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11 * The old ExecutorMain() has been replaced by ExecutorStart(),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) 1996-2008, PostgreSQL Global Development Group
25 * Portions Copyright (c) 1994, Regents of the University of California
29 * $PostgreSQL: pgsql/src/backend/executor/execMain.c,v 1.305 2008/03/28 00:21:55 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"
55 #include "utils/tqual.h"
58 typedef struct evalPlanQual
63 struct evalPlanQual *next; /* stack of active PlanQual plans */
64 struct evalPlanQual *free; /* list of free PlanQual plans */
67 /* decls for local routines only used within this module */
68 static void InitPlan(QueryDesc *queryDesc, int eflags);
69 static void ExecEndPlan(PlanState *planstate, EState *estate);
70 static TupleTableSlot *ExecutePlan(EState *estate, PlanState *planstate,
73 ScanDirection direction,
75 static void ExecSelect(TupleTableSlot *slot,
76 DestReceiver *dest, EState *estate);
77 static void ExecInsert(TupleTableSlot *slot, ItemPointer tupleid,
78 TupleTableSlot *planSlot,
79 DestReceiver *dest, EState *estate);
80 static void ExecDelete(ItemPointer tupleid,
81 TupleTableSlot *planSlot,
82 DestReceiver *dest, EState *estate);
83 static void ExecUpdate(TupleTableSlot *slot, ItemPointer tupleid,
84 TupleTableSlot *planSlot,
85 DestReceiver *dest, EState *estate);
86 static void ExecProcessReturning(ProjectionInfo *projectReturning,
87 TupleTableSlot *tupleSlot,
88 TupleTableSlot *planSlot,
90 static TupleTableSlot *EvalPlanQualNext(EState *estate);
91 static void EndEvalPlanQual(EState *estate);
92 static void ExecCheckRTPerms(List *rangeTable);
93 static void ExecCheckRTEPerms(RangeTblEntry *rte);
94 static void ExecCheckXactReadOnly(PlannedStmt *plannedstmt);
95 static void EvalPlanQualStart(evalPlanQual *epq, EState *estate,
96 evalPlanQual *priorepq);
97 static void EvalPlanQualStop(evalPlanQual *epq);
98 static void OpenIntoRel(QueryDesc *queryDesc);
99 static void CloseIntoRel(QueryDesc *queryDesc);
100 static void intorel_startup(DestReceiver *self, int operation, TupleDesc typeinfo);
101 static void intorel_receive(TupleTableSlot *slot, DestReceiver *self);
102 static void intorel_shutdown(DestReceiver *self);
103 static void intorel_destroy(DestReceiver *self);
105 /* end of local decls */
108 /* ----------------------------------------------------------------
111 * This routine must be called at the beginning of any execution of any
114 * Takes a QueryDesc previously created by CreateQueryDesc (it's not real
115 * clear why we bother to separate the two functions, but...). The tupDesc
116 * field of the QueryDesc is filled in to describe the tuples that will be
117 * returned, and the internal fields (estate and planstate) are set up.
119 * eflags contains flag bits as described in executor.h.
121 * NB: the CurrentMemoryContext when this is called will become the parent
122 * of the per-query context used for this Executor invocation.
123 * ----------------------------------------------------------------
126 ExecutorStart(QueryDesc *queryDesc, int eflags)
129 MemoryContext oldcontext;
131 /* sanity checks: queryDesc must not be started already */
132 Assert(queryDesc != NULL);
133 Assert(queryDesc->estate == NULL);
136 * If the transaction is read-only, we need to check if any writes are
137 * planned to non-temporary tables. EXPLAIN is considered read-only.
139 if (XactReadOnly && !(eflags & EXEC_FLAG_EXPLAIN_ONLY))
140 ExecCheckXactReadOnly(queryDesc->plannedstmt);
143 * Build EState, switch into per-query memory context for startup.
145 estate = CreateExecutorState();
146 queryDesc->estate = estate;
148 oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
151 * Fill in parameters, if any, from queryDesc
153 estate->es_param_list_info = queryDesc->params;
155 if (queryDesc->plannedstmt->nParamExec > 0)
156 estate->es_param_exec_vals = (ParamExecData *)
157 palloc0(queryDesc->plannedstmt->nParamExec * sizeof(ParamExecData));
160 * If non-read-only query, set the command ID to mark output tuples with
162 switch (queryDesc->operation)
165 /* SELECT INTO and SELECT FOR UPDATE/SHARE need to mark tuples */
166 if (queryDesc->plannedstmt->intoClause != NULL ||
167 queryDesc->plannedstmt->rowMarks != NIL)
168 estate->es_output_cid = GetCurrentCommandId(true);
174 estate->es_output_cid = GetCurrentCommandId(true);
178 elog(ERROR, "unrecognized operation code: %d",
179 (int) queryDesc->operation);
184 * Copy other important information into the EState
186 estate->es_snapshot = queryDesc->snapshot;
187 estate->es_crosscheck_snapshot = queryDesc->crosscheck_snapshot;
188 estate->es_instrument = queryDesc->doInstrument;
191 * Initialize the plan state tree
193 InitPlan(queryDesc, eflags);
195 MemoryContextSwitchTo(oldcontext);
198 /* ----------------------------------------------------------------
201 * This is the main routine of the executor module. It accepts
202 * the query descriptor from the traffic cop and executes the
205 * ExecutorStart must have been called already.
207 * If direction is NoMovementScanDirection then nothing is done
208 * except to start up/shut down the destination. Otherwise,
209 * we retrieve up to 'count' tuples in the specified direction.
211 * Note: count = 0 is interpreted as no portal limit, i.e., run to
214 * ----------------------------------------------------------------
217 ExecutorRun(QueryDesc *queryDesc,
218 ScanDirection direction, long count)
224 TupleTableSlot *result;
225 MemoryContext oldcontext;
228 Assert(queryDesc != NULL);
230 estate = queryDesc->estate;
232 Assert(estate != NULL);
235 * Switch into per-query memory context
237 oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
240 * extract information from the query descriptor and the query feature.
242 operation = queryDesc->operation;
243 dest = queryDesc->dest;
246 * startup tuple receiver, if we will be emitting tuples
248 estate->es_processed = 0;
249 estate->es_lastoid = InvalidOid;
251 sendTuples = (operation == CMD_SELECT ||
252 queryDesc->plannedstmt->returningLists);
255 (*dest->rStartup) (dest, operation, queryDesc->tupDesc);
260 if (ScanDirectionIsNoMovement(direction))
263 result = ExecutePlan(estate,
264 queryDesc->planstate,
271 * shutdown tuple receiver, if we started it
274 (*dest->rShutdown) (dest);
276 MemoryContextSwitchTo(oldcontext);
281 /* ----------------------------------------------------------------
284 * This routine must be called at the end of execution of any
286 * ----------------------------------------------------------------
289 ExecutorEnd(QueryDesc *queryDesc)
292 MemoryContext oldcontext;
295 Assert(queryDesc != NULL);
297 estate = queryDesc->estate;
299 Assert(estate != NULL);
302 * Switch into per-query memory context to run ExecEndPlan
304 oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
306 ExecEndPlan(queryDesc->planstate, estate);
309 * Close the SELECT INTO relation if any
311 if (estate->es_select_into)
312 CloseIntoRel(queryDesc);
315 * Must switch out of context before destroying it
317 MemoryContextSwitchTo(oldcontext);
320 * Release EState and per-query memory context. This should release
321 * everything the executor has allocated.
323 FreeExecutorState(estate);
325 /* Reset queryDesc fields that no longer point to anything */
326 queryDesc->tupDesc = NULL;
327 queryDesc->estate = NULL;
328 queryDesc->planstate = NULL;
331 /* ----------------------------------------------------------------
334 * This routine may be called on an open queryDesc to rewind it
336 * ----------------------------------------------------------------
339 ExecutorRewind(QueryDesc *queryDesc)
342 MemoryContext oldcontext;
345 Assert(queryDesc != NULL);
347 estate = queryDesc->estate;
349 Assert(estate != NULL);
351 /* It's probably not sensible to rescan updating queries */
352 Assert(queryDesc->operation == CMD_SELECT);
355 * Switch into per-query memory context
357 oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
362 ExecReScan(queryDesc->planstate, NULL);
364 MemoryContextSwitchTo(oldcontext);
370 * Check access permissions for all relations listed in a range table.
373 ExecCheckRTPerms(List *rangeTable)
377 foreach(l, rangeTable)
379 ExecCheckRTEPerms((RangeTblEntry *) lfirst(l));
385 * Check access permissions for a single RTE.
388 ExecCheckRTEPerms(RangeTblEntry *rte)
390 AclMode requiredPerms;
395 * Only plain-relation RTEs need to be checked here. Function RTEs are
396 * checked by init_fcache when the function is prepared for execution.
397 * Join, subquery, and special RTEs need no checks.
399 if (rte->rtekind != RTE_RELATION)
403 * No work if requiredPerms is empty.
405 requiredPerms = rte->requiredPerms;
406 if (requiredPerms == 0)
412 * userid to check as: current user unless we have a setuid indication.
414 * Note: GetUserId() is presently fast enough that there's no harm in
415 * calling it separately for each RTE. If that stops being true, we could
416 * call it once in ExecCheckRTPerms and pass the userid down from there.
417 * But for now, no need for the extra clutter.
419 userid = rte->checkAsUser ? rte->checkAsUser : GetUserId();
422 * We must have *all* the requiredPerms bits, so use aclmask not aclcheck.
424 if (pg_class_aclmask(relOid, userid, requiredPerms, ACLMASK_ALL)
426 aclcheck_error(ACLCHECK_NO_PRIV, ACL_KIND_CLASS,
427 get_rel_name(relOid));
431 * Check that the query does not imply any writes to non-temp tables.
434 ExecCheckXactReadOnly(PlannedStmt *plannedstmt)
439 * CREATE TABLE AS or SELECT INTO?
441 * XXX should we allow this if the destination is temp?
443 if (plannedstmt->intoClause != NULL)
446 /* Fail if write permissions are requested on any non-temp table */
447 foreach(l, plannedstmt->rtable)
449 RangeTblEntry *rte = (RangeTblEntry *) lfirst(l);
451 if (rte->rtekind != RTE_RELATION)
454 if ((rte->requiredPerms & (~ACL_SELECT)) == 0)
457 if (isTempNamespace(get_rel_namespace(rte->relid)))
467 (errcode(ERRCODE_READ_ONLY_SQL_TRANSACTION),
468 errmsg("transaction is read-only")));
472 /* ----------------------------------------------------------------
475 * Initializes the query plan: open files, allocate storage
476 * and start up the rule manager
477 * ----------------------------------------------------------------
480 InitPlan(QueryDesc *queryDesc, int eflags)
482 CmdType operation = queryDesc->operation;
483 PlannedStmt *plannedstmt = queryDesc->plannedstmt;
484 Plan *plan = plannedstmt->planTree;
485 List *rangeTable = plannedstmt->rtable;
486 EState *estate = queryDesc->estate;
487 PlanState *planstate;
493 * Do permissions checks
495 ExecCheckRTPerms(rangeTable);
498 * initialize the node's execution state
500 estate->es_range_table = rangeTable;
503 * initialize result relation stuff
505 if (plannedstmt->resultRelations)
507 List *resultRelations = plannedstmt->resultRelations;
508 int numResultRelations = list_length(resultRelations);
509 ResultRelInfo *resultRelInfos;
510 ResultRelInfo *resultRelInfo;
512 resultRelInfos = (ResultRelInfo *)
513 palloc(numResultRelations * sizeof(ResultRelInfo));
514 resultRelInfo = resultRelInfos;
515 foreach(l, resultRelations)
517 Index resultRelationIndex = lfirst_int(l);
518 Oid resultRelationOid;
519 Relation resultRelation;
521 resultRelationOid = getrelid(resultRelationIndex, rangeTable);
522 resultRelation = heap_open(resultRelationOid, RowExclusiveLock);
523 InitResultRelInfo(resultRelInfo,
527 estate->es_instrument);
530 estate->es_result_relations = resultRelInfos;
531 estate->es_num_result_relations = numResultRelations;
532 /* Initialize to first or only result rel */
533 estate->es_result_relation_info = resultRelInfos;
538 * if no result relation, then set state appropriately
540 estate->es_result_relations = NULL;
541 estate->es_num_result_relations = 0;
542 estate->es_result_relation_info = NULL;
546 * Detect whether we're doing SELECT INTO. If so, set the es_into_oids
547 * flag appropriately so that the plan tree will be initialized with the
548 * correct tuple descriptors. (Other SELECT INTO stuff comes later.)
550 estate->es_select_into = false;
551 if (operation == CMD_SELECT && plannedstmt->intoClause != NULL)
553 estate->es_select_into = true;
554 estate->es_into_oids = interpretOidsOption(plannedstmt->intoClause->options);
558 * Have to lock relations selected FOR UPDATE/FOR SHARE before we
559 * initialize the plan tree, else we'd be doing a lock upgrade. While we
560 * are at it, build the ExecRowMark list.
562 estate->es_rowMarks = NIL;
563 foreach(l, plannedstmt->rowMarks)
565 RowMarkClause *rc = (RowMarkClause *) lfirst(l);
566 Oid relid = getrelid(rc->rti, rangeTable);
570 relation = heap_open(relid, RowShareLock);
571 erm = (ExecRowMark *) palloc(sizeof(ExecRowMark));
572 erm->relation = relation;
574 erm->forUpdate = rc->forUpdate;
575 erm->noWait = rc->noWait;
576 /* We'll set up ctidAttno below */
577 erm->ctidAttNo = InvalidAttrNumber;
578 estate->es_rowMarks = lappend(estate->es_rowMarks, erm);
582 * Initialize the executor "tuple" table. We need slots for all the plan
583 * nodes, plus possibly output slots for the junkfilter(s). At this point
584 * we aren't sure if we need junkfilters, so just add slots for them
585 * unconditionally. Also, if it's not a SELECT, set up a slot for use for
586 * trigger output tuples. Also, one for RETURNING-list evaluation.
591 /* Slots for the main plan tree */
592 nSlots = ExecCountSlotsNode(plan);
593 /* Add slots for subplans and initplans */
594 foreach(l, plannedstmt->subplans)
596 Plan *subplan = (Plan *) lfirst(l);
598 nSlots += ExecCountSlotsNode(subplan);
600 /* Add slots for junkfilter(s) */
601 if (plannedstmt->resultRelations != NIL)
602 nSlots += list_length(plannedstmt->resultRelations);
605 if (operation != CMD_SELECT)
606 nSlots++; /* for es_trig_tuple_slot */
607 if (plannedstmt->returningLists)
608 nSlots++; /* for RETURNING projection */
610 estate->es_tupleTable = ExecCreateTupleTable(nSlots);
612 if (operation != CMD_SELECT)
613 estate->es_trig_tuple_slot =
614 ExecAllocTableSlot(estate->es_tupleTable);
617 /* mark EvalPlanQual not active */
618 estate->es_plannedstmt = plannedstmt;
619 estate->es_evalPlanQual = NULL;
620 estate->es_evTupleNull = NULL;
621 estate->es_evTuple = NULL;
622 estate->es_useEvalPlan = false;
625 * Initialize private state information for each SubPlan. We must do this
626 * before running ExecInitNode on the main query tree, since
627 * ExecInitSubPlan expects to be able to find these entries.
629 Assert(estate->es_subplanstates == NIL);
630 i = 1; /* subplan indices count from 1 */
631 foreach(l, plannedstmt->subplans)
633 Plan *subplan = (Plan *) lfirst(l);
634 PlanState *subplanstate;
638 * A subplan will never need to do BACKWARD scan nor MARK/RESTORE. If
639 * it is a parameterless subplan (not initplan), we suggest that it be
640 * prepared to handle REWIND efficiently; otherwise there is no need.
642 sp_eflags = eflags & EXEC_FLAG_EXPLAIN_ONLY;
643 if (bms_is_member(i, plannedstmt->rewindPlanIDs))
644 sp_eflags |= EXEC_FLAG_REWIND;
646 subplanstate = ExecInitNode(subplan, estate, sp_eflags);
648 estate->es_subplanstates = lappend(estate->es_subplanstates,
655 * Initialize the private state information for all the nodes in the query
656 * tree. This opens files, allocates storage and leaves us ready to start
659 planstate = ExecInitNode(plan, estate, eflags);
662 * Get the tuple descriptor describing the type of tuples to return. (this
663 * is especially important if we are creating a relation with "SELECT
666 tupType = ExecGetResultType(planstate);
669 * Initialize the junk filter if needed. SELECT and INSERT queries need a
670 * filter if there are any junk attrs in the tlist. INSERT and SELECT
671 * INTO also need a filter if the plan may return raw disk tuples (else
672 * heap_insert will be scribbling on the source relation!). UPDATE and
673 * DELETE always need a filter, since there's always a junk 'ctid'
674 * attribute present --- no need to look first.
677 bool junk_filter_needed = false;
684 foreach(tlist, plan->targetlist)
686 TargetEntry *tle = (TargetEntry *) lfirst(tlist);
690 junk_filter_needed = true;
694 if (!junk_filter_needed &&
695 (operation == CMD_INSERT || estate->es_select_into) &&
696 ExecMayReturnRawTuples(planstate))
697 junk_filter_needed = true;
701 junk_filter_needed = true;
707 if (junk_filter_needed)
710 * If there are multiple result relations, each one needs its own
711 * junk filter. Note this is only possible for UPDATE/DELETE, so
712 * we can't be fooled by some needing a filter and some not.
714 if (list_length(plannedstmt->resultRelations) > 1)
716 PlanState **appendplans;
718 ResultRelInfo *resultRelInfo;
720 /* Top plan had better be an Append here. */
721 Assert(IsA(plan, Append));
722 Assert(((Append *) plan)->isTarget);
723 Assert(IsA(planstate, AppendState));
724 appendplans = ((AppendState *) planstate)->appendplans;
725 as_nplans = ((AppendState *) planstate)->as_nplans;
726 Assert(as_nplans == estate->es_num_result_relations);
727 resultRelInfo = estate->es_result_relations;
728 for (i = 0; i < as_nplans; i++)
730 PlanState *subplan = appendplans[i];
733 j = ExecInitJunkFilter(subplan->plan->targetlist,
734 resultRelInfo->ri_RelationDesc->rd_att->tdhasoid,
735 ExecAllocTableSlot(estate->es_tupleTable));
738 * Since it must be UPDATE/DELETE, there had better be a
739 * "ctid" junk attribute in the tlist ... but ctid could
740 * be at a different resno for each result relation. We
741 * look up the ctid resnos now and save them in the
744 j->jf_junkAttNo = ExecFindJunkAttribute(j, "ctid");
745 if (!AttributeNumberIsValid(j->jf_junkAttNo))
746 elog(ERROR, "could not find junk ctid column");
747 resultRelInfo->ri_junkFilter = j;
752 * Set active junkfilter too; at this point ExecInitAppend has
753 * already selected an active result relation...
755 estate->es_junkFilter =
756 estate->es_result_relation_info->ri_junkFilter;
760 /* Normal case with just one JunkFilter */
763 j = ExecInitJunkFilter(planstate->plan->targetlist,
765 ExecAllocTableSlot(estate->es_tupleTable));
766 estate->es_junkFilter = j;
767 if (estate->es_result_relation_info)
768 estate->es_result_relation_info->ri_junkFilter = j;
770 if (operation == CMD_SELECT)
772 /* For SELECT, want to return the cleaned tuple type */
773 tupType = j->jf_cleanTupType;
774 /* For SELECT FOR UPDATE/SHARE, find the ctid attrs now */
775 foreach(l, estate->es_rowMarks)
777 ExecRowMark *erm = (ExecRowMark *) lfirst(l);
780 snprintf(resname, sizeof(resname), "ctid%u", erm->rti);
781 erm->ctidAttNo = ExecFindJunkAttribute(j, resname);
782 if (!AttributeNumberIsValid(erm->ctidAttNo))
783 elog(ERROR, "could not find junk \"%s\" column",
787 else if (operation == CMD_UPDATE || operation == CMD_DELETE)
789 /* For UPDATE/DELETE, find the ctid junk attr now */
790 j->jf_junkAttNo = ExecFindJunkAttribute(j, "ctid");
791 if (!AttributeNumberIsValid(j->jf_junkAttNo))
792 elog(ERROR, "could not find junk ctid column");
797 estate->es_junkFilter = NULL;
801 * Initialize RETURNING projections if needed.
803 if (plannedstmt->returningLists)
805 TupleTableSlot *slot;
806 ExprContext *econtext;
807 ResultRelInfo *resultRelInfo;
810 * We set QueryDesc.tupDesc to be the RETURNING rowtype in this case.
811 * We assume all the sublists will generate the same output tupdesc.
813 tupType = ExecTypeFromTL((List *) linitial(plannedstmt->returningLists),
816 /* Set up a slot for the output of the RETURNING projection(s) */
817 slot = ExecAllocTableSlot(estate->es_tupleTable);
818 ExecSetSlotDescriptor(slot, tupType);
819 /* Need an econtext too */
820 econtext = CreateExprContext(estate);
823 * Build a projection for each result rel. Note that any SubPlans in
824 * the RETURNING lists get attached to the topmost plan node.
826 Assert(list_length(plannedstmt->returningLists) == estate->es_num_result_relations);
827 resultRelInfo = estate->es_result_relations;
828 foreach(l, plannedstmt->returningLists)
830 List *rlist = (List *) lfirst(l);
833 rliststate = (List *) ExecInitExpr((Expr *) rlist, planstate);
834 resultRelInfo->ri_projectReturning =
835 ExecBuildProjectionInfo(rliststate, econtext, slot,
836 resultRelInfo->ri_RelationDesc->rd_att);
841 queryDesc->tupDesc = tupType;
842 queryDesc->planstate = planstate;
845 * If doing SELECT INTO, initialize the "into" relation. We must wait
846 * till now so we have the "clean" result tuple type to create the new
849 * If EXPLAIN, skip creating the "into" relation.
851 if (estate->es_select_into && !(eflags & EXEC_FLAG_EXPLAIN_ONLY))
852 OpenIntoRel(queryDesc);
856 * Initialize ResultRelInfo data for one result relation
859 InitResultRelInfo(ResultRelInfo *resultRelInfo,
860 Relation resultRelationDesc,
861 Index resultRelationIndex,
866 * Check valid relkind ... parser and/or planner should have noticed this
867 * already, but let's make sure.
869 switch (resultRelationDesc->rd_rel->relkind)
871 case RELKIND_RELATION:
874 case RELKIND_SEQUENCE:
876 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
877 errmsg("cannot change sequence \"%s\"",
878 RelationGetRelationName(resultRelationDesc))));
880 case RELKIND_TOASTVALUE:
882 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
883 errmsg("cannot change TOAST relation \"%s\"",
884 RelationGetRelationName(resultRelationDesc))));
888 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
889 errmsg("cannot change view \"%s\"",
890 RelationGetRelationName(resultRelationDesc))));
894 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
895 errmsg("cannot change relation \"%s\"",
896 RelationGetRelationName(resultRelationDesc))));
900 /* OK, fill in the node */
901 MemSet(resultRelInfo, 0, sizeof(ResultRelInfo));
902 resultRelInfo->type = T_ResultRelInfo;
903 resultRelInfo->ri_RangeTableIndex = resultRelationIndex;
904 resultRelInfo->ri_RelationDesc = resultRelationDesc;
905 resultRelInfo->ri_NumIndices = 0;
906 resultRelInfo->ri_IndexRelationDescs = NULL;
907 resultRelInfo->ri_IndexRelationInfo = NULL;
908 /* make a copy so as not to depend on relcache info not changing... */
909 resultRelInfo->ri_TrigDesc = CopyTriggerDesc(resultRelationDesc->trigdesc);
910 if (resultRelInfo->ri_TrigDesc)
912 int n = resultRelInfo->ri_TrigDesc->numtriggers;
914 resultRelInfo->ri_TrigFunctions = (FmgrInfo *)
915 palloc0(n * sizeof(FmgrInfo));
917 resultRelInfo->ri_TrigInstrument = InstrAlloc(n);
919 resultRelInfo->ri_TrigInstrument = NULL;
923 resultRelInfo->ri_TrigFunctions = NULL;
924 resultRelInfo->ri_TrigInstrument = NULL;
926 resultRelInfo->ri_ConstraintExprs = NULL;
927 resultRelInfo->ri_junkFilter = NULL;
928 resultRelInfo->ri_projectReturning = NULL;
931 * If there are indices on the result relation, open them and save
932 * descriptors in the result relation info, so that we can add new index
933 * entries for the tuples we add/update. We need not do this for a
934 * DELETE, however, since deletion doesn't affect indexes.
936 if (resultRelationDesc->rd_rel->relhasindex &&
937 operation != CMD_DELETE)
938 ExecOpenIndices(resultRelInfo);
942 * ExecGetTriggerResultRel
944 * Get a ResultRelInfo for a trigger target relation. Most of the time,
945 * triggers are fired on one of the result relations of the query, and so
946 * we can just return a member of the es_result_relations array. (Note: in
947 * self-join situations there might be multiple members with the same OID;
948 * if so it doesn't matter which one we pick.) However, it is sometimes
949 * necessary to fire triggers on other relations; this happens mainly when an
950 * RI update trigger queues additional triggers on other relations, which will
951 * be processed in the context of the outer query. For efficiency's sake,
952 * we want to have a ResultRelInfo for those triggers too; that can avoid
953 * repeated re-opening of the relation. (It also provides a way for EXPLAIN
954 * ANALYZE to report the runtimes of such triggers.) So we make additional
955 * ResultRelInfo's as needed, and save them in es_trig_target_relations.
958 ExecGetTriggerResultRel(EState *estate, Oid relid)
960 ResultRelInfo *rInfo;
964 MemoryContext oldcontext;
966 /* First, search through the query result relations */
967 rInfo = estate->es_result_relations;
968 nr = estate->es_num_result_relations;
971 if (RelationGetRelid(rInfo->ri_RelationDesc) == relid)
976 /* Nope, but maybe we already made an extra ResultRelInfo for it */
977 foreach(l, estate->es_trig_target_relations)
979 rInfo = (ResultRelInfo *) lfirst(l);
980 if (RelationGetRelid(rInfo->ri_RelationDesc) == relid)
983 /* Nope, so we need a new one */
986 * Open the target relation's relcache entry. We assume that an
987 * appropriate lock is still held by the backend from whenever the trigger
988 * event got queued, so we need take no new lock here.
990 rel = heap_open(relid, NoLock);
993 * Make the new entry in the right context. Currently, we don't need any
994 * index information in ResultRelInfos used only for triggers, so tell
995 * InitResultRelInfo it's a DELETE.
997 oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
998 rInfo = makeNode(ResultRelInfo);
999 InitResultRelInfo(rInfo,
1001 0, /* dummy rangetable index */
1003 estate->es_instrument);
1004 estate->es_trig_target_relations =
1005 lappend(estate->es_trig_target_relations, rInfo);
1006 MemoryContextSwitchTo(oldcontext);
1012 * ExecContextForcesOids
1014 * This is pretty grotty: when doing INSERT, UPDATE, or SELECT INTO,
1015 * we need to ensure that result tuples have space for an OID iff they are
1016 * going to be stored into a relation that has OIDs. In other contexts
1017 * we are free to choose whether to leave space for OIDs in result tuples
1018 * (we generally don't want to, but we do if a physical-tlist optimization
1019 * is possible). This routine checks the plan context and returns TRUE if the
1020 * choice is forced, FALSE if the choice is not forced. In the TRUE case,
1021 * *hasoids is set to the required value.
1023 * One reason this is ugly is that all plan nodes in the plan tree will emit
1024 * tuples with space for an OID, though we really only need the topmost node
1025 * to do so. However, node types like Sort don't project new tuples but just
1026 * return their inputs, and in those cases the requirement propagates down
1027 * to the input node. Eventually we might make this code smart enough to
1028 * recognize how far down the requirement really goes, but for now we just
1029 * make all plan nodes do the same thing if the top level forces the choice.
1031 * We assume that estate->es_result_relation_info is already set up to
1032 * describe the target relation. Note that in an UPDATE that spans an
1033 * inheritance tree, some of the target relations may have OIDs and some not.
1034 * We have to make the decisions on a per-relation basis as we initialize
1035 * each of the child plans of the topmost Append plan.
1037 * SELECT INTO is even uglier, because we don't have the INTO relation's
1038 * descriptor available when this code runs; we have to look aside at a
1039 * flag set by InitPlan().
1042 ExecContextForcesOids(PlanState *planstate, bool *hasoids)
1044 if (planstate->state->es_select_into)
1046 *hasoids = planstate->state->es_into_oids;
1051 ResultRelInfo *ri = planstate->state->es_result_relation_info;
1055 Relation rel = ri->ri_RelationDesc;
1059 *hasoids = rel->rd_rel->relhasoids;
1068 /* ----------------------------------------------------------------
1071 * Cleans up the query plan -- closes files and frees up storage
1073 * NOTE: we are no longer very worried about freeing storage per se
1074 * in this code; FreeExecutorState should be guaranteed to release all
1075 * memory that needs to be released. What we are worried about doing
1076 * is closing relations and dropping buffer pins. Thus, for example,
1077 * tuple tables must be cleared or dropped to ensure pins are released.
1078 * ----------------------------------------------------------------
1081 ExecEndPlan(PlanState *planstate, EState *estate)
1083 ResultRelInfo *resultRelInfo;
1088 * shut down any PlanQual processing we were doing
1090 if (estate->es_evalPlanQual != NULL)
1091 EndEvalPlanQual(estate);
1094 * shut down the node-type-specific query processing
1096 ExecEndNode(planstate);
1101 foreach(l, estate->es_subplanstates)
1103 PlanState *subplanstate = (PlanState *) lfirst(l);
1105 ExecEndNode(subplanstate);
1109 * destroy the executor "tuple" table.
1111 ExecDropTupleTable(estate->es_tupleTable, true);
1112 estate->es_tupleTable = NULL;
1115 * close the result relation(s) if any, but hold locks until xact commit.
1117 resultRelInfo = estate->es_result_relations;
1118 for (i = estate->es_num_result_relations; i > 0; i--)
1120 /* Close indices and then the relation itself */
1121 ExecCloseIndices(resultRelInfo);
1122 heap_close(resultRelInfo->ri_RelationDesc, NoLock);
1127 * likewise close any trigger target relations
1129 foreach(l, estate->es_trig_target_relations)
1131 resultRelInfo = (ResultRelInfo *) lfirst(l);
1132 /* Close indices and then the relation itself */
1133 ExecCloseIndices(resultRelInfo);
1134 heap_close(resultRelInfo->ri_RelationDesc, NoLock);
1138 * close any relations selected FOR UPDATE/FOR SHARE, again keeping locks
1140 foreach(l, estate->es_rowMarks)
1142 ExecRowMark *erm = lfirst(l);
1144 heap_close(erm->relation, NoLock);
1148 /* ----------------------------------------------------------------
1151 * processes the query plan to retrieve 'numberTuples' tuples in the
1152 * direction specified.
1154 * Retrieves all tuples if numberTuples is 0
1156 * result is either a slot containing the last tuple in the case
1157 * of a SELECT or NULL otherwise.
1159 * Note: the ctid attribute is a 'junk' attribute that is removed before the
1161 * ----------------------------------------------------------------
1163 static TupleTableSlot *
1164 ExecutePlan(EState *estate,
1165 PlanState *planstate,
1168 ScanDirection direction,
1171 JunkFilter *junkfilter;
1172 TupleTableSlot *planSlot;
1173 TupleTableSlot *slot;
1174 ItemPointer tupleid = NULL;
1175 ItemPointerData tuple_ctid;
1176 long current_tuple_count;
1177 TupleTableSlot *result;
1180 * initialize local variables
1182 current_tuple_count = 0;
1186 * Set the direction.
1188 estate->es_direction = direction;
1191 * Process BEFORE EACH STATEMENT triggers
1196 ExecBSUpdateTriggers(estate, estate->es_result_relation_info);
1199 ExecBSDeleteTriggers(estate, estate->es_result_relation_info);
1202 ExecBSInsertTriggers(estate, estate->es_result_relation_info);
1210 * Loop until we've processed the proper number of tuples from the plan.
1215 /* Reset the per-output-tuple exprcontext */
1216 ResetPerTupleExprContext(estate);
1219 * Execute the plan and obtain a tuple
1222 if (estate->es_useEvalPlan)
1224 planSlot = EvalPlanQualNext(estate);
1225 if (TupIsNull(planSlot))
1226 planSlot = ExecProcNode(planstate);
1229 planSlot = ExecProcNode(planstate);
1232 * if the tuple is null, then we assume there is nothing more to
1233 * process so we just return null...
1235 if (TupIsNull(planSlot))
1243 * if we have a junk filter, then project a new tuple with the junk
1246 * Store this new "clean" tuple in the junkfilter's resultSlot.
1247 * (Formerly, we stored it back over the "dirty" tuple, which is WRONG
1248 * because that tuple slot has the wrong descriptor.)
1250 * Also, extract all the junk information we need.
1252 if ((junkfilter = estate->es_junkFilter) != NULL)
1258 * extract the 'ctid' junk attribute.
1260 if (operation == CMD_UPDATE || operation == CMD_DELETE)
1262 datum = ExecGetJunkAttribute(slot, junkfilter->jf_junkAttNo,
1264 /* shouldn't ever get a null result... */
1266 elog(ERROR, "ctid is NULL");
1268 tupleid = (ItemPointer) DatumGetPointer(datum);
1269 tuple_ctid = *tupleid; /* make sure we don't free the ctid!! */
1270 tupleid = &tuple_ctid;
1274 * Process any FOR UPDATE or FOR SHARE locking requested.
1276 else if (estate->es_rowMarks != NIL)
1281 foreach(l, estate->es_rowMarks)
1283 ExecRowMark *erm = lfirst(l);
1284 HeapTupleData tuple;
1286 ItemPointerData update_ctid;
1287 TransactionId update_xmax;
1288 TupleTableSlot *newSlot;
1289 LockTupleMode lockmode;
1292 datum = ExecGetJunkAttribute(slot,
1295 /* shouldn't ever get a null result... */
1297 elog(ERROR, "ctid is NULL");
1299 tuple.t_self = *((ItemPointer) DatumGetPointer(datum));
1302 lockmode = LockTupleExclusive;
1304 lockmode = LockTupleShared;
1306 test = heap_lock_tuple(erm->relation, &tuple, &buffer,
1307 &update_ctid, &update_xmax,
1308 estate->es_output_cid,
1309 lockmode, erm->noWait);
1310 ReleaseBuffer(buffer);
1313 case HeapTupleSelfUpdated:
1314 /* treat it as deleted; do not process */
1317 case HeapTupleMayBeUpdated:
1320 case HeapTupleUpdated:
1321 if (IsXactIsoLevelSerializable)
1323 (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
1324 errmsg("could not serialize access due to concurrent update")));
1325 if (!ItemPointerEquals(&update_ctid,
1328 /* updated, so look at updated version */
1329 newSlot = EvalPlanQual(estate,
1333 if (!TupIsNull(newSlot))
1335 slot = planSlot = newSlot;
1336 estate->es_useEvalPlan = true;
1342 * if tuple was deleted or PlanQual failed for
1343 * updated tuple - we must not return this tuple!
1348 elog(ERROR, "unrecognized heap_lock_tuple status: %u",
1356 * Create a new "clean" tuple with all junk attributes removed. We
1357 * don't need to do this for DELETE, however (there will in fact
1358 * be no non-junk attributes in a DELETE!)
1360 if (operation != CMD_DELETE)
1361 slot = ExecFilterJunk(junkfilter, slot);
1365 * now that we have a tuple, do the appropriate thing with it.. either
1366 * return it to the user, add it to a relation someplace, delete it
1367 * from a relation, or modify some of its attributes.
1372 ExecSelect(slot, dest, estate);
1377 ExecInsert(slot, tupleid, planSlot, dest, estate);
1382 ExecDelete(tupleid, planSlot, dest, estate);
1387 ExecUpdate(slot, tupleid, planSlot, dest, estate);
1392 elog(ERROR, "unrecognized operation code: %d",
1399 * check our tuple count.. if we've processed the proper number then
1400 * quit, else loop again and process more tuples. Zero numberTuples
1403 current_tuple_count++;
1404 if (numberTuples && numberTuples == current_tuple_count)
1409 * Process AFTER EACH STATEMENT triggers
1414 ExecASUpdateTriggers(estate, estate->es_result_relation_info);
1417 ExecASDeleteTriggers(estate, estate->es_result_relation_info);
1420 ExecASInsertTriggers(estate, estate->es_result_relation_info);
1428 * here, result is either a slot containing a tuple in the case of a
1429 * SELECT or NULL otherwise.
1434 /* ----------------------------------------------------------------
1437 * SELECTs are easy.. we just pass the tuple to the appropriate
1439 * ----------------------------------------------------------------
1442 ExecSelect(TupleTableSlot *slot,
1446 (*dest->receiveSlot) (slot, dest);
1448 (estate->es_processed)++;
1451 /* ----------------------------------------------------------------
1454 * INSERTs are trickier.. we have to insert the tuple into
1455 * the base relation and insert appropriate tuples into the
1457 * ----------------------------------------------------------------
1460 ExecInsert(TupleTableSlot *slot,
1461 ItemPointer tupleid,
1462 TupleTableSlot *planSlot,
1467 ResultRelInfo *resultRelInfo;
1468 Relation resultRelationDesc;
1472 * get the heap tuple out of the tuple table slot, making sure we have a
1475 tuple = ExecMaterializeSlot(slot);
1478 * get information on the (current) result relation
1480 resultRelInfo = estate->es_result_relation_info;
1481 resultRelationDesc = resultRelInfo->ri_RelationDesc;
1483 /* BEFORE ROW INSERT Triggers */
1484 if (resultRelInfo->ri_TrigDesc &&
1485 resultRelInfo->ri_TrigDesc->n_before_row[TRIGGER_EVENT_INSERT] > 0)
1489 newtuple = ExecBRInsertTriggers(estate, resultRelInfo, tuple);
1491 if (newtuple == NULL) /* "do nothing" */
1494 if (newtuple != tuple) /* modified by Trigger(s) */
1497 * Put the modified tuple into a slot for convenience of routines
1498 * below. We assume the tuple was allocated in per-tuple memory
1499 * context, and therefore will go away by itself. The tuple table
1500 * slot should not try to clear it.
1502 TupleTableSlot *newslot = estate->es_trig_tuple_slot;
1504 if (newslot->tts_tupleDescriptor != slot->tts_tupleDescriptor)
1505 ExecSetSlotDescriptor(newslot, slot->tts_tupleDescriptor);
1506 ExecStoreTuple(newtuple, newslot, InvalidBuffer, false);
1513 * Check the constraints of the tuple
1515 if (resultRelationDesc->rd_att->constr)
1516 ExecConstraints(resultRelInfo, slot, estate);
1521 * Note: heap_insert returns the tid (location) of the new tuple in the
1524 newId = heap_insert(resultRelationDesc, tuple,
1525 estate->es_output_cid,
1529 (estate->es_processed)++;
1530 estate->es_lastoid = newId;
1531 setLastTid(&(tuple->t_self));
1534 * insert index entries for tuple
1536 if (resultRelInfo->ri_NumIndices > 0)
1537 ExecInsertIndexTuples(slot, &(tuple->t_self), estate, false);
1539 /* AFTER ROW INSERT Triggers */
1540 ExecARInsertTriggers(estate, resultRelInfo, tuple);
1542 /* Process RETURNING if present */
1543 if (resultRelInfo->ri_projectReturning)
1544 ExecProcessReturning(resultRelInfo->ri_projectReturning,
1545 slot, planSlot, dest);
1548 /* ----------------------------------------------------------------
1551 * DELETE is like UPDATE, except that we delete the tuple and no
1552 * index modifications are needed
1553 * ----------------------------------------------------------------
1556 ExecDelete(ItemPointer tupleid,
1557 TupleTableSlot *planSlot,
1561 ResultRelInfo *resultRelInfo;
1562 Relation resultRelationDesc;
1564 ItemPointerData update_ctid;
1565 TransactionId update_xmax;
1568 * get information on the (current) result relation
1570 resultRelInfo = estate->es_result_relation_info;
1571 resultRelationDesc = resultRelInfo->ri_RelationDesc;
1573 /* BEFORE ROW DELETE Triggers */
1574 if (resultRelInfo->ri_TrigDesc &&
1575 resultRelInfo->ri_TrigDesc->n_before_row[TRIGGER_EVENT_DELETE] > 0)
1579 dodelete = ExecBRDeleteTriggers(estate, resultRelInfo, tupleid);
1581 if (!dodelete) /* "do nothing" */
1588 * Note: if es_crosscheck_snapshot isn't InvalidSnapshot, we check that
1589 * the row to be deleted is visible to that snapshot, and throw a can't-
1590 * serialize error if not. This is a special-case behavior needed for
1591 * referential integrity updates in serializable transactions.
1594 result = heap_delete(resultRelationDesc, tupleid,
1595 &update_ctid, &update_xmax,
1596 estate->es_output_cid,
1597 estate->es_crosscheck_snapshot,
1598 true /* wait for commit */ );
1601 case HeapTupleSelfUpdated:
1602 /* already deleted by self; nothing to do */
1605 case HeapTupleMayBeUpdated:
1608 case HeapTupleUpdated:
1609 if (IsXactIsoLevelSerializable)
1611 (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
1612 errmsg("could not serialize access due to concurrent update")));
1613 else if (!ItemPointerEquals(tupleid, &update_ctid))
1615 TupleTableSlot *epqslot;
1617 epqslot = EvalPlanQual(estate,
1618 resultRelInfo->ri_RangeTableIndex,
1621 if (!TupIsNull(epqslot))
1623 *tupleid = update_ctid;
1627 /* tuple already deleted; nothing to do */
1631 elog(ERROR, "unrecognized heap_delete status: %u", result);
1636 (estate->es_processed)++;
1639 * Note: Normally one would think that we have to delete index tuples
1640 * associated with the heap tuple now...
1642 * ... but in POSTGRES, we have no need to do this because VACUUM will
1643 * take care of it later. We can't delete index tuples immediately
1644 * anyway, since the tuple is still visible to other transactions.
1647 /* AFTER ROW DELETE Triggers */
1648 ExecARDeleteTriggers(estate, resultRelInfo, tupleid);
1650 /* Process RETURNING if present */
1651 if (resultRelInfo->ri_projectReturning)
1654 * We have to put the target tuple into a slot, which means first we
1655 * gotta fetch it. We can use the trigger tuple slot.
1657 TupleTableSlot *slot = estate->es_trig_tuple_slot;
1658 HeapTupleData deltuple;
1661 deltuple.t_self = *tupleid;
1662 if (!heap_fetch(resultRelationDesc, SnapshotAny,
1663 &deltuple, &delbuffer, false, NULL))
1664 elog(ERROR, "failed to fetch deleted tuple for DELETE RETURNING");
1666 if (slot->tts_tupleDescriptor != RelationGetDescr(resultRelationDesc))
1667 ExecSetSlotDescriptor(slot, RelationGetDescr(resultRelationDesc));
1668 ExecStoreTuple(&deltuple, slot, InvalidBuffer, false);
1670 ExecProcessReturning(resultRelInfo->ri_projectReturning,
1671 slot, planSlot, dest);
1673 ExecClearTuple(slot);
1674 ReleaseBuffer(delbuffer);
1678 /* ----------------------------------------------------------------
1681 * note: we can't run UPDATE queries with transactions
1682 * off because UPDATEs are actually INSERTs and our
1683 * scan will mistakenly loop forever, updating the tuple
1684 * it just inserted.. This should be fixed but until it
1685 * is, we don't want to get stuck in an infinite loop
1686 * which corrupts your database..
1687 * ----------------------------------------------------------------
1690 ExecUpdate(TupleTableSlot *slot,
1691 ItemPointer tupleid,
1692 TupleTableSlot *planSlot,
1697 ResultRelInfo *resultRelInfo;
1698 Relation resultRelationDesc;
1700 ItemPointerData update_ctid;
1701 TransactionId update_xmax;
1704 * abort the operation if not running transactions
1706 if (IsBootstrapProcessingMode())
1707 elog(ERROR, "cannot UPDATE during bootstrap");
1710 * get the heap tuple out of the tuple table slot, making sure we have a
1713 tuple = ExecMaterializeSlot(slot);
1716 * get information on the (current) result relation
1718 resultRelInfo = estate->es_result_relation_info;
1719 resultRelationDesc = resultRelInfo->ri_RelationDesc;
1721 /* BEFORE ROW UPDATE Triggers */
1722 if (resultRelInfo->ri_TrigDesc &&
1723 resultRelInfo->ri_TrigDesc->n_before_row[TRIGGER_EVENT_UPDATE] > 0)
1727 newtuple = ExecBRUpdateTriggers(estate, resultRelInfo,
1730 if (newtuple == NULL) /* "do nothing" */
1733 if (newtuple != tuple) /* modified by Trigger(s) */
1736 * Put the modified tuple into a slot for convenience of routines
1737 * below. We assume the tuple was allocated in per-tuple memory
1738 * context, and therefore will go away by itself. The tuple table
1739 * slot should not try to clear it.
1741 TupleTableSlot *newslot = estate->es_trig_tuple_slot;
1743 if (newslot->tts_tupleDescriptor != slot->tts_tupleDescriptor)
1744 ExecSetSlotDescriptor(newslot, slot->tts_tupleDescriptor);
1745 ExecStoreTuple(newtuple, newslot, InvalidBuffer, false);
1752 * Check the constraints of the tuple
1754 * If we generate a new candidate tuple after EvalPlanQual testing, we
1755 * must loop back here and recheck constraints. (We don't need to redo
1756 * triggers, however. If there are any BEFORE triggers then trigger.c
1757 * will have done heap_lock_tuple to lock the correct tuple, so there's no
1758 * need to do them again.)
1761 if (resultRelationDesc->rd_att->constr)
1762 ExecConstraints(resultRelInfo, slot, estate);
1765 * replace the heap tuple
1767 * Note: if es_crosscheck_snapshot isn't InvalidSnapshot, we check that
1768 * the row to be updated is visible to that snapshot, and throw a can't-
1769 * serialize error if not. This is a special-case behavior needed for
1770 * referential integrity updates in serializable transactions.
1772 result = heap_update(resultRelationDesc, tupleid, tuple,
1773 &update_ctid, &update_xmax,
1774 estate->es_output_cid,
1775 estate->es_crosscheck_snapshot,
1776 true /* wait for commit */ );
1779 case HeapTupleSelfUpdated:
1780 /* already deleted by self; nothing to do */
1783 case HeapTupleMayBeUpdated:
1786 case HeapTupleUpdated:
1787 if (IsXactIsoLevelSerializable)
1789 (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
1790 errmsg("could not serialize access due to concurrent update")));
1791 else if (!ItemPointerEquals(tupleid, &update_ctid))
1793 TupleTableSlot *epqslot;
1795 epqslot = EvalPlanQual(estate,
1796 resultRelInfo->ri_RangeTableIndex,
1799 if (!TupIsNull(epqslot))
1801 *tupleid = update_ctid;
1802 slot = ExecFilterJunk(estate->es_junkFilter, epqslot);
1803 tuple = ExecMaterializeSlot(slot);
1807 /* tuple already deleted; nothing to do */
1811 elog(ERROR, "unrecognized heap_update status: %u", result);
1816 (estate->es_processed)++;
1819 * Note: instead of having to update the old index tuples associated with
1820 * the heap tuple, all we do is form and insert new index tuples. This is
1821 * because UPDATEs are actually DELETEs and INSERTs, and index tuple
1822 * deletion is done later by VACUUM (see notes in ExecDelete). All we do
1823 * here is insert new index tuples. -cim 9/27/89
1827 * insert index entries for tuple
1829 * Note: heap_update returns the tid (location) of the new tuple in the
1832 * If it's a HOT update, we mustn't insert new index entries.
1834 if (resultRelInfo->ri_NumIndices > 0 && !HeapTupleIsHeapOnly(tuple))
1835 ExecInsertIndexTuples(slot, &(tuple->t_self), estate, false);
1837 /* AFTER ROW UPDATE Triggers */
1838 ExecARUpdateTriggers(estate, resultRelInfo, tupleid, tuple);
1840 /* Process RETURNING if present */
1841 if (resultRelInfo->ri_projectReturning)
1842 ExecProcessReturning(resultRelInfo->ri_projectReturning,
1843 slot, planSlot, dest);
1847 * ExecRelCheck --- check that tuple meets constraints for result relation
1850 ExecRelCheck(ResultRelInfo *resultRelInfo,
1851 TupleTableSlot *slot, EState *estate)
1853 Relation rel = resultRelInfo->ri_RelationDesc;
1854 int ncheck = rel->rd_att->constr->num_check;
1855 ConstrCheck *check = rel->rd_att->constr->check;
1856 ExprContext *econtext;
1857 MemoryContext oldContext;
1862 * If first time through for this result relation, build expression
1863 * nodetrees for rel's constraint expressions. Keep them in the per-query
1864 * memory context so they'll survive throughout the query.
1866 if (resultRelInfo->ri_ConstraintExprs == NULL)
1868 oldContext = MemoryContextSwitchTo(estate->es_query_cxt);
1869 resultRelInfo->ri_ConstraintExprs =
1870 (List **) palloc(ncheck * sizeof(List *));
1871 for (i = 0; i < ncheck; i++)
1873 /* ExecQual wants implicit-AND form */
1874 qual = make_ands_implicit(stringToNode(check[i].ccbin));
1875 resultRelInfo->ri_ConstraintExprs[i] = (List *)
1876 ExecPrepareExpr((Expr *) qual, estate);
1878 MemoryContextSwitchTo(oldContext);
1882 * We will use the EState's per-tuple context for evaluating constraint
1883 * expressions (creating it if it's not already there).
1885 econtext = GetPerTupleExprContext(estate);
1887 /* Arrange for econtext's scan tuple to be the tuple under test */
1888 econtext->ecxt_scantuple = slot;
1890 /* And evaluate the constraints */
1891 for (i = 0; i < ncheck; i++)
1893 qual = resultRelInfo->ri_ConstraintExprs[i];
1896 * NOTE: SQL92 specifies that a NULL result from a constraint
1897 * expression is not to be treated as a failure. Therefore, tell
1898 * ExecQual to return TRUE for NULL.
1900 if (!ExecQual(qual, econtext, true))
1901 return check[i].ccname;
1904 /* NULL result means no error */
1909 ExecConstraints(ResultRelInfo *resultRelInfo,
1910 TupleTableSlot *slot, EState *estate)
1912 Relation rel = resultRelInfo->ri_RelationDesc;
1913 TupleConstr *constr = rel->rd_att->constr;
1917 if (constr->has_not_null)
1919 int natts = rel->rd_att->natts;
1922 for (attrChk = 1; attrChk <= natts; attrChk++)
1924 if (rel->rd_att->attrs[attrChk - 1]->attnotnull &&
1925 slot_attisnull(slot, attrChk))
1927 (errcode(ERRCODE_NOT_NULL_VIOLATION),
1928 errmsg("null value in column \"%s\" violates not-null constraint",
1929 NameStr(rel->rd_att->attrs[attrChk - 1]->attname))));
1933 if (constr->num_check > 0)
1937 if ((failed = ExecRelCheck(resultRelInfo, slot, estate)) != NULL)
1939 (errcode(ERRCODE_CHECK_VIOLATION),
1940 errmsg("new row for relation \"%s\" violates check constraint \"%s\"",
1941 RelationGetRelationName(rel), failed)));
1946 * ExecProcessReturning --- evaluate a RETURNING list and send to dest
1948 * projectReturning: RETURNING projection info for current result rel
1949 * tupleSlot: slot holding tuple actually inserted/updated/deleted
1950 * planSlot: slot holding tuple returned by top plan node
1951 * dest: where to send the output
1954 ExecProcessReturning(ProjectionInfo *projectReturning,
1955 TupleTableSlot *tupleSlot,
1956 TupleTableSlot *planSlot,
1959 ExprContext *econtext = projectReturning->pi_exprContext;
1960 TupleTableSlot *retSlot;
1963 * Reset per-tuple memory context to free any expression evaluation
1964 * storage allocated in the previous cycle.
1966 ResetExprContext(econtext);
1968 /* Make tuple and any needed join variables available to ExecProject */
1969 econtext->ecxt_scantuple = tupleSlot;
1970 econtext->ecxt_outertuple = planSlot;
1972 /* Compute the RETURNING expressions */
1973 retSlot = ExecProject(projectReturning, NULL);
1976 (*dest->receiveSlot) (retSlot, dest);
1978 ExecClearTuple(retSlot);
1982 * Check a modified tuple to see if we want to process its updated version
1983 * under READ COMMITTED rules.
1985 * See backend/executor/README for some info about how this works.
1987 * estate - executor state data
1988 * rti - rangetable index of table containing tuple
1989 * *tid - t_ctid from the outdated tuple (ie, next updated version)
1990 * priorXmax - t_xmax from the outdated tuple
1992 * *tid is also an output parameter: it's modified to hold the TID of the
1993 * latest version of the tuple (note this may be changed even on failure)
1995 * Returns a slot containing the new candidate update/delete tuple, or
1996 * NULL if we determine we shouldn't process the row.
1999 EvalPlanQual(EState *estate, Index rti,
2000 ItemPointer tid, TransactionId priorXmax)
2005 HeapTupleData tuple;
2006 HeapTuple copyTuple = NULL;
2007 SnapshotData SnapshotDirty;
2013 * find relation containing target tuple
2015 if (estate->es_result_relation_info != NULL &&
2016 estate->es_result_relation_info->ri_RangeTableIndex == rti)
2017 relation = estate->es_result_relation_info->ri_RelationDesc;
2023 foreach(l, estate->es_rowMarks)
2025 if (((ExecRowMark *) lfirst(l))->rti == rti)
2027 relation = ((ExecRowMark *) lfirst(l))->relation;
2031 if (relation == NULL)
2032 elog(ERROR, "could not find RowMark for RT index %u", rti);
2038 * Loop here to deal with updated or busy tuples
2040 InitDirtySnapshot(SnapshotDirty);
2041 tuple.t_self = *tid;
2046 if (heap_fetch(relation, &SnapshotDirty, &tuple, &buffer, true, NULL))
2049 * If xmin isn't what we're expecting, the slot must have been
2050 * recycled and reused for an unrelated tuple. This implies that
2051 * the latest version of the row was deleted, so we need do
2052 * nothing. (Should be safe to examine xmin without getting
2053 * buffer's content lock, since xmin never changes in an existing
2056 if (!TransactionIdEquals(HeapTupleHeaderGetXmin(tuple.t_data),
2059 ReleaseBuffer(buffer);
2063 /* otherwise xmin should not be dirty... */
2064 if (TransactionIdIsValid(SnapshotDirty.xmin))
2065 elog(ERROR, "t_xmin is uncommitted in tuple to be updated");
2068 * If tuple is being updated by other transaction then we have to
2069 * wait for its commit/abort.
2071 if (TransactionIdIsValid(SnapshotDirty.xmax))
2073 ReleaseBuffer(buffer);
2074 XactLockTableWait(SnapshotDirty.xmax);
2075 continue; /* loop back to repeat heap_fetch */
2079 * If tuple was inserted by our own transaction, we have to check
2080 * cmin against es_output_cid: cmin >= current CID means our
2081 * command cannot see the tuple, so we should ignore it. Without
2082 * this we are open to the "Halloween problem" of indefinitely
2083 * re-updating the same tuple. (We need not check cmax because
2084 * HeapTupleSatisfiesDirty will consider a tuple deleted by our
2085 * transaction dead, regardless of cmax.) We just checked that
2086 * priorXmax == xmin, so we can test that variable instead of
2087 * doing HeapTupleHeaderGetXmin again.
2089 if (TransactionIdIsCurrentTransactionId(priorXmax) &&
2090 HeapTupleHeaderGetCmin(tuple.t_data) >= estate->es_output_cid)
2092 ReleaseBuffer(buffer);
2097 * We got tuple - now copy it for use by recheck query.
2099 copyTuple = heap_copytuple(&tuple);
2100 ReleaseBuffer(buffer);
2105 * If the referenced slot was actually empty, the latest version of
2106 * the row must have been deleted, so we need do nothing.
2108 if (tuple.t_data == NULL)
2110 ReleaseBuffer(buffer);
2115 * As above, if xmin isn't what we're expecting, do nothing.
2117 if (!TransactionIdEquals(HeapTupleHeaderGetXmin(tuple.t_data),
2120 ReleaseBuffer(buffer);
2125 * If we get here, the tuple was found but failed SnapshotDirty.
2126 * Assuming the xmin is either a committed xact or our own xact (as it
2127 * certainly should be if we're trying to modify the tuple), this must
2128 * mean that the row was updated or deleted by either a committed xact
2129 * or our own xact. If it was deleted, we can ignore it; if it was
2130 * updated then chain up to the next version and repeat the whole
2133 * As above, it should be safe to examine xmax and t_ctid without the
2134 * buffer content lock, because they can't be changing.
2136 if (ItemPointerEquals(&tuple.t_self, &tuple.t_data->t_ctid))
2138 /* deleted, so forget about it */
2139 ReleaseBuffer(buffer);
2143 /* updated, so look at the updated row */
2144 tuple.t_self = tuple.t_data->t_ctid;
2145 /* updated row should have xmin matching this xmax */
2146 priorXmax = HeapTupleHeaderGetXmax(tuple.t_data);
2147 ReleaseBuffer(buffer);
2148 /* loop back to fetch next in chain */
2152 * For UPDATE/DELETE we have to return tid of actual row we're executing
2155 *tid = tuple.t_self;
2158 * Need to run a recheck subquery. Find or create a PQ stack entry.
2160 epq = estate->es_evalPlanQual;
2163 if (epq != NULL && epq->rti == 0)
2165 /* Top PQ stack entry is idle, so re-use it */
2166 Assert(!(estate->es_useEvalPlan) && epq->next == NULL);
2172 * If this is request for another RTE - Ra, - then we have to check wasn't
2173 * PlanQual requested for Ra already and if so then Ra' row was updated
2174 * again and we have to re-start old execution for Ra and forget all what
2175 * we done after Ra was suspended. Cool? -:))
2177 if (epq != NULL && epq->rti != rti &&
2178 epq->estate->es_evTuple[rti - 1] != NULL)
2182 evalPlanQual *oldepq;
2184 /* stop execution */
2185 EvalPlanQualStop(epq);
2186 /* pop previous PlanQual from the stack */
2188 Assert(oldepq && oldepq->rti != 0);
2189 /* push current PQ to freePQ stack */
2192 estate->es_evalPlanQual = epq;
2193 } while (epq->rti != rti);
2197 * If we are requested for another RTE then we have to suspend execution
2198 * of current PlanQual and start execution for new one.
2200 if (epq == NULL || epq->rti != rti)
2202 /* try to reuse plan used previously */
2203 evalPlanQual *newepq = (epq != NULL) ? epq->free : NULL;
2205 if (newepq == NULL) /* first call or freePQ stack is empty */
2207 newepq = (evalPlanQual *) palloc0(sizeof(evalPlanQual));
2208 newepq->free = NULL;
2209 newepq->estate = NULL;
2210 newepq->planstate = NULL;
2214 /* recycle previously used PlanQual */
2215 Assert(newepq->estate == NULL);
2218 /* push current PQ to the stack */
2221 estate->es_evalPlanQual = epq;
2226 Assert(epq->rti == rti);
2229 * Ok - we're requested for the same RTE. Unfortunately we still have to
2230 * end and restart execution of the plan, because ExecReScan wouldn't
2231 * ensure that upper plan nodes would reset themselves. We could make
2232 * that work if insertion of the target tuple were integrated with the
2233 * Param mechanism somehow, so that the upper plan nodes know that their
2234 * children's outputs have changed.
2236 * Note that the stack of free evalPlanQual nodes is quite useless at the
2237 * moment, since it only saves us from pallocing/releasing the
2238 * evalPlanQual nodes themselves. But it will be useful once we implement
2239 * ReScan instead of end/restart for re-using PlanQual nodes.
2243 /* stop execution */
2244 EvalPlanQualStop(epq);
2248 * Initialize new recheck query.
2250 * Note: if we were re-using PlanQual plans via ExecReScan, we'd need to
2251 * instead copy down changeable state from the top plan (including
2252 * es_result_relation_info, es_junkFilter) and reset locally changeable
2253 * state in the epq (including es_param_exec_vals, es_evTupleNull).
2255 EvalPlanQualStart(epq, estate, epq->next);
2258 * free old RTE' tuple, if any, and store target tuple where relation's
2259 * scan node will see it
2261 epqstate = epq->estate;
2262 if (epqstate->es_evTuple[rti - 1] != NULL)
2263 heap_freetuple(epqstate->es_evTuple[rti - 1]);
2264 epqstate->es_evTuple[rti - 1] = copyTuple;
2266 return EvalPlanQualNext(estate);
2269 static TupleTableSlot *
2270 EvalPlanQualNext(EState *estate)
2272 evalPlanQual *epq = estate->es_evalPlanQual;
2273 MemoryContext oldcontext;
2274 TupleTableSlot *slot;
2276 Assert(epq->rti != 0);
2279 oldcontext = MemoryContextSwitchTo(epq->estate->es_query_cxt);
2280 slot = ExecProcNode(epq->planstate);
2281 MemoryContextSwitchTo(oldcontext);
2284 * No more tuples for this PQ. Continue previous one.
2286 if (TupIsNull(slot))
2288 evalPlanQual *oldepq;
2290 /* stop execution */
2291 EvalPlanQualStop(epq);
2292 /* pop old PQ from the stack */
2296 /* this is the first (oldest) PQ - mark as free */
2298 estate->es_useEvalPlan = false;
2299 /* and continue Query execution */
2302 Assert(oldepq->rti != 0);
2303 /* push current PQ to freePQ stack */
2306 estate->es_evalPlanQual = epq;
2314 EndEvalPlanQual(EState *estate)
2316 evalPlanQual *epq = estate->es_evalPlanQual;
2318 if (epq->rti == 0) /* plans already shutdowned */
2320 Assert(epq->next == NULL);
2326 evalPlanQual *oldepq;
2328 /* stop execution */
2329 EvalPlanQualStop(epq);
2330 /* pop old PQ from the stack */
2334 /* this is the first (oldest) PQ - mark as free */
2336 estate->es_useEvalPlan = false;
2339 Assert(oldepq->rti != 0);
2340 /* push current PQ to freePQ stack */
2343 estate->es_evalPlanQual = epq;
2348 * Start execution of one level of PlanQual.
2350 * This is a cut-down version of ExecutorStart(): we copy some state from
2351 * the top-level estate rather than initializing it fresh.
2354 EvalPlanQualStart(evalPlanQual *epq, EState *estate, evalPlanQual *priorepq)
2358 MemoryContext oldcontext;
2361 rtsize = list_length(estate->es_range_table);
2363 epq->estate = epqstate = CreateExecutorState();
2365 oldcontext = MemoryContextSwitchTo(epqstate->es_query_cxt);
2368 * The epqstates share the top query's copy of unchanging state such as
2369 * the snapshot, rangetable, result-rel info, and external Param info.
2370 * They need their own copies of local state, including a tuple table,
2371 * es_param_exec_vals, etc.
2373 epqstate->es_direction = ForwardScanDirection;
2374 epqstate->es_snapshot = estate->es_snapshot;
2375 epqstate->es_crosscheck_snapshot = estate->es_crosscheck_snapshot;
2376 epqstate->es_range_table = estate->es_range_table;
2377 epqstate->es_output_cid = estate->es_output_cid;
2378 epqstate->es_result_relations = estate->es_result_relations;
2379 epqstate->es_num_result_relations = estate->es_num_result_relations;
2380 epqstate->es_result_relation_info = estate->es_result_relation_info;
2381 epqstate->es_junkFilter = estate->es_junkFilter;
2382 /* es_trig_target_relations must NOT be copied */
2383 epqstate->es_into_relation_descriptor = estate->es_into_relation_descriptor;
2384 epqstate->es_into_relation_use_wal = estate->es_into_relation_use_wal;
2385 epqstate->es_param_list_info = estate->es_param_list_info;
2386 if (estate->es_plannedstmt->nParamExec > 0)
2387 epqstate->es_param_exec_vals = (ParamExecData *)
2388 palloc0(estate->es_plannedstmt->nParamExec * sizeof(ParamExecData));
2389 epqstate->es_rowMarks = estate->es_rowMarks;
2390 epqstate->es_instrument = estate->es_instrument;
2391 epqstate->es_select_into = estate->es_select_into;
2392 epqstate->es_into_oids = estate->es_into_oids;
2393 epqstate->es_plannedstmt = estate->es_plannedstmt;
2396 * Each epqstate must have its own es_evTupleNull state, but all the stack
2397 * entries share es_evTuple state. This allows sub-rechecks to inherit
2398 * the value being examined by an outer recheck.
2400 epqstate->es_evTupleNull = (bool *) palloc0(rtsize * sizeof(bool));
2401 if (priorepq == NULL)
2402 /* first PQ stack entry */
2403 epqstate->es_evTuple = (HeapTuple *)
2404 palloc0(rtsize * sizeof(HeapTuple));
2406 /* later stack entries share the same storage */
2407 epqstate->es_evTuple = priorepq->estate->es_evTuple;
2410 * Create sub-tuple-table; we needn't redo the CountSlots work though.
2412 epqstate->es_tupleTable =
2413 ExecCreateTupleTable(estate->es_tupleTable->size);
2416 * Initialize private state information for each SubPlan. We must do this
2417 * before running ExecInitNode on the main query tree, since
2418 * ExecInitSubPlan expects to be able to find these entries.
2420 Assert(epqstate->es_subplanstates == NIL);
2421 foreach(l, estate->es_plannedstmt->subplans)
2423 Plan *subplan = (Plan *) lfirst(l);
2424 PlanState *subplanstate;
2426 subplanstate = ExecInitNode(subplan, epqstate, 0);
2428 epqstate->es_subplanstates = lappend(epqstate->es_subplanstates,
2433 * Initialize the private state information for all the nodes in the query
2434 * tree. This opens files, allocates storage and leaves us ready to start
2435 * processing tuples.
2437 epq->planstate = ExecInitNode(estate->es_plannedstmt->planTree, epqstate, 0);
2439 MemoryContextSwitchTo(oldcontext);
2443 * End execution of one level of PlanQual.
2445 * This is a cut-down version of ExecutorEnd(); basically we want to do most
2446 * of the normal cleanup, but *not* close result relations (which we are
2447 * just sharing from the outer query). We do, however, have to close any
2448 * trigger target relations that got opened, since those are not shared.
2451 EvalPlanQualStop(evalPlanQual *epq)
2453 EState *epqstate = epq->estate;
2454 MemoryContext oldcontext;
2457 oldcontext = MemoryContextSwitchTo(epqstate->es_query_cxt);
2459 ExecEndNode(epq->planstate);
2461 foreach(l, epqstate->es_subplanstates)
2463 PlanState *subplanstate = (PlanState *) lfirst(l);
2465 ExecEndNode(subplanstate);
2468 ExecDropTupleTable(epqstate->es_tupleTable, true);
2469 epqstate->es_tupleTable = NULL;
2471 if (epqstate->es_evTuple[epq->rti - 1] != NULL)
2473 heap_freetuple(epqstate->es_evTuple[epq->rti - 1]);
2474 epqstate->es_evTuple[epq->rti - 1] = NULL;
2477 foreach(l, epqstate->es_trig_target_relations)
2479 ResultRelInfo *resultRelInfo = (ResultRelInfo *) lfirst(l);
2481 /* Close indices and then the relation itself */
2482 ExecCloseIndices(resultRelInfo);
2483 heap_close(resultRelInfo->ri_RelationDesc, NoLock);
2486 MemoryContextSwitchTo(oldcontext);
2488 FreeExecutorState(epqstate);
2491 epq->planstate = NULL;
2495 * ExecGetActivePlanTree --- get the active PlanState tree from a QueryDesc
2497 * Ordinarily this is just the one mentioned in the QueryDesc, but if we
2498 * are looking at a row returned by the EvalPlanQual machinery, we need
2499 * to look at the subsidiary state instead.
2502 ExecGetActivePlanTree(QueryDesc *queryDesc)
2504 EState *estate = queryDesc->estate;
2506 if (estate && estate->es_useEvalPlan && estate->es_evalPlanQual != NULL)
2507 return estate->es_evalPlanQual->planstate;
2509 return queryDesc->planstate;
2514 * Support for SELECT INTO (a/k/a CREATE TABLE AS)
2516 * We implement SELECT INTO by diverting SELECT's normal output with
2517 * a specialized DestReceiver type.
2519 * TODO: remove some of the INTO-specific cruft from EState, and keep
2520 * it in the DestReceiver instead.
2525 DestReceiver pub; /* publicly-known function pointers */
2526 EState *estate; /* EState we are working with */
2530 * OpenIntoRel --- actually create the SELECT INTO target relation
2532 * This also replaces QueryDesc->dest with the special DestReceiver for
2533 * SELECT INTO. We assume that the correct result tuple type has already
2534 * been placed in queryDesc->tupDesc.
2537 OpenIntoRel(QueryDesc *queryDesc)
2539 IntoClause *into = queryDesc->plannedstmt->intoClause;
2540 EState *estate = queryDesc->estate;
2541 Relation intoRelationDesc;
2546 AclResult aclresult;
2549 DR_intorel *myState;
2554 * Check consistency of arguments
2556 if (into->onCommit != ONCOMMIT_NOOP && !into->rel->istemp)
2558 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
2559 errmsg("ON COMMIT can only be used on temporary tables")));
2562 * Find namespace to create in, check its permissions
2564 intoName = into->rel->relname;
2565 namespaceId = RangeVarGetCreationNamespace(into->rel);
2567 aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(),
2569 if (aclresult != ACLCHECK_OK)
2570 aclcheck_error(aclresult, ACL_KIND_NAMESPACE,
2571 get_namespace_name(namespaceId));
2574 * Select tablespace to use. If not specified, use default tablespace
2575 * (which may in turn default to database's default).
2577 if (into->tableSpaceName)
2579 tablespaceId = get_tablespace_oid(into->tableSpaceName);
2580 if (!OidIsValid(tablespaceId))
2582 (errcode(ERRCODE_UNDEFINED_OBJECT),
2583 errmsg("tablespace \"%s\" does not exist",
2584 into->tableSpaceName)));
2588 tablespaceId = GetDefaultTablespace(into->rel->istemp);
2589 /* note InvalidOid is OK in this case */
2592 /* Check permissions except when using the database's default space */
2593 if (OidIsValid(tablespaceId) && tablespaceId != MyDatabaseTableSpace)
2595 AclResult aclresult;
2597 aclresult = pg_tablespace_aclcheck(tablespaceId, GetUserId(),
2600 if (aclresult != ACLCHECK_OK)
2601 aclcheck_error(aclresult, ACL_KIND_TABLESPACE,
2602 get_tablespace_name(tablespaceId));
2605 /* Parse and validate any reloptions */
2606 reloptions = transformRelOptions((Datum) 0,
2610 (void) heap_reloptions(RELKIND_RELATION, reloptions, true);
2612 /* have to copy the actual tupdesc to get rid of any constraints */
2613 tupdesc = CreateTupleDescCopy(queryDesc->tupDesc);
2615 /* Now we can actually create the new relation */
2616 intoRelationId = heap_create_with_catalog(intoName,
2628 allowSystemTableMods);
2630 FreeTupleDesc(tupdesc);
2633 * Advance command counter so that the newly-created relation's catalog
2634 * tuples will be visible to heap_open.
2636 CommandCounterIncrement();
2639 * If necessary, create a TOAST table for the INTO relation. Note that
2640 * AlterTableCreateToastTable ends with CommandCounterIncrement(), so that
2641 * the TOAST table will be visible for insertion.
2643 AlterTableCreateToastTable(intoRelationId);
2646 * And open the constructed table for writing.
2648 intoRelationDesc = heap_open(intoRelationId, AccessExclusiveLock);
2650 /* use_wal off requires rd_targblock be initially invalid */
2651 Assert(intoRelationDesc->rd_targblock == InvalidBlockNumber);
2654 * We can skip WAL-logging the insertions, unless PITR is in use.
2656 estate->es_into_relation_use_wal = XLogArchivingActive();
2657 estate->es_into_relation_descriptor = intoRelationDesc;
2660 * Now replace the query's DestReceiver with one for SELECT INTO
2662 queryDesc->dest = CreateDestReceiver(DestIntoRel, NULL);
2663 myState = (DR_intorel *) queryDesc->dest;
2664 Assert(myState->pub.mydest == DestIntoRel);
2665 myState->estate = estate;
2669 * CloseIntoRel --- clean up SELECT INTO at ExecutorEnd time
2672 CloseIntoRel(QueryDesc *queryDesc)
2674 EState *estate = queryDesc->estate;
2676 /* OpenIntoRel might never have gotten called */
2677 if (estate->es_into_relation_descriptor)
2679 /* If we skipped using WAL, must heap_sync before commit */
2680 if (!estate->es_into_relation_use_wal)
2681 heap_sync(estate->es_into_relation_descriptor);
2683 /* close rel, but keep lock until commit */
2684 heap_close(estate->es_into_relation_descriptor, NoLock);
2686 estate->es_into_relation_descriptor = NULL;
2691 * CreateIntoRelDestReceiver -- create a suitable DestReceiver object
2693 * Since CreateDestReceiver doesn't accept the parameters we'd need,
2694 * we just leave the private fields empty here. OpenIntoRel will
2698 CreateIntoRelDestReceiver(void)
2700 DR_intorel *self = (DR_intorel *) palloc(sizeof(DR_intorel));
2702 self->pub.receiveSlot = intorel_receive;
2703 self->pub.rStartup = intorel_startup;
2704 self->pub.rShutdown = intorel_shutdown;
2705 self->pub.rDestroy = intorel_destroy;
2706 self->pub.mydest = DestIntoRel;
2708 self->estate = NULL;
2710 return (DestReceiver *) self;
2714 * intorel_startup --- executor startup
2717 intorel_startup(DestReceiver *self, int operation, TupleDesc typeinfo)
2723 * intorel_receive --- receive one tuple
2726 intorel_receive(TupleTableSlot *slot, DestReceiver *self)
2728 DR_intorel *myState = (DR_intorel *) self;
2729 EState *estate = myState->estate;
2732 tuple = ExecCopySlotTuple(slot);
2734 heap_insert(estate->es_into_relation_descriptor,
2736 estate->es_output_cid,
2737 estate->es_into_relation_use_wal,
2738 false); /* never any point in using FSM */
2740 /* We know this is a newly created relation, so there are no indexes */
2742 heap_freetuple(tuple);
2748 * intorel_shutdown --- executor end
2751 intorel_shutdown(DestReceiver *self)
2757 * intorel_destroy --- release DestReceiver object
2760 intorel_destroy(DestReceiver *self)