981 foreach(l, estate->es_trig_target_relations)
983 rInfo = (ResultRelInfo *) lfirst(l);
984 if (RelationGetRelid(rInfo->ri_RelationDesc) == relid)
987 /* Nope, so we need a new one */
990 * Open the target relation's relcache entry. We assume that an
991 * appropriate lock is still held by the backend from whenever the trigger
992 * event got queued, so we need take no new lock here.
994 rel = heap_open(relid, NoLock);
997 * Make the new entry in the right context. Currently, we don't need any
998 * index information in ResultRelInfos used only for triggers, so tell
999 * initResultRelInfo it's a DELETE.
1001 oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
1002 rInfo = makeNode(ResultRelInfo);
1003 initResultRelInfo(rInfo,
1005 0, /* dummy rangetable index */
1007 estate->es_instrument);
1008 estate->es_trig_target_relations =
1009 lappend(estate->es_trig_target_relations, rInfo);
1010 MemoryContextSwitchTo(oldcontext);
1016 * ExecContextForcesOids
1018 * This is pretty grotty: when doing INSERT, UPDATE, or SELECT INTO,
1019 * we need to ensure that result tuples have space for an OID iff they are
1020 * going to be stored into a relation that has OIDs. In other contexts
1021 * we are free to choose whether to leave space for OIDs in result tuples
1022 * (we generally don't want to, but we do if a physical-tlist optimization
1023 * is possible). This routine checks the plan context and returns TRUE if the
1024 * choice is forced, FALSE if the choice is not forced. In the TRUE case,
1025 * *hasoids is set to the required value.
1027 * One reason this is ugly is that all plan nodes in the plan tree will emit
1028 * tuples with space for an OID, though we really only need the topmost node
1029 * to do so. However, node types like Sort don't project new tuples but just
1030 * return their inputs, and in those cases the requirement propagates down
1031 * to the input node. Eventually we might make this code smart enough to
1032 * recognize how far down the requirement really goes, but for now we just
1033 * make all plan nodes do the same thing if the top level forces the choice.
1035 * We assume that estate->es_result_relation_info is already set up to
1036 * describe the target relation. Note that in an UPDATE that spans an
1037 * inheritance tree, some of the target relations may have OIDs and some not.
1038 * We have to make the decisions on a per-relation basis as we initialize
1039 * each of the child plans of the topmost Append plan.
1041 * SELECT INTO is even uglier, because we don't have the INTO relation's
1042 * descriptor available when this code runs; we have to look aside at a
1043 * flag set by InitPlan().
1046 ExecContextForcesOids(PlanState *planstate, bool *hasoids)
1048 if (planstate->state->es_select_into)
1050 *hasoids = planstate->state->es_into_oids;
1055 ResultRelInfo *ri = planstate->state->es_result_relation_info;
1059 Relation rel = ri->ri_RelationDesc;
1063 *hasoids = rel->rd_rel->relhasoids;
1072 /* ----------------------------------------------------------------
1075 * Cleans up the query plan -- closes files and frees up storage
1077 * NOTE: we are no longer very worried about freeing storage per se
1078 * in this code; FreeExecutorState should be guaranteed to release all
1079 * memory that needs to be released. What we are worried about doing
1080 * is closing relations and dropping buffer pins. Thus, for example,
1081 * tuple tables must be cleared or dropped to ensure pins are released.
1082 * ----------------------------------------------------------------
1085 ExecEndPlan(PlanState *planstate, EState *estate)
1087 ResultRelInfo *resultRelInfo;
1092 * shut down any PlanQual processing we were doing
1094 if (estate->es_evalPlanQual != NULL)
1095 EndEvalPlanQual(estate);
1098 * shut down the node-type-specific query processing
1100 ExecEndNode(planstate);
1105 foreach(l, estate->es_subplanstates)
1107 PlanState *subplanstate = (PlanState *) lfirst(l);
1109 ExecEndNode(subplanstate);
1113 * destroy the executor "tuple" table.
1115 ExecDropTupleTable(estate->es_tupleTable, true);
1116 estate->es_tupleTable = NULL;
1119 * close the result relation(s) if any, but hold locks until xact commit.
1121 resultRelInfo = estate->es_result_relations;
1122 for (i = estate->es_num_result_relations; i > 0; i--)
1124 /* Close indices and then the relation itself */
1125 ExecCloseIndices(resultRelInfo);
1126 heap_close(resultRelInfo->ri_RelationDesc, NoLock);
1131 * likewise close any trigger target relations
1133 foreach(l, estate->es_trig_target_relations)
1135 resultRelInfo = (ResultRelInfo *) lfirst(l);
1136 /* Close indices and then the relation itself */
1137 ExecCloseIndices(resultRelInfo);
1138 heap_close(resultRelInfo->ri_RelationDesc, NoLock);
1142 * close any relations selected FOR UPDATE/FOR SHARE, again keeping locks
1144 foreach(l, estate->es_rowMarks)
1146 ExecRowMark *erm = lfirst(l);
1148 heap_close(erm->relation, NoLock);
1152 /* ----------------------------------------------------------------
1155 * processes the query plan to retrieve 'numberTuples' tuples in the
1156 * direction specified.
1158 * Retrieves all tuples if numberTuples is 0
1160 * result is either a slot containing the last tuple in the case
1161 * of a SELECT or NULL otherwise.
1163 * Note: the ctid attribute is a 'junk' attribute that is removed before the
1165 * ----------------------------------------------------------------
1167 static TupleTableSlot *
1168 ExecutePlan(EState *estate,
1169 PlanState *planstate,
1172 ScanDirection direction,
1175 JunkFilter *junkfilter;
1176 TupleTableSlot *planSlot;
1177 TupleTableSlot *slot;
1178 ItemPointer tupleid = NULL;
1179 ItemPointerData tuple_ctid;
1180 long current_tuple_count;
1181 TupleTableSlot *result;
1184 * initialize local variables
1186 current_tuple_count = 0;
1190 * Set the direction.
1192 estate->es_direction = direction;
1195 * Process BEFORE EACH STATEMENT triggers
1200 ExecBSUpdateTriggers(estate, estate->es_result_relation_info);
1203 ExecBSDeleteTriggers(estate, estate->es_result_relation_info);
1206 ExecBSInsertTriggers(estate, estate->es_result_relation_info);
1214 * Loop until we've processed the proper number of tuples from the plan.
1219 /* Reset the per-output-tuple exprcontext */
1220 ResetPerTupleExprContext(estate);
1223 * Execute the plan and obtain a tuple
1226 if (estate->es_useEvalPlan)
1228 planSlot = EvalPlanQualNext(estate);
1229 if (TupIsNull(planSlot))
1230 planSlot = ExecProcNode(planstate);
1233 planSlot = ExecProcNode(planstate);
1236 * if the tuple is null, then we assume there is nothing more to
1237 * process so we just return null...
1239 if (TupIsNull(planSlot))
1247 * if we have a junk filter, then project a new tuple with the junk
1250 * Store this new "clean" tuple in the junkfilter's resultSlot.
1251 * (Formerly, we stored it back over the "dirty" tuple, which is WRONG
1252 * because that tuple slot has the wrong descriptor.)
1254 * Also, extract all the junk information we need.
1256 if ((junkfilter = estate->es_junkFilter) != NULL)
1262 * extract the 'ctid' junk attribute.
1264 if (operation == CMD_UPDATE || operation == CMD_DELETE)
1266 datum = ExecGetJunkAttribute(slot, junkfilter->jf_junkAttNo,
1268 /* shouldn't ever get a null result... */
1270 elog(ERROR, "ctid is NULL");
1272 tupleid = (ItemPointer) DatumGetPointer(datum);
1273 tuple_ctid = *tupleid; /* make sure we don't free the ctid!! */
1274 tupleid = &tuple_ctid;
1278 * Process any FOR UPDATE or FOR SHARE locking requested.
1280 else if (estate->es_rowMarks != NIL)
1285 foreach(l, estate->es_rowMarks)
1287 ExecRowMark *erm = lfirst(l);
1288 HeapTupleData tuple;
1290 ItemPointerData update_ctid;
1291 TransactionId update_xmax;
1292 TupleTableSlot *newSlot;
1293 LockTupleMode lockmode;
1296 datum = ExecGetJunkAttribute(slot,
1299 /* shouldn't ever get a null result... */
1301 elog(ERROR, "ctid is NULL");
1303 tuple.t_self = *((ItemPointer) DatumGetPointer(datum));
1306 lockmode = LockTupleExclusive;
1308 lockmode = LockTupleShared;
1310 test = heap_lock_tuple(erm->relation, &tuple, &buffer,
1311 &update_ctid, &update_xmax,
1312 estate->es_output_cid,
1313 lockmode, erm->noWait);
1314 ReleaseBuffer(buffer);
1317 case HeapTupleSelfUpdated:
1318 /* treat it as deleted; do not process */
1321 case HeapTupleMayBeUpdated:
1324 case HeapTupleUpdated:
1325 if (IsXactIsoLevelSerializable)
1327 (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
1328 errmsg("could not serialize access due to concurrent update")));
1329 if (!ItemPointerEquals(&update_ctid,
1332 /* updated, so look at updated version */
1333 newSlot = EvalPlanQual(estate,
1337 if (!TupIsNull(newSlot))
1339 slot = planSlot = newSlot;
1340 estate->es_useEvalPlan = true;
1346 * if tuple was deleted or PlanQual failed for
1347 * updated tuple - we must not return this tuple!
1352 elog(ERROR, "unrecognized heap_lock_tuple status: %u",
1360 * Create a new "clean" tuple with all junk attributes removed. We
1361 * don't need to do this for DELETE, however (there will in fact
1362 * be no non-junk attributes in a DELETE!)
1364 if (operation != CMD_DELETE)
1365 slot = ExecFilterJunk(junkfilter, slot);
1369 * now that we have a tuple, do the appropriate thing with it.. either
1370 * return it to the user, add it to a relation someplace, delete it
1371 * from a relation, or modify some of its attributes.
1376 ExecSelect(slot, dest, estate);
1381 ExecInsert(slot, tupleid, planSlot, dest, estate);
1386 ExecDelete(tupleid, planSlot, dest, estate);
1391 ExecUpdate(slot, tupleid, planSlot, dest, estate);
1396 elog(ERROR, "unrecognized operation code: %d",
1403 * check our tuple count.. if we've processed the proper number then
1404 * quit, else loop again and process more tuples. Zero numberTuples
1407 current_tuple_count++;
1408 if (numberTuples && numberTuples == current_tuple_count)
1413 * Process AFTER EACH STATEMENT triggers
1418 ExecASUpdateTriggers(estate, estate->es_result_relation_info);
1421 ExecASDeleteTriggers(estate, estate->es_result_relation_info);
1424 ExecASInsertTriggers(estate, estate->es_result_relation_info);
1432 * here, result is either a slot containing a tuple in the case of a
1433 * SELECT or NULL otherwise.
1438 /* ----------------------------------------------------------------
1441 * SELECTs are easy.. we just pass the tuple to the appropriate
1443 * ----------------------------------------------------------------
1446 ExecSelect(TupleTableSlot *slot,
1450 (*dest->receiveSlot) (slot, dest);
1452 (estate->es_processed)++;
1455 /* ----------------------------------------------------------------
1458 * INSERTs are trickier.. we have to insert the tuple into
1459 * the base relation and insert appropriate tuples into the
1461 * ----------------------------------------------------------------
1464 ExecInsert(TupleTableSlot *slot,
1465 ItemPointer tupleid,
1466 TupleTableSlot *planSlot,
1471 ResultRelInfo *resultRelInfo;
1472 Relation resultRelationDesc;
1476 * get the heap tuple out of the tuple table slot, making sure we have a
1479 tuple = ExecMaterializeSlot(slot);
1482 * get information on the (current) result relation
1484 resultRelInfo = estate->es_result_relation_info;
1485 resultRelationDesc = resultRelInfo->ri_RelationDesc;
1487 /* BEFORE ROW INSERT Triggers */
1488 if (resultRelInfo->ri_TrigDesc &&
1489 resultRelInfo->ri_TrigDesc->n_before_row[TRIGGER_EVENT_INSERT] > 0)
1493 newtuple = ExecBRInsertTriggers(estate, resultRelInfo, tuple);
1495 if (newtuple == NULL) /* "do nothing" */
1498 if (newtuple != tuple) /* modified by Trigger(s) */
1501 * Put the modified tuple into a slot for convenience of routines
1502 * below. We assume the tuple was allocated in per-tuple memory
1503 * context, and therefore will go away by itself. The tuple table
1504 * slot should not try to clear it.
1506 TupleTableSlot *newslot = estate->es_trig_tuple_slot;
1508 if (newslot->tts_tupleDescriptor != slot->tts_tupleDescriptor)
1509 ExecSetSlotDescriptor(newslot, slot->tts_tupleDescriptor);
1510 ExecStoreTuple(newtuple, newslot, InvalidBuffer, false);
1517 * Check the constraints of the tuple
1519 if (resultRelationDesc->rd_att->constr)
1520 ExecConstraints(resultRelInfo, slot, estate);
1525 * Note: heap_insert returns the tid (location) of the new tuple in the
1528 newId = heap_insert(resultRelationDesc, tuple,
1529 estate->es_output_cid,
1533 (estate->es_processed)++;
1534 estate->es_lastoid = newId;
1535 setLastTid(&(tuple->t_self));
1538 * insert index entries for tuple
1540 if (resultRelInfo->ri_NumIndices > 0)
1541 ExecInsertIndexTuples(slot, &(tuple->t_self), estate, false);
1543 /* AFTER ROW INSERT Triggers */
1544 ExecARInsertTriggers(estate, resultRelInfo, tuple);
1546 /* Process RETURNING if present */
1547 if (resultRelInfo->ri_projectReturning)
1548 ExecProcessReturning(resultRelInfo->ri_projectReturning,
1549 slot, planSlot, dest);
1552 /* ----------------------------------------------------------------
1555 * DELETE is like UPDATE, except that we delete the tuple and no
1556 * index modifications are needed
1557 * ----------------------------------------------------------------
1560 ExecDelete(ItemPointer tupleid,
1561 TupleTableSlot *planSlot,
1565 ResultRelInfo *resultRelInfo;
1566 Relation resultRelationDesc;
1568 ItemPointerData update_ctid;
1569 TransactionId update_xmax;
1572 * get information on the (current) result relation
1574 resultRelInfo = estate->es_result_relation_info;
1575 resultRelationDesc = resultRelInfo->ri_RelationDesc;
1577 /* BEFORE ROW DELETE Triggers */
1578 if (resultRelInfo->ri_TrigDesc &&
1579 resultRelInfo->ri_TrigDesc->n_before_row[TRIGGER_EVENT_DELETE] > 0)
1583 dodelete = ExecBRDeleteTriggers(estate, resultRelInfo, tupleid);
1585 if (!dodelete) /* "do nothing" */
1592 * Note: if es_crosscheck_snapshot isn't InvalidSnapshot, we check that
1593 * the row to be deleted is visible to that snapshot, and throw a can't-
1594 * serialize error if not. This is a special-case behavior needed for
1595 * referential integrity updates in serializable transactions.
1598 result = heap_delete(resultRelationDesc, tupleid,
1599 &update_ctid, &update_xmax,
1600 estate->es_output_cid,
1601 estate->es_crosscheck_snapshot,
1602 true /* wait for commit */ );
1605 case HeapTupleSelfUpdated:
1606 /* already deleted by self; nothing to do */
1609 case HeapTupleMayBeUpdated:
1612 case HeapTupleUpdated:
1613 if (IsXactIsoLevelSerializable)
1615 (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
1616 errmsg("could not serialize access due to concurrent update")));
1617 else if (!ItemPointerEquals(tupleid, &update_ctid))
1619 TupleTableSlot *epqslot;
1621 epqslot = EvalPlanQual(estate,
1622 resultRelInfo->ri_RangeTableIndex,
1625 if (!TupIsNull(epqslot))
1627 *tupleid = update_ctid;
1631 /* tuple already deleted; nothing to do */
1635 elog(ERROR, "unrecognized heap_delete status: %u", result);
1640 (estate->es_processed)++;
1643 * Note: Normally one would think that we have to delete index tuples
1644 * associated with the heap tuple now...
1646 * ... but in POSTGRES, we have no need to do this because VACUUM will
1647 * take care of it later. We can't delete index tuples immediately
1648 * anyway, since the tuple is still visible to other transactions.
1651 /* AFTER ROW DELETE Triggers */
1652 ExecARDeleteTriggers(estate, resultRelInfo, tupleid);
1654 /* Process RETURNING if present */
1655 if (resultRelInfo->ri_projectReturning)
1658 * We have to put the target tuple into a slot, which means first we
1659 * gotta fetch it. We can use the trigger tuple slot.
1661 TupleTableSlot *slot = estate->es_trig_tuple_slot;
1662 HeapTupleData deltuple;
1665 deltuple.t_self = *tupleid;
1666 if (!heap_fetch(resultRelationDesc, SnapshotAny,
1667 &deltuple, &delbuffer, false, NULL))
1668 elog(ERROR, "failed to fetch deleted tuple for DELETE RETURNING");
1670 if (slot->tts_tupleDescriptor != RelationGetDescr(resultRelationDesc))
1671 ExecSetSlotDescriptor(slot, RelationGetDescr(resultRelationDesc));
1672 ExecStoreTuple(&deltuple, slot, InvalidBuffer, false);
1674 ExecProcessReturning(resultRelInfo->ri_projectReturning,
1675 slot, planSlot, dest);
1677 ExecClearTuple(slot);
1678 ReleaseBuffer(delbuffer);
1682 /* ----------------------------------------------------------------
1685 * note: we can't run UPDATE queries with transactions
1686 * off because UPDATEs are actually INSERTs and our
1687 * scan will mistakenly loop forever, updating the tuple
1688 * it just inserted.. This should be fixed but until it
1689 * is, we don't want to get stuck in an infinite loop
1690 * which corrupts your database..
1691 * ----------------------------------------------------------------
1694 ExecUpdate(TupleTableSlot *slot,
1695 ItemPointer tupleid,
1696 TupleTableSlot *planSlot,
1701 ResultRelInfo *resultRelInfo;
1702 Relation resultRelationDesc;
1704 ItemPointerData update_ctid;
1705 TransactionId update_xmax;
1708 * abort the operation if not running transactions
1710 if (IsBootstrapProcessingMode())
1711 elog(ERROR, "cannot UPDATE during bootstrap");
1714 * get the heap tuple out of the tuple table slot, making sure we have a
1717 tuple = ExecMaterializeSlot(slot);
1720 * get information on the (current) result relation
1722 resultRelInfo = estate->es_result_relation_info;
1723 resultRelationDesc = resultRelInfo->ri_RelationDesc;
1725 /* BEFORE ROW UPDATE Triggers */
1726 if (resultRelInfo->ri_TrigDesc &&
1727 resultRelInfo->ri_TrigDesc->n_before_row[TRIGGER_EVENT_UPDATE] > 0)
1731 newtuple = ExecBRUpdateTriggers(estate, resultRelInfo,
1734 if (newtuple == NULL) /* "do nothing" */
1737 if (newtuple != tuple) /* modified by Trigger(s) */
1740 * Put the modified tuple into a slot for convenience of routines
1741 * below. We assume the tuple was allocated in per-tuple memory
1742 * context, and therefore will go away by itself. The tuple table
1743 * slot should not try to clear it.
1745 TupleTableSlot *newslot = estate->es_trig_tuple_slot;
1747 if (newslot->tts_tupleDescriptor != slot->tts_tupleDescriptor)
1748 ExecSetSlotDescriptor(newslot, slot->tts_tupleDescriptor);
1749 ExecStoreTuple(newtuple, newslot, InvalidBuffer, false);
1756 * Check the constraints of the tuple
1758 * If we generate a new candidate tuple after EvalPlanQual testing, we
1759 * must loop back here and recheck constraints. (We don't need to redo
1760 * triggers, however. If there are any BEFORE triggers then trigger.c
1761 * will have done heap_lock_tuple to lock the correct tuple, so there's no
1762 * need to do them again.)
1765 if (resultRelationDesc->rd_att->constr)
1766 ExecConstraints(resultRelInfo, slot, estate);
1769 * replace the heap tuple
1771 * Note: if es_crosscheck_snapshot isn't InvalidSnapshot, we check that
1772 * the row to be updated is visible to that snapshot, and throw a can't-
1773 * serialize error if not. This is a special-case behavior needed for
1774 * referential integrity updates in serializable transactions.
1776 result = heap_update(resultRelationDesc, tupleid, tuple,
1777 &update_ctid, &update_xmax,
1778 estate->es_output_cid,
1779 estate->es_crosscheck_snapshot,
1780 true /* wait for commit */ );
1783 case HeapTupleSelfUpdated:
1784 /* already deleted by self; nothing to do */
1787 case HeapTupleMayBeUpdated:
1790 case HeapTupleUpdated:
1791 if (IsXactIsoLevelSerializable)
1793 (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
1794 errmsg("could not serialize access due to concurrent update")));
1795 else if (!ItemPointerEquals(tupleid, &update_ctid))
1797 TupleTableSlot *epqslot;
1799 epqslot = EvalPlanQual(estate,
1800 resultRelInfo->ri_RangeTableIndex,
1803 if (!TupIsNull(epqslot))
1805 *tupleid = update_ctid;
1806 slot = ExecFilterJunk(estate->es_junkFilter, epqslot);
1807 tuple = ExecMaterializeSlot(slot);
1811 /* tuple already deleted; nothing to do */
1815 elog(ERROR, "unrecognized heap_update status: %u", result);
1820 (estate->es_processed)++;
1823 * Note: instead of having to update the old index tuples associated with
1824 * the heap tuple, all we do is form and insert new index tuples. This is
1825 * because UPDATEs are actually DELETEs and INSERTs, and index tuple
1826 * deletion is done later by VACUUM (see notes in ExecDelete). All we do
1827 * here is insert new index tuples. -cim 9/27/89
1831 * insert index entries for tuple
1833 * Note: heap_update returns the tid (location) of the new tuple in the
1836 * If it's a HOT update, we mustn't insert new index entries.
1838 if (resultRelInfo->ri_NumIndices > 0 && !HeapTupleIsHeapOnly(tuple))
1839 ExecInsertIndexTuples(slot, &(tuple->t_self), estate, false);
1841 /* AFTER ROW UPDATE Triggers */
1842 ExecARUpdateTriggers(estate, resultRelInfo, tupleid, tuple);
1844 /* Process RETURNING if present */
1845 if (resultRelInfo->ri_projectReturning)
1846 ExecProcessReturning(resultRelInfo->ri_projectReturning,
1847 slot, planSlot, dest);
1851 * ExecRelCheck --- check that tuple meets constraints for result relation
1854 ExecRelCheck(ResultRelInfo *resultRelInfo,
1855 TupleTableSlot *slot, EState *estate)
1857 Relation rel = resultRelInfo->ri_RelationDesc;
1858 int ncheck = rel->rd_att->constr->num_check;
1859 ConstrCheck *check = rel->rd_att->constr->check;
1860 ExprContext *econtext;
1861 MemoryContext oldContext;
1866 * If first time through for this result relation, build expression
1867 * nodetrees for rel's constraint expressions. Keep them in the per-query
1868 * memory context so they'll survive throughout the query.
1870 if (resultRelInfo->ri_ConstraintExprs == NULL)
1872 oldContext = MemoryContextSwitchTo(estate->es_query_cxt);
1873 resultRelInfo->ri_ConstraintExprs =
1874 (List **) palloc(ncheck * sizeof(List *));
1875 for (i = 0; i < ncheck; i++)
1877 /* ExecQual wants implicit-AND form */
1878 qual = make_ands_implicit(stringToNode(check[i].ccbin));
1879 resultRelInfo->ri_ConstraintExprs[i] = (List *)
1880 ExecPrepareExpr((Expr *) qual, estate);
1882 MemoryContextSwitchTo(oldContext);
1886 * We will use the EState's per-tuple context for evaluating constraint
1887 * expressions (creating it if it's not already there).
1889 econtext = GetPerTupleExprContext(estate);
1891 /* Arrange for econtext's scan tuple to be the tuple under test */
1892 econtext->ecxt_scantuple = slot;
1894 /* And evaluate the constraints */
1895 for (i = 0; i < ncheck; i++)
1897 qual = resultRelInfo->ri_ConstraintExprs[i];
1900 * NOTE: SQL92 specifies that a NULL result from a constraint
1901 * expression is not to be treated as a failure. Therefore, tell
1902 * ExecQual to return TRUE for NULL.
1904 if (!ExecQual(qual, econtext, true))
1905 return check[i].ccname;
1908 /* NULL result means no error */
1913 ExecConstraints(ResultRelInfo *resultRelInfo,
1914 TupleTableSlot *slot, EState *estate)
1916 Relation rel = resultRelInfo->ri_RelationDesc;
1917 TupleConstr *constr = rel->rd_att->constr;
1921 if (constr->has_not_null)
1923 int natts = rel->rd_att->natts;
1926 for (attrChk = 1; attrChk <= natts; attrChk++)
1928 if (rel->rd_att->attrs[attrChk - 1]->attnotnull &&
1929 slot_attisnull(slot, attrChk))
1931 (errcode(ERRCODE_NOT_NULL_VIOLATION),
1932 errmsg("null value in column \"%s\" violates not-null constraint",
1933 NameStr(rel->rd_att->attrs[attrChk - 1]->attname))));
1937 if (constr->num_check > 0)
1941 if ((failed = ExecRelCheck(resultRelInfo, slot, estate)) != NULL)
1943 (errcode(ERRCODE_CHECK_VIOLATION),
1944 errmsg("new row for relation \"%s\" violates check constraint \"%s\"",
1945 RelationGetRelationName(rel), failed)));
1950 * ExecProcessReturning --- evaluate a RETURNING list and send to dest
1952 * projectReturning: RETURNING projection info for current result rel
1953 * tupleSlot: slot holding tuple actually inserted/updated/deleted
1954 * planSlot: slot holding tuple returned by top plan node
1955 * dest: where to send the output
1958 ExecProcessReturning(ProjectionInfo *projectReturning,
1959 TupleTableSlot *tupleSlot,
1960 TupleTableSlot *planSlot,
1963 ExprContext *econtext = projectReturning->pi_exprContext;
1964 TupleTableSlot *retSlot;
1967 * Reset per-tuple memory context to free any expression evaluation
1968 * storage allocated in the previous cycle.
1970 ResetExprContext(econtext);
1972 /* Make tuple and any needed join variables available to ExecProject */
1973 econtext->ecxt_scantuple = tupleSlot;
1974 econtext->ecxt_outertuple = planSlot;
1976 /* Compute the RETURNING expressions */
1977 retSlot = ExecProject(projectReturning, NULL);
1980 (*dest->receiveSlot) (retSlot, dest);
1982 ExecClearTuple(retSlot);
1986 * Check a modified tuple to see if we want to process its updated version
1987 * under READ COMMITTED rules.
1989 * See backend/executor/README for some info about how this works.
1991 * estate - executor state data
1992 * rti - rangetable index of table containing tuple
1993 * *tid - t_ctid from the outdated tuple (ie, next updated version)
1994 * priorXmax - t_xmax from the outdated tuple
1996 * *tid is also an output parameter: it's modified to hold the TID of the
1997 * latest version of the tuple (note this may be changed even on failure)
1999 * Returns a slot containing the new candidate update/delete tuple, or
2000 * NULL if we determine we shouldn't process the row.
2003 EvalPlanQual(EState *estate, Index rti,
2004 ItemPointer tid, TransactionId priorXmax)
2009 HeapTupleData tuple;
2010 HeapTuple copyTuple = NULL;
2011 SnapshotData SnapshotDirty;
2017 * find relation containing target tuple
2019 if (estate->es_result_relation_info != NULL &&
2020 estate->es_result_relation_info->ri_RangeTableIndex == rti)
2021 relation = estate->es_result_relation_info->ri_RelationDesc;
2027 foreach(l, estate->es_rowMarks)
2029 if (((ExecRowMark *) lfirst(l))->rti == rti)
2031 relation = ((ExecRowMark *) lfirst(l))->relation;
2035 if (relation == NULL)
2036 elog(ERROR, "could not find RowMark for RT index %u", rti);
2042 * Loop here to deal with updated or busy tuples
2044 InitDirtySnapshot(SnapshotDirty);
2045 tuple.t_self = *tid;
2050 if (heap_fetch(relation, &SnapshotDirty, &tuple, &buffer, true, NULL))
2053 * If xmin isn't what we're expecting, the slot must have been
2054 * recycled and reused for an unrelated tuple. This implies that
2055 * the latest version of the row was deleted, so we need do
2056 * nothing. (Should be safe to examine xmin without getting
2057 * buffer's content lock, since xmin never changes in an existing
2060 if (!TransactionIdEquals(HeapTupleHeaderGetXmin(tuple.t_data),
2063 ReleaseBuffer(buffer);
2067 /* otherwise xmin should not be dirty... */
2068 if (TransactionIdIsValid(SnapshotDirty.xmin))
2069 elog(ERROR, "t_xmin is uncommitted in tuple to be updated");
2072 * If tuple is being updated by other transaction then we have to
2073 * wait for its commit/abort.
2075 if (TransactionIdIsValid(SnapshotDirty.xmax))
2077 ReleaseBuffer(buffer);
2078 XactLockTableWait(SnapshotDirty.xmax);
2079 continue; /* loop back to repeat heap_fetch */
2083 * If tuple was inserted by our own transaction, we have to check
2084 * cmin against es_output_cid: cmin >= current CID means our
2085 * command cannot see the tuple, so we should ignore it. Without
2086 * this we are open to the "Halloween problem" of indefinitely
2087 * re-updating the same tuple. (We need not check cmax because
2088 * HeapTupleSatisfiesDirty will consider a tuple deleted by our
2089 * transaction dead, regardless of cmax.) We just checked that
2090 * priorXmax == xmin, so we can test that variable instead of
2091 * doing HeapTupleHeaderGetXmin again.
2093 if (TransactionIdIsCurrentTransactionId(priorXmax) &&
2094 HeapTupleHeaderGetCmin(tuple.t_data) >= estate->es_output_cid)
2096 ReleaseBuffer(buffer);
2101 * We got tuple - now copy it for use by recheck query.
2103 copyTuple = heap_copytuple(&tuple);
2104 ReleaseBuffer(buffer);
2109 * If the referenced slot was actually empty, the latest version of
2110 * the row must have been deleted, so we need do nothing.
2112 if (tuple.t_data == NULL)
2114 ReleaseBuffer(buffer);
2119 * As above, if xmin isn't what we're expecting, do nothing.
2121 if (!TransactionIdEquals(HeapTupleHeaderGetXmin(tuple.t_data),
2124 ReleaseBuffer(buffer);
2129 * If we get here, the tuple was found but failed SnapshotDirty.
2130 * Assuming the xmin is either a committed xact or our own xact (as it
2131 * certainly should be if we're trying to modify the tuple), this must
2132 * mean that the row was updated or deleted by either a committed xact
2133 * or our own xact. If it was deleted, we can ignore it; if it was
2134 * updated then chain up to the next version and repeat the whole
2137 * As above, it should be safe to examine xmax and t_ctid without the
2138 * buffer content lock, because they can't be changing.
2140 if (ItemPointerEquals(&tuple.t_self, &tuple.t_data->t_ctid))
2142 /* deleted, so forget about it */
2143 ReleaseBuffer(buffer);
2147 /* updated, so look at the updated row */
2148 tuple.t_self = tuple.t_data->t_ctid;
2149 /* updated row should have xmin matching this xmax */
2150 priorXmax = HeapTupleHeaderGetXmax(tuple.t_data);
2151 ReleaseBuffer(buffer);
2152 /* loop back to fetch next in chain */
2156 * For UPDATE/DELETE we have to return tid of actual row we're executing
2159 *tid = tuple.t_self;
2162 * Need to run a recheck subquery. Find or create a PQ stack entry.
2164 epq = estate->es_evalPlanQual;
2167 if (epq != NULL && epq->rti == 0)
2169 /* Top PQ stack entry is idle, so re-use it */
2170 Assert(!(estate->es_useEvalPlan) && epq->next == NULL);
2176 * If this is request for another RTE - Ra, - then we have to check wasn't
2177 * PlanQual requested for Ra already and if so then Ra' row was updated
2178 * again and we have to re-start old execution for Ra and forget all what
2179 * we done after Ra was suspended. Cool? -:))
2181 if (epq != NULL && epq->rti != rti &&
2182 epq->estate->es_evTuple[rti - 1] != NULL)
2186 evalPlanQual *oldepq;
2188 /* stop execution */
2189 EvalPlanQualStop(epq);
2190 /* pop previous PlanQual from the stack */
2192 Assert(oldepq && oldepq->rti != 0);
2193 /* push current PQ to freePQ stack */
2196 estate->es_evalPlanQual = epq;
2197 } while (epq->rti != rti);
2201 * If we are requested for another RTE then we have to suspend execution
2202 * of current PlanQual and start execution for new one.
2204 if (epq == NULL || epq->rti != rti)
2206 /* try to reuse plan used previously */
2207 evalPlanQual *newepq = (epq != NULL) ? epq->free : NULL;
2209 if (newepq == NULL) /* first call or freePQ stack is empty */
2211 newepq = (evalPlanQual *) palloc0(sizeof(evalPlanQual));
2212 newepq->free = NULL;
2213 newepq->estate = NULL;
2214 newepq->planstate = NULL;
2218 /* recycle previously used PlanQual */
2219 Assert(newepq->estate == NULL);
2222 /* push current PQ to the stack */
2225 estate->es_evalPlanQual = epq;
2230 Assert(epq->rti == rti);
2233 * Ok - we're requested for the same RTE. Unfortunately we still have to
2234 * end and restart execution of the plan, because ExecReScan wouldn't
2235 * ensure that upper plan nodes would reset themselves. We could make
2236 * that work if insertion of the target tuple were integrated with the
2237 * Param mechanism somehow, so that the upper plan nodes know that their
2238 * children's outputs have changed.
2240 * Note that the stack of free evalPlanQual nodes is quite useless at the
2241 * moment, since it only saves us from pallocing/releasing the
2242 * evalPlanQual nodes themselves. But it will be useful once we implement
2243 * ReScan instead of end/restart for re-using PlanQual nodes.
2247 /* stop execution */
2248 EvalPlanQualStop(epq);
2252 * Initialize new recheck query.
2254 * Note: if we were re-using PlanQual plans via ExecReScan, we'd need to
2255 * instead copy down changeable state from the top plan (including
2256 * es_result_relation_info, es_junkFilter) and reset locally changeable
2257 * state in the epq (including es_param_exec_vals, es_evTupleNull).
2259 EvalPlanQualStart(epq, estate, epq->next);
2262 * free old RTE' tuple, if any, and store target tuple where relation's
2263 * scan node will see it
2265 epqstate = epq->estate;
2266 if (epqstate->es_evTuple[rti - 1] != NULL)
2267 heap_freetuple(epqstate->es_evTuple[rti - 1]);
2268 epqstate->es_evTuple[rti - 1] = copyTuple;
2270 return EvalPlanQualNext(estate);
2273 static TupleTableSlot *
2274 EvalPlanQualNext(EState *estate)
2276 evalPlanQual *epq = estate->es_evalPlanQual;
2277 MemoryContext oldcontext;
2278 TupleTableSlot *slot;
2280 Assert(epq->rti != 0);
2283 oldcontext = MemoryContextSwitchTo(epq->estate->es_query_cxt);
2284 slot = ExecProcNode(epq->planstate);
2285 MemoryContextSwitchTo(oldcontext);
2288 * No more tuples for this PQ. Continue previous one.
2290 if (TupIsNull(slot))
2292 evalPlanQual *oldepq;
2294 /* stop execution */
2295 EvalPlanQualStop(epq);
2296 /* pop old PQ from the stack */
2300 /* this is the first (oldest) PQ - mark as free */
2302 estate->es_useEvalPlan = false;
2303 /* and continue Query execution */
2306 Assert(oldepq->rti != 0);
2307 /* push current PQ to freePQ stack */
2310 estate->es_evalPlanQual = epq;
2318 EndEvalPlanQual(EState *estate)
2320 evalPlanQual *epq = estate->es_evalPlanQual;
2322 if (epq->rti == 0) /* plans already shutdowned */
2324 Assert(epq->next == NULL);
2330 evalPlanQual *oldepq;
2332 /* stop execution */
2333 EvalPlanQualStop(epq);
2334 /* pop old PQ from the stack */
2338 /* this is the first (oldest) PQ - mark as free */
2340 estate->es_useEvalPlan = false;
2343 Assert(oldepq->rti != 0);
2344 /* push current PQ to freePQ stack */
2347 estate->es_evalPlanQual = epq;
2352 * Start execution of one level of PlanQual.
2354 * This is a cut-down version of ExecutorStart(): we copy some state from
2355 * the top-level estate rather than initializing it fresh.
2358 EvalPlanQualStart(evalPlanQual *epq, EState *estate, evalPlanQual *priorepq)
2362 MemoryContext oldcontext;
2365 rtsize = list_length(estate->es_range_table);
2367 epq->estate = epqstate = CreateExecutorState();
2369 oldcontext = MemoryContextSwitchTo(epqstate->es_query_cxt);
2372 * The epqstates share the top query's copy of unchanging state such as
2373 * the snapshot, rangetable, result-rel info, and external Param info.
2374 * They need their own copies of local state, including a tuple table,
2375 * es_param_exec_vals, etc.
2377 epqstate->es_direction = ForwardScanDirection;
2378 epqstate->es_snapshot = estate->es_snapshot;
2379 epqstate->es_crosscheck_snapshot = estate->es_crosscheck_snapshot;
2380 epqstate->es_range_table = estate->es_range_table;
2381 epqstate->es_output_cid = estate->es_output_cid;
2382 epqstate->es_result_relations = estate->es_result_relations;
2383 epqstate->es_num_result_relations = estate->es_num_result_relations;
2384 epqstate->es_result_relation_info = estate->es_result_relation_info;
2385 epqstate->es_junkFilter = estate->es_junkFilter;
2386 /* es_trig_target_relations must NOT be copied */
2387 epqstate->es_into_relation_descriptor = estate->es_into_relation_descriptor;
2388 epqstate->es_into_relation_use_wal = estate->es_into_relation_use_wal;
2389 epqstate->es_param_list_info = estate->es_param_list_info;
2390 if (estate->es_plannedstmt->nParamExec > 0)
2391 epqstate->es_param_exec_vals = (ParamExecData *)
2392 palloc0(estate->es_plannedstmt->nParamExec * sizeof(ParamExecData));
2393 epqstate->es_rowMarks = estate->es_rowMarks;
2394 epqstate->es_instrument = estate->es_instrument;
2395 epqstate->es_select_into = estate->es_select_into;
2396 epqstate->es_into_oids = estate->es_into_oids;
2397 epqstate->es_plannedstmt = estate->es_plannedstmt;
2400 * Each epqstate must have its own es_evTupleNull state, but all the stack
2401 * entries share es_evTuple state. This allows sub-rechecks to inherit
2402 * the value being examined by an outer recheck.
2404 epqstate->es_evTupleNull = (bool *) palloc0(rtsize * sizeof(bool));
2405 if (priorepq == NULL)
2406 /* first PQ stack entry */
2407 epqstate->es_evTuple = (HeapTuple *)
2408 palloc0(rtsize * sizeof(HeapTuple));
2410 /* later stack entries share the same storage */
2411 epqstate->es_evTuple = priorepq->estate->es_evTuple;
2414 * Create sub-tuple-table; we needn't redo the CountSlots work though.
2416 epqstate->es_tupleTable =
2417 ExecCreateTupleTable(estate->es_tupleTable->size);
2420 * Initialize private state information for each SubPlan. We must do this
2421 * before running ExecInitNode on the main query tree, since
2422 * ExecInitSubPlan expects to be able to find these entries.
2424 Assert(epqstate->es_subplanstates == NIL);
2425 foreach(l, estate->es_plannedstmt->subplans)
2427 Plan *subplan = (Plan *) lfirst(l);
2428 PlanState *subplanstate;
2430 subplanstate = ExecInitNode(subplan, epqstate, 0);
2432 epqstate->es_subplanstates = lappend(epqstate->es_subplanstates,
2437 * Initialize the private state information for all the nodes in the query
2438 * tree. This opens files, allocates storage and leaves us ready to start
2439 * processing tuples.
2441 epq->planstate = ExecInitNode(estate->es_plannedstmt->planTree, epqstate, 0);
2443 MemoryContextSwitchTo(oldcontext);
2447 * End execution of one level of PlanQual.
2449 * This is a cut-down version of ExecutorEnd(); basically we want to do most
2450 * of the normal cleanup, but *not* close result relations (which we are
2451 * just sharing from the outer query). We do, however, have to close any
2452 * trigger target relations that got opened, since those are not shared.
2455 EvalPlanQualStop(evalPlanQual *epq)
2457 EState *epqstate = epq->estate;
2458 MemoryContext oldcontext;
2461 oldcontext = MemoryContextSwitchTo(epqstate->es_query_cxt);
2463 ExecEndNode(epq->planstate);
2465 foreach(l, epqstate->es_subplanstates)
2467 PlanState *subplanstate = (PlanState *) lfirst(l);
2469 ExecEndNode(subplanstate);
2472 ExecDropTupleTable(epqstate->es_tupleTable, true);
2473 epqstate->es_tupleTable = NULL;
2475 if (epqstate->es_evTuple[epq->rti - 1] != NULL)
2477 heap_freetuple(epqstate->es_evTuple[epq->rti - 1]);
2478 epqstate->es_evTuple[epq->rti - 1] = NULL;
2481 foreach(l, epqstate->es_trig_target_relations)
2483 ResultRelInfo *resultRelInfo = (ResultRelInfo *) lfirst(l);
2485 /* Close indices and then the relation itself */
2486 ExecCloseIndices(resultRelInfo);
2487 heap_close(resultRelInfo->ri_RelationDesc, NoLock);
2490 MemoryContextSwitchTo(oldcontext);
2492 FreeExecutorState(epqstate);
2495 epq->planstate = NULL;
2499 * ExecGetActivePlanTree --- get the active PlanState tree from a QueryDesc
2501 * Ordinarily this is just the one mentioned in the QueryDesc, but if we
2502 * are looking at a row returned by the EvalPlanQual machinery, we need
2503 * to look at the subsidiary state instead.
2506 ExecGetActivePlanTree(QueryDesc *queryDesc)
2508 EState *estate = queryDesc->estate;
2510 if (estate && estate->es_useEvalPlan && estate->es_evalPlanQual != NULL)
2511 return estate->es_evalPlanQual->planstate;
2513 return queryDesc->planstate;
2518 * Support for SELECT INTO (a/k/a CREATE TABLE AS)
2520 * We implement SELECT INTO by diverting SELECT's normal output with
2521 * a specialized DestReceiver type.
2523 * TODO: remove some of the INTO-specific cruft from EState, and keep
2524 * it in the DestReceiver instead.
2529 DestReceiver pub; /* publicly-known function pointers */
2530 EState *estate; /* EState we are working with */
2534 * OpenIntoRel --- actually create the SELECT INTO target relation
2536 * This also replaces QueryDesc->dest with the special DestReceiver for
2537 * SELECT INTO. We assume that the correct result tuple type has already
2538 * been placed in queryDesc->tupDesc.
2541 OpenIntoRel(QueryDesc *queryDesc)
2543 IntoClause *into = queryDesc->plannedstmt->intoClause;
2544 EState *estate = queryDesc->estate;
2545 Relation intoRelationDesc;
2550 AclResult aclresult;
2553 DR_intorel *myState;
2558 * Check consistency of arguments
2560 if (into->onCommit != ONCOMMIT_NOOP && !into->rel->istemp)
2562 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
2563 errmsg("ON COMMIT can only be used on temporary tables")));
2566 * Find namespace to create in, check its permissions
2568 intoName = into->rel->relname;
2569 namespaceId = RangeVarGetCreationNamespace(into->rel);
2571 aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(),
2573 if (aclresult != ACLCHECK_OK)
2574 aclcheck_error(aclresult, ACL_KIND_NAMESPACE,
2575 get_namespace_name(namespaceId));
2578 * Select tablespace to use. If not specified, use default tablespace
2579 * (which may in turn default to database's default).
2581 if (into->tableSpaceName)
2583 tablespaceId = get_tablespace_oid(into->tableSpaceName);
2584 if (!OidIsValid(tablespaceId))
2586 (errcode(ERRCODE_UNDEFINED_OBJECT),
2587 errmsg("tablespace \"%s\" does not exist",
2588 into->tableSpaceName)));
2592 tablespaceId = GetDefaultTablespace(into->rel->istemp);
2593 /* note InvalidOid is OK in this case */
2596 /* Check permissions except when using the database's default space */
2597 if (OidIsValid(tablespaceId))
2599 AclResult aclresult;
2601 aclresult = pg_tablespace_aclcheck(tablespaceId, GetUserId(),
2604 if (aclresult != ACLCHECK_OK)
2605 aclcheck_error(aclresult, ACL_KIND_TABLESPACE,
2606 get_tablespace_name(tablespaceId));
2609 /* Parse and validate any reloptions */
2610 reloptions = transformRelOptions((Datum) 0,
2614 (void) heap_reloptions(RELKIND_RELATION, reloptions, true);
2616 /* have to copy the actual tupdesc to get rid of any constraints */
2617 tupdesc = CreateTupleDescCopy(queryDesc->tupDesc);
2619 /* Now we can actually create the new relation */
2620 intoRelationId = heap_create_with_catalog(intoName,
2632 allowSystemTableMods);
2634 FreeTupleDesc(tupdesc);
2637 * Advance command counter so that the newly-created relation's catalog
2638 * tuples will be visible to heap_open.
2640 CommandCounterIncrement();
2643 * If necessary, create a TOAST table for the INTO relation. Note that
2644 * AlterTableCreateToastTable ends with CommandCounterIncrement(), so that
2645 * the TOAST table will be visible for insertion.
2647 AlterTableCreateToastTable(intoRelationId);
2650 * And open the constructed table for writing.
2652 intoRelationDesc = heap_open(intoRelationId, AccessExclusiveLock);
2654 /* use_wal off requires rd_targblock be initially invalid */
2655 Assert(intoRelationDesc->rd_targblock == InvalidBlockNumber);
2658 * We can skip WAL-logging the insertions, unless PITR is in use.
2660 estate->es_into_relation_use_wal = XLogArchivingActive();
2661 estate->es_into_relation_descriptor = intoRelationDesc;
2664 * Now replace the query's DestReceiver with one for SELECT INTO
2666 queryDesc->dest = CreateDestReceiver(DestIntoRel, NULL);
2667 myState = (DR_intorel *) queryDesc->dest;
2668 Assert(myState->pub.mydest == DestIntoRel);
2669 myState->estate = estate;
2673 * CloseIntoRel --- clean up SELECT INTO at ExecutorEnd time
2676 CloseIntoRel(QueryDesc *queryDesc)
2678 EState *estate = queryDesc->estate;
2680 /* OpenIntoRel might never have gotten called */
2681 if (estate->es_into_relation_descriptor)
2683 /* If we skipped using WAL, must heap_sync before commit */
2684 if (!estate->es_into_relation_use_wal)
2685 heap_sync(estate->es_into_relation_descriptor);
2687 /* close rel, but keep lock until commit */
2688 heap_close(estate->es_into_relation_descriptor, NoLock);
2690 estate->es_into_relation_descriptor = NULL;
2695 * CreateIntoRelDestReceiver -- create a suitable DestReceiver object
2697 * Since CreateDestReceiver doesn't accept the parameters we'd need,
2698 * we just leave the private fields empty here. OpenIntoRel will
2702 CreateIntoRelDestReceiver(void)
2704 DR_intorel *self = (DR_intorel *) palloc(sizeof(DR_intorel));
2706 self->pub.receiveSlot = intorel_receive;
2707 self->pub.rStartup = intorel_startup;
2708 self->pub.rShutdown = intorel_shutdown;
2709 self->pub.rDestroy = intorel_destroy;
2710 self->pub.mydest = DestIntoRel;
2712 self->estate = NULL;
2714 return (DestReceiver *) self;
2718 * intorel_startup --- executor startup
2721 intorel_startup(DestReceiver *self, int operation, TupleDesc typeinfo)
2727 * intorel_receive --- receive one tuple
2730 intorel_receive(TupleTableSlot *slot, DestReceiver *self)
2732 DR_intorel *myState = (DR_intorel *) self;
2733 EState *estate = myState->estate;
2736 tuple = ExecCopySlotTuple(slot);
2738 heap_insert(estate->es_into_relation_descriptor,
2740 estate->es_output_cid,
2741 estate->es_into_relation_use_wal,
2742 false); /* never any point in using FSM */
2744 /* We know this is a newly created relation, so there are no indexes */
2746 heap_freetuple(tuple);
2752 * intorel_shutdown --- executor end
2755 intorel_shutdown(DestReceiver *self)
2761 * intorel_destroy --- release DestReceiver object
2764 intorel_destroy(DestReceiver *self)