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https://github.com/postgres/postgres.git
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Move functions related to index maintenance to separate source file.
There is enough code here to deserve a file of their own, not be buried in the middle of execUtils.c.
This commit is contained in:
Heikki Linnakangas
parent
2c47fe16a7
commit
62420ae7d6
@ -12,8 +12,8 @@ subdir = src/backend/executor
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top_builddir = ../../..
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include $(top_builddir)/src/Makefile.global
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OBJS = execAmi.o execCurrent.o execGrouping.o execJunk.o execMain.o \
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execProcnode.o execQual.o execScan.o execTuples.o \
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OBJS = execAmi.o execCurrent.o execGrouping.o execIndexing.o execJunk.o \
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execMain.o execProcnode.o execQual.o execScan.o execTuples.o \
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execUtils.o functions.o instrument.o nodeAppend.o nodeAgg.o \
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nodeBitmapAnd.o nodeBitmapOr.o \
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nodeBitmapHeapscan.o nodeBitmapIndexscan.o nodeCustom.o nodeHash.o \
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541
src/backend/executor/execIndexing.c
Normal file
541
src/backend/executor/execIndexing.c
Normal file
@ -0,0 +1,541 @@
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/*-------------------------------------------------------------------------
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*
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* execIndexing.c
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* executor support for maintaining indexes
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*
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* Portions Copyright (c) 1996-2015, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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*
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* IDENTIFICATION
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* src/backend/executor/execIndexing.c
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include "access/relscan.h"
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#include "catalog/index.h"
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#include "executor/executor.h"
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#include "nodes/nodeFuncs.h"
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#include "storage/lmgr.h"
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#include "utils/tqual.h"
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static bool index_recheck_constraint(Relation index, Oid *constr_procs,
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Datum *existing_values, bool *existing_isnull,
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Datum *new_values);
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/* ----------------------------------------------------------------
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* ExecOpenIndices
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*
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* Find the indices associated with a result relation, open them,
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* and save information about them in the result ResultRelInfo.
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*
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* At entry, caller has already opened and locked
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* resultRelInfo->ri_RelationDesc.
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* ----------------------------------------------------------------
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*/
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void
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ExecOpenIndices(ResultRelInfo *resultRelInfo)
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{
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Relation resultRelation = resultRelInfo->ri_RelationDesc;
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List *indexoidlist;
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ListCell *l;
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int len,
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i;
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RelationPtr relationDescs;
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IndexInfo **indexInfoArray;
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resultRelInfo->ri_NumIndices = 0;
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/* fast path if no indexes */
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if (!RelationGetForm(resultRelation)->relhasindex)
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return;
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/*
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* Get cached list of index OIDs
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*/
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indexoidlist = RelationGetIndexList(resultRelation);
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len = list_length(indexoidlist);
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if (len == 0)
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return;
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/*
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* allocate space for result arrays
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*/
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relationDescs = (RelationPtr) palloc(len * sizeof(Relation));
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indexInfoArray = (IndexInfo **) palloc(len * sizeof(IndexInfo *));
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resultRelInfo->ri_NumIndices = len;
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resultRelInfo->ri_IndexRelationDescs = relationDescs;
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resultRelInfo->ri_IndexRelationInfo = indexInfoArray;
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/*
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* For each index, open the index relation and save pg_index info. We
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* acquire RowExclusiveLock, signifying we will update the index.
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*
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* Note: we do this even if the index is not IndexIsReady; it's not worth
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* the trouble to optimize for the case where it isn't.
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*/
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i = 0;
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foreach(l, indexoidlist)
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{
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Oid indexOid = lfirst_oid(l);
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Relation indexDesc;
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IndexInfo *ii;
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indexDesc = index_open(indexOid, RowExclusiveLock);
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/* extract index key information from the index's pg_index info */
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ii = BuildIndexInfo(indexDesc);
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relationDescs[i] = indexDesc;
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indexInfoArray[i] = ii;
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i++;
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}
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list_free(indexoidlist);
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}
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/* ----------------------------------------------------------------
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* ExecCloseIndices
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*
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* Close the index relations stored in resultRelInfo
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* ----------------------------------------------------------------
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*/
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void
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ExecCloseIndices(ResultRelInfo *resultRelInfo)
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{
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int i;
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int numIndices;
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RelationPtr indexDescs;
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numIndices = resultRelInfo->ri_NumIndices;
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indexDescs = resultRelInfo->ri_IndexRelationDescs;
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for (i = 0; i < numIndices; i++)
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{
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if (indexDescs[i] == NULL)
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continue; /* shouldn't happen? */
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/* Drop lock acquired by ExecOpenIndices */
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index_close(indexDescs[i], RowExclusiveLock);
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}
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/*
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* XXX should free indexInfo array here too? Currently we assume that
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* such stuff will be cleaned up automatically in FreeExecutorState.
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*/
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}
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/* ----------------------------------------------------------------
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* ExecInsertIndexTuples
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*
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* This routine takes care of inserting index tuples
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* into all the relations indexing the result relation
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* when a heap tuple is inserted into the result relation.
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* Much of this code should be moved into the genam
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* stuff as it only exists here because the genam stuff
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* doesn't provide the functionality needed by the
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* executor.. -cim 9/27/89
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*
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* This returns a list of index OIDs for any unique or exclusion
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* constraints that are deferred and that had
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* potential (unconfirmed) conflicts.
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*
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* CAUTION: this must not be called for a HOT update.
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* We can't defend against that here for lack of info.
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* Should we change the API to make it safer?
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* ----------------------------------------------------------------
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*/
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List *
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ExecInsertIndexTuples(TupleTableSlot *slot,
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ItemPointer tupleid,
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EState *estate)
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{
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List *result = NIL;
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ResultRelInfo *resultRelInfo;
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int i;
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int numIndices;
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RelationPtr relationDescs;
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Relation heapRelation;
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IndexInfo **indexInfoArray;
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ExprContext *econtext;
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Datum values[INDEX_MAX_KEYS];
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bool isnull[INDEX_MAX_KEYS];
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/*
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* Get information from the result relation info structure.
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*/
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resultRelInfo = estate->es_result_relation_info;
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numIndices = resultRelInfo->ri_NumIndices;
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relationDescs = resultRelInfo->ri_IndexRelationDescs;
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indexInfoArray = resultRelInfo->ri_IndexRelationInfo;
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heapRelation = resultRelInfo->ri_RelationDesc;
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/*
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* We will use the EState's per-tuple context for evaluating predicates
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* and index expressions (creating it if it's not already there).
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*/
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econtext = GetPerTupleExprContext(estate);
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/* Arrange for econtext's scan tuple to be the tuple under test */
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econtext->ecxt_scantuple = slot;
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/*
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* for each index, form and insert the index tuple
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*/
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for (i = 0; i < numIndices; i++)
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{
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Relation indexRelation = relationDescs[i];
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IndexInfo *indexInfo;
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IndexUniqueCheck checkUnique;
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bool satisfiesConstraint;
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if (indexRelation == NULL)
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continue;
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indexInfo = indexInfoArray[i];
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/* If the index is marked as read-only, ignore it */
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if (!indexInfo->ii_ReadyForInserts)
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continue;
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/* Check for partial index */
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if (indexInfo->ii_Predicate != NIL)
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{
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List *predicate;
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/*
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* If predicate state not set up yet, create it (in the estate's
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* per-query context)
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*/
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predicate = indexInfo->ii_PredicateState;
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if (predicate == NIL)
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{
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predicate = (List *)
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ExecPrepareExpr((Expr *) indexInfo->ii_Predicate,
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estate);
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indexInfo->ii_PredicateState = predicate;
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}
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/* Skip this index-update if the predicate isn't satisfied */
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if (!ExecQual(predicate, econtext, false))
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continue;
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}
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/*
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* FormIndexDatum fills in its values and isnull parameters with the
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* appropriate values for the column(s) of the index.
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*/
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FormIndexDatum(indexInfo,
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slot,
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estate,
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values,
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isnull);
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/*
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* The index AM does the actual insertion, plus uniqueness checking.
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*
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* For an immediate-mode unique index, we just tell the index AM to
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* throw error if not unique.
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*
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* For a deferrable unique index, we tell the index AM to just detect
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* possible non-uniqueness, and we add the index OID to the result
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* list if further checking is needed.
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*/
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if (!indexRelation->rd_index->indisunique)
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checkUnique = UNIQUE_CHECK_NO;
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else if (indexRelation->rd_index->indimmediate)
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checkUnique = UNIQUE_CHECK_YES;
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else
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checkUnique = UNIQUE_CHECK_PARTIAL;
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satisfiesConstraint =
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index_insert(indexRelation, /* index relation */
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values, /* array of index Datums */
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isnull, /* null flags */
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tupleid, /* tid of heap tuple */
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heapRelation, /* heap relation */
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checkUnique); /* type of uniqueness check to do */
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/*
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* If the index has an associated exclusion constraint, check that.
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* This is simpler than the process for uniqueness checks since we
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* always insert first and then check. If the constraint is deferred,
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* we check now anyway, but don't throw error on violation; instead
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* we'll queue a recheck event.
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*
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* An index for an exclusion constraint can't also be UNIQUE (not an
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* essential property, we just don't allow it in the grammar), so no
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* need to preserve the prior state of satisfiesConstraint.
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*/
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if (indexInfo->ii_ExclusionOps != NULL)
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{
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bool errorOK = !indexRelation->rd_index->indimmediate;
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satisfiesConstraint =
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check_exclusion_constraint(heapRelation,
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indexRelation, indexInfo,
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tupleid, values, isnull,
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estate, false, errorOK);
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}
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if ((checkUnique == UNIQUE_CHECK_PARTIAL ||
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indexInfo->ii_ExclusionOps != NULL) &&
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!satisfiesConstraint)
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{
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/*
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* The tuple potentially violates the uniqueness or exclusion
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* constraint, so make a note of the index so that we can re-check
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* it later.
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*/
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result = lappend_oid(result, RelationGetRelid(indexRelation));
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}
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}
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return result;
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}
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/*
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* Check for violation of an exclusion constraint
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*
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* heap: the table containing the new tuple
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* index: the index supporting the exclusion constraint
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* indexInfo: info about the index, including the exclusion properties
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* tupleid: heap TID of the new tuple we have just inserted
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* values, isnull: the *index* column values computed for the new tuple
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* estate: an EState we can do evaluation in
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* newIndex: if true, we are trying to build a new index (this affects
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* only the wording of error messages)
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* errorOK: if true, don't throw error for violation
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*
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* Returns true if OK, false if actual or potential violation
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*
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* When errorOK is true, we report violation without waiting to see if any
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* concurrent transaction has committed or not; so the violation is only
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* potential, and the caller must recheck sometime later. This behavior
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* is convenient for deferred exclusion checks; we need not bother queuing
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* a deferred event if there is definitely no conflict at insertion time.
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*
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* When errorOK is false, we'll throw error on violation, so a false result
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* is impossible.
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*/
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bool
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check_exclusion_constraint(Relation heap, Relation index, IndexInfo *indexInfo,
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ItemPointer tupleid, Datum *values, bool *isnull,
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EState *estate, bool newIndex, bool errorOK)
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{
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Oid *constr_procs = indexInfo->ii_ExclusionProcs;
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uint16 *constr_strats = indexInfo->ii_ExclusionStrats;
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Oid *index_collations = index->rd_indcollation;
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int index_natts = index->rd_index->indnatts;
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IndexScanDesc index_scan;
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HeapTuple tup;
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ScanKeyData scankeys[INDEX_MAX_KEYS];
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SnapshotData DirtySnapshot;
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int i;
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bool conflict;
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bool found_self;
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ExprContext *econtext;
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TupleTableSlot *existing_slot;
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TupleTableSlot *save_scantuple;
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/*
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* If any of the input values are NULL, the constraint check is assumed to
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* pass (i.e., we assume the operators are strict).
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*/
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for (i = 0; i < index_natts; i++)
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{
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if (isnull[i])
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return true;
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}
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/*
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* Search the tuples that are in the index for any violations, including
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* tuples that aren't visible yet.
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*/
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InitDirtySnapshot(DirtySnapshot);
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for (i = 0; i < index_natts; i++)
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{
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ScanKeyEntryInitialize(&scankeys[i],
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0,
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i + 1,
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constr_strats[i],
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InvalidOid,
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index_collations[i],
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constr_procs[i],
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values[i]);
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}
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/*
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* Need a TupleTableSlot to put existing tuples in.
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*
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* To use FormIndexDatum, we have to make the econtext's scantuple point
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* to this slot. Be sure to save and restore caller's value for
|
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* scantuple.
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*/
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existing_slot = MakeSingleTupleTableSlot(RelationGetDescr(heap));
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econtext = GetPerTupleExprContext(estate);
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save_scantuple = econtext->ecxt_scantuple;
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econtext->ecxt_scantuple = existing_slot;
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/*
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* May have to restart scan from this point if a potential conflict is
|
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* found.
|
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*/
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retry:
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conflict = false;
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found_self = false;
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index_scan = index_beginscan(heap, index, &DirtySnapshot, index_natts, 0);
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index_rescan(index_scan, scankeys, index_natts, NULL, 0);
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|
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while ((tup = index_getnext(index_scan,
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ForwardScanDirection)) != NULL)
|
||||
{
|
||||
TransactionId xwait;
|
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ItemPointerData ctid_wait;
|
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Datum existing_values[INDEX_MAX_KEYS];
|
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bool existing_isnull[INDEX_MAX_KEYS];
|
||||
char *error_new;
|
||||
char *error_existing;
|
||||
|
||||
/*
|
||||
* Ignore the entry for the tuple we're trying to check.
|
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*/
|
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if (ItemPointerEquals(tupleid, &tup->t_self))
|
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{
|
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if (found_self) /* should not happen */
|
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elog(ERROR, "found self tuple multiple times in index \"%s\"",
|
||||
RelationGetRelationName(index));
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found_self = true;
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continue;
|
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}
|
||||
|
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/*
|
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* Extract the index column values and isnull flags from the existing
|
||||
* tuple.
|
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*/
|
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ExecStoreTuple(tup, existing_slot, InvalidBuffer, false);
|
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FormIndexDatum(indexInfo, existing_slot, estate,
|
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existing_values, existing_isnull);
|
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|
||||
/* If lossy indexscan, must recheck the condition */
|
||||
if (index_scan->xs_recheck)
|
||||
{
|
||||
if (!index_recheck_constraint(index,
|
||||
constr_procs,
|
||||
existing_values,
|
||||
existing_isnull,
|
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values))
|
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continue; /* tuple doesn't actually match, so no
|
||||
* conflict */
|
||||
}
|
||||
|
||||
/*
|
||||
* At this point we have either a conflict or a potential conflict. If
|
||||
* we're not supposed to raise error, just return the fact of the
|
||||
* potential conflict without waiting to see if it's real.
|
||||
*/
|
||||
if (errorOK)
|
||||
{
|
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conflict = true;
|
||||
break;
|
||||
}
|
||||
|
||||
/*
|
||||
* If an in-progress transaction is affecting the visibility of this
|
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* tuple, we need to wait for it to complete and then recheck. For
|
||||
* simplicity we do rechecking by just restarting the whole scan ---
|
||||
* this case probably doesn't happen often enough to be worth trying
|
||||
* harder, and anyway we don't want to hold any index internal locks
|
||||
* while waiting.
|
||||
*/
|
||||
xwait = TransactionIdIsValid(DirtySnapshot.xmin) ?
|
||||
DirtySnapshot.xmin : DirtySnapshot.xmax;
|
||||
|
||||
if (TransactionIdIsValid(xwait))
|
||||
{
|
||||
ctid_wait = tup->t_data->t_ctid;
|
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index_endscan(index_scan);
|
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XactLockTableWait(xwait, heap, &ctid_wait,
|
||||
XLTW_RecheckExclusionConstr);
|
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goto retry;
|
||||
}
|
||||
|
||||
/*
|
||||
* We have a definite conflict. Report it.
|
||||
*/
|
||||
error_new = BuildIndexValueDescription(index, values, isnull);
|
||||
error_existing = BuildIndexValueDescription(index, existing_values,
|
||||
existing_isnull);
|
||||
if (newIndex)
|
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ereport(ERROR,
|
||||
(errcode(ERRCODE_EXCLUSION_VIOLATION),
|
||||
errmsg("could not create exclusion constraint \"%s\"",
|
||||
RelationGetRelationName(index)),
|
||||
error_new && error_existing ?
|
||||
errdetail("Key %s conflicts with key %s.",
|
||||
error_new, error_existing) :
|
||||
errdetail("Key conflicts exist."),
|
||||
errtableconstraint(heap,
|
||||
RelationGetRelationName(index))));
|
||||
else
|
||||
ereport(ERROR,
|
||||
(errcode(ERRCODE_EXCLUSION_VIOLATION),
|
||||
errmsg("conflicting key value violates exclusion constraint \"%s\"",
|
||||
RelationGetRelationName(index)),
|
||||
error_new && error_existing ?
|
||||
errdetail("Key %s conflicts with existing key %s.",
|
||||
error_new, error_existing) :
|
||||
errdetail("Key conflicts with existing key."),
|
||||
errtableconstraint(heap,
|
||||
RelationGetRelationName(index))));
|
||||
}
|
||||
|
||||
index_endscan(index_scan);
|
||||
|
||||
/*
|
||||
* Ordinarily, at this point the search should have found the originally
|
||||
* inserted tuple, unless we exited the loop early because of conflict.
|
||||
* However, it is possible to define exclusion constraints for which that
|
||||
* wouldn't be true --- for instance, if the operator is <>. So we no
|
||||
* longer complain if found_self is still false.
|
||||
*/
|
||||
|
||||
econtext->ecxt_scantuple = save_scantuple;
|
||||
|
||||
ExecDropSingleTupleTableSlot(existing_slot);
|
||||
|
||||
return !conflict;
|
||||
}
|
||||
|
||||
/*
|
||||
* Check existing tuple's index values to see if it really matches the
|
||||
* exclusion condition against the new_values. Returns true if conflict.
|
||||
*/
|
||||
static bool
|
||||
index_recheck_constraint(Relation index, Oid *constr_procs,
|
||||
Datum *existing_values, bool *existing_isnull,
|
||||
Datum *new_values)
|
||||
{
|
||||
int index_natts = index->rd_index->indnatts;
|
||||
int i;
|
||||
|
||||
for (i = 0; i < index_natts; i++)
|
||||
{
|
||||
/* Assume the exclusion operators are strict */
|
||||
if (existing_isnull[i])
|
||||
return false;
|
||||
|
||||
if (!DatumGetBool(OidFunctionCall2Coll(constr_procs[i],
|
||||
index->rd_indcollation[i],
|
||||
existing_values[i],
|
||||
new_values[i])))
|
||||
return false;
|
||||
}
|
||||
|
||||
return true;
|
||||
}
|
||||
@ -28,10 +28,6 @@
|
||||
* ExecOpenScanRelation Common code for scan node init routines.
|
||||
* ExecCloseScanRelation
|
||||
*
|
||||
* ExecOpenIndices \
|
||||
* ExecCloseIndices | referenced by InitPlan, EndPlan,
|
||||
* ExecInsertIndexTuples / ExecInsert, ExecUpdate
|
||||
*
|
||||
* RegisterExprContextCallback Register function shutdown callback
|
||||
* UnregisterExprContextCallback Deregister function shutdown callback
|
||||
*
|
||||
@ -44,19 +40,14 @@
|
||||
|
||||
#include "access/relscan.h"
|
||||
#include "access/transam.h"
|
||||
#include "catalog/index.h"
|
||||
#include "executor/execdebug.h"
|
||||
#include "executor/executor.h"
|
||||
#include "nodes/nodeFuncs.h"
|
||||
#include "parser/parsetree.h"
|
||||
#include "storage/lmgr.h"
|
||||
#include "utils/memutils.h"
|
||||
#include "utils/tqual.h"
|
||||
#include "utils/rel.h"
|
||||
|
||||
|
||||
static bool get_last_attnums(Node *node, ProjectionInfo *projInfo);
|
||||
static bool index_recheck_constraint(Relation index, Oid *constr_procs,
|
||||
Datum *existing_values, bool *existing_isnull,
|
||||
Datum *new_values);
|
||||
static void ShutdownExprContext(ExprContext *econtext, bool isCommit);
|
||||
|
||||
|
||||
@ -870,527 +861,6 @@ ExecCloseScanRelation(Relation scanrel)
|
||||
heap_close(scanrel, NoLock);
|
||||
}
|
||||
|
||||
|
||||
/* ----------------------------------------------------------------
|
||||
* ExecInsertIndexTuples support
|
||||
* ----------------------------------------------------------------
|
||||
*/
|
||||
|
||||
/* ----------------------------------------------------------------
|
||||
* ExecOpenIndices
|
||||
*
|
||||
* Find the indices associated with a result relation, open them,
|
||||
* and save information about them in the result ResultRelInfo.
|
||||
*
|
||||
* At entry, caller has already opened and locked
|
||||
* resultRelInfo->ri_RelationDesc.
|
||||
* ----------------------------------------------------------------
|
||||
*/
|
||||
void
|
||||
ExecOpenIndices(ResultRelInfo *resultRelInfo)
|
||||
{
|
||||
Relation resultRelation = resultRelInfo->ri_RelationDesc;
|
||||
List *indexoidlist;
|
||||
ListCell *l;
|
||||
int len,
|
||||
i;
|
||||
RelationPtr relationDescs;
|
||||
IndexInfo **indexInfoArray;
|
||||
|
||||
resultRelInfo->ri_NumIndices = 0;
|
||||
|
||||
/* fast path if no indexes */
|
||||
if (!RelationGetForm(resultRelation)->relhasindex)
|
||||
return;
|
||||
|
||||
/*
|
||||
* Get cached list of index OIDs
|
||||
*/
|
||||
indexoidlist = RelationGetIndexList(resultRelation);
|
||||
len = list_length(indexoidlist);
|
||||
if (len == 0)
|
||||
return;
|
||||
|
||||
/*
|
||||
* allocate space for result arrays
|
||||
*/
|
||||
relationDescs = (RelationPtr) palloc(len * sizeof(Relation));
|
||||
indexInfoArray = (IndexInfo **) palloc(len * sizeof(IndexInfo *));
|
||||
|
||||
resultRelInfo->ri_NumIndices = len;
|
||||
resultRelInfo->ri_IndexRelationDescs = relationDescs;
|
||||
resultRelInfo->ri_IndexRelationInfo = indexInfoArray;
|
||||
|
||||
/*
|
||||
* For each index, open the index relation and save pg_index info. We
|
||||
* acquire RowExclusiveLock, signifying we will update the index.
|
||||
*
|
||||
* Note: we do this even if the index is not IndexIsReady; it's not worth
|
||||
* the trouble to optimize for the case where it isn't.
|
||||
*/
|
||||
i = 0;
|
||||
foreach(l, indexoidlist)
|
||||
{
|
||||
Oid indexOid = lfirst_oid(l);
|
||||
Relation indexDesc;
|
||||
IndexInfo *ii;
|
||||
|
||||
indexDesc = index_open(indexOid, RowExclusiveLock);
|
||||
|
||||
/* extract index key information from the index's pg_index info */
|
||||
ii = BuildIndexInfo(indexDesc);
|
||||
|
||||
relationDescs[i] = indexDesc;
|
||||
indexInfoArray[i] = ii;
|
||||
i++;
|
||||
}
|
||||
|
||||
list_free(indexoidlist);
|
||||
}
|
||||
|
||||
/* ----------------------------------------------------------------
|
||||
* ExecCloseIndices
|
||||
*
|
||||
* Close the index relations stored in resultRelInfo
|
||||
* ----------------------------------------------------------------
|
||||
*/
|
||||
void
|
||||
ExecCloseIndices(ResultRelInfo *resultRelInfo)
|
||||
{
|
||||
int i;
|
||||
int numIndices;
|
||||
RelationPtr indexDescs;
|
||||
|
||||
numIndices = resultRelInfo->ri_NumIndices;
|
||||
indexDescs = resultRelInfo->ri_IndexRelationDescs;
|
||||
|
||||
for (i = 0; i < numIndices; i++)
|
||||
{
|
||||
if (indexDescs[i] == NULL)
|
||||
continue; /* shouldn't happen? */
|
||||
|
||||
/* Drop lock acquired by ExecOpenIndices */
|
||||
index_close(indexDescs[i], RowExclusiveLock);
|
||||
}
|
||||
|
||||
/*
|
||||
* XXX should free indexInfo array here too? Currently we assume that
|
||||
* such stuff will be cleaned up automatically in FreeExecutorState.
|
||||
*/
|
||||
}
|
||||
|
||||
/* ----------------------------------------------------------------
|
||||
* ExecInsertIndexTuples
|
||||
*
|
||||
* This routine takes care of inserting index tuples
|
||||
* into all the relations indexing the result relation
|
||||
* when a heap tuple is inserted into the result relation.
|
||||
* Much of this code should be moved into the genam
|
||||
* stuff as it only exists here because the genam stuff
|
||||
* doesn't provide the functionality needed by the
|
||||
* executor.. -cim 9/27/89
|
||||
*
|
||||
* This returns a list of index OIDs for any unique or exclusion
|
||||
* constraints that are deferred and that had
|
||||
* potential (unconfirmed) conflicts.
|
||||
*
|
||||
* CAUTION: this must not be called for a HOT update.
|
||||
* We can't defend against that here for lack of info.
|
||||
* Should we change the API to make it safer?
|
||||
* ----------------------------------------------------------------
|
||||
*/
|
||||
List *
|
||||
ExecInsertIndexTuples(TupleTableSlot *slot,
|
||||
ItemPointer tupleid,
|
||||
EState *estate)
|
||||
{
|
||||
List *result = NIL;
|
||||
ResultRelInfo *resultRelInfo;
|
||||
int i;
|
||||
int numIndices;
|
||||
RelationPtr relationDescs;
|
||||
Relation heapRelation;
|
||||
IndexInfo **indexInfoArray;
|
||||
ExprContext *econtext;
|
||||
Datum values[INDEX_MAX_KEYS];
|
||||
bool isnull[INDEX_MAX_KEYS];
|
||||
|
||||
/*
|
||||
* Get information from the result relation info structure.
|
||||
*/
|
||||
resultRelInfo = estate->es_result_relation_info;
|
||||
numIndices = resultRelInfo->ri_NumIndices;
|
||||
relationDescs = resultRelInfo->ri_IndexRelationDescs;
|
||||
indexInfoArray = resultRelInfo->ri_IndexRelationInfo;
|
||||
heapRelation = resultRelInfo->ri_RelationDesc;
|
||||
|
||||
/*
|
||||
* We will use the EState's per-tuple context for evaluating predicates
|
||||
* and index expressions (creating it if it's not already there).
|
||||
*/
|
||||
econtext = GetPerTupleExprContext(estate);
|
||||
|
||||
/* Arrange for econtext's scan tuple to be the tuple under test */
|
||||
econtext->ecxt_scantuple = slot;
|
||||
|
||||
/*
|
||||
* for each index, form and insert the index tuple
|
||||
*/
|
||||
for (i = 0; i < numIndices; i++)
|
||||
{
|
||||
Relation indexRelation = relationDescs[i];
|
||||
IndexInfo *indexInfo;
|
||||
IndexUniqueCheck checkUnique;
|
||||
bool satisfiesConstraint;
|
||||
|
||||
if (indexRelation == NULL)
|
||||
continue;
|
||||
|
||||
indexInfo = indexInfoArray[i];
|
||||
|
||||
/* If the index is marked as read-only, ignore it */
|
||||
if (!indexInfo->ii_ReadyForInserts)
|
||||
continue;
|
||||
|
||||
/* Check for partial index */
|
||||
if (indexInfo->ii_Predicate != NIL)
|
||||
{
|
||||
List *predicate;
|
||||
|
||||
/*
|
||||
* If predicate state not set up yet, create it (in the estate's
|
||||
* per-query context)
|
||||
*/
|
||||
predicate = indexInfo->ii_PredicateState;
|
||||
if (predicate == NIL)
|
||||
{
|
||||
predicate = (List *)
|
||||
ExecPrepareExpr((Expr *) indexInfo->ii_Predicate,
|
||||
estate);
|
||||
indexInfo->ii_PredicateState = predicate;
|
||||
}
|
||||
|
||||
/* Skip this index-update if the predicate isn't satisfied */
|
||||
if (!ExecQual(predicate, econtext, false))
|
||||
continue;
|
||||
}
|
||||
|
||||
/*
|
||||
* FormIndexDatum fills in its values and isnull parameters with the
|
||||
* appropriate values for the column(s) of the index.
|
||||
*/
|
||||
FormIndexDatum(indexInfo,
|
||||
slot,
|
||||
estate,
|
||||
values,
|
||||
isnull);
|
||||
|
||||
/*
|
||||
* The index AM does the actual insertion, plus uniqueness checking.
|
||||
*
|
||||
* For an immediate-mode unique index, we just tell the index AM to
|
||||
* throw error if not unique.
|
||||
*
|
||||
* For a deferrable unique index, we tell the index AM to just detect
|
||||
* possible non-uniqueness, and we add the index OID to the result
|
||||
* list if further checking is needed.
|
||||
*/
|
||||
if (!indexRelation->rd_index->indisunique)
|
||||
checkUnique = UNIQUE_CHECK_NO;
|
||||
else if (indexRelation->rd_index->indimmediate)
|
||||
checkUnique = UNIQUE_CHECK_YES;
|
||||
else
|
||||
checkUnique = UNIQUE_CHECK_PARTIAL;
|
||||
|
||||
satisfiesConstraint =
|
||||
index_insert(indexRelation, /* index relation */
|
||||
values, /* array of index Datums */
|
||||
isnull, /* null flags */
|
||||
tupleid, /* tid of heap tuple */
|
||||
heapRelation, /* heap relation */
|
||||
checkUnique); /* type of uniqueness check to do */
|
||||
|
||||
/*
|
||||
* If the index has an associated exclusion constraint, check that.
|
||||
* This is simpler than the process for uniqueness checks since we
|
||||
* always insert first and then check. If the constraint is deferred,
|
||||
* we check now anyway, but don't throw error on violation; instead
|
||||
* we'll queue a recheck event.
|
||||
*
|
||||
* An index for an exclusion constraint can't also be UNIQUE (not an
|
||||
* essential property, we just don't allow it in the grammar), so no
|
||||
* need to preserve the prior state of satisfiesConstraint.
|
||||
*/
|
||||
if (indexInfo->ii_ExclusionOps != NULL)
|
||||
{
|
||||
bool errorOK = !indexRelation->rd_index->indimmediate;
|
||||
|
||||
satisfiesConstraint =
|
||||
check_exclusion_constraint(heapRelation,
|
||||
indexRelation, indexInfo,
|
||||
tupleid, values, isnull,
|
||||
estate, false, errorOK);
|
||||
}
|
||||
|
||||
if ((checkUnique == UNIQUE_CHECK_PARTIAL ||
|
||||
indexInfo->ii_ExclusionOps != NULL) &&
|
||||
!satisfiesConstraint)
|
||||
{
|
||||
/*
|
||||
* The tuple potentially violates the uniqueness or exclusion
|
||||
* constraint, so make a note of the index so that we can re-check
|
||||
* it later.
|
||||
*/
|
||||
result = lappend_oid(result, RelationGetRelid(indexRelation));
|
||||
}
|
||||
}
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
/*
|
||||
* Check for violation of an exclusion constraint
|
||||
*
|
||||
* heap: the table containing the new tuple
|
||||
* index: the index supporting the exclusion constraint
|
||||
* indexInfo: info about the index, including the exclusion properties
|
||||
* tupleid: heap TID of the new tuple we have just inserted
|
||||
* values, isnull: the *index* column values computed for the new tuple
|
||||
* estate: an EState we can do evaluation in
|
||||
* newIndex: if true, we are trying to build a new index (this affects
|
||||
* only the wording of error messages)
|
||||
* errorOK: if true, don't throw error for violation
|
||||
*
|
||||
* Returns true if OK, false if actual or potential violation
|
||||
*
|
||||
* When errorOK is true, we report violation without waiting to see if any
|
||||
* concurrent transaction has committed or not; so the violation is only
|
||||
* potential, and the caller must recheck sometime later. This behavior
|
||||
* is convenient for deferred exclusion checks; we need not bother queuing
|
||||
* a deferred event if there is definitely no conflict at insertion time.
|
||||
*
|
||||
* When errorOK is false, we'll throw error on violation, so a false result
|
||||
* is impossible.
|
||||
*/
|
||||
bool
|
||||
check_exclusion_constraint(Relation heap, Relation index, IndexInfo *indexInfo,
|
||||
ItemPointer tupleid, Datum *values, bool *isnull,
|
||||
EState *estate, bool newIndex, bool errorOK)
|
||||
{
|
||||
Oid *constr_procs = indexInfo->ii_ExclusionProcs;
|
||||
uint16 *constr_strats = indexInfo->ii_ExclusionStrats;
|
||||
Oid *index_collations = index->rd_indcollation;
|
||||
int index_natts = index->rd_index->indnatts;
|
||||
IndexScanDesc index_scan;
|
||||
HeapTuple tup;
|
||||
ScanKeyData scankeys[INDEX_MAX_KEYS];
|
||||
SnapshotData DirtySnapshot;
|
||||
int i;
|
||||
bool conflict;
|
||||
bool found_self;
|
||||
ExprContext *econtext;
|
||||
TupleTableSlot *existing_slot;
|
||||
TupleTableSlot *save_scantuple;
|
||||
|
||||
/*
|
||||
* If any of the input values are NULL, the constraint check is assumed to
|
||||
* pass (i.e., we assume the operators are strict).
|
||||
*/
|
||||
for (i = 0; i < index_natts; i++)
|
||||
{
|
||||
if (isnull[i])
|
||||
return true;
|
||||
}
|
||||
|
||||
/*
|
||||
* Search the tuples that are in the index for any violations, including
|
||||
* tuples that aren't visible yet.
|
||||
*/
|
||||
InitDirtySnapshot(DirtySnapshot);
|
||||
|
||||
for (i = 0; i < index_natts; i++)
|
||||
{
|
||||
ScanKeyEntryInitialize(&scankeys[i],
|
||||
0,
|
||||
i + 1,
|
||||
constr_strats[i],
|
||||
InvalidOid,
|
||||
index_collations[i],
|
||||
constr_procs[i],
|
||||
values[i]);
|
||||
}
|
||||
|
||||
/*
|
||||
* Need a TupleTableSlot to put existing tuples in.
|
||||
*
|
||||
* To use FormIndexDatum, we have to make the econtext's scantuple point
|
||||
* to this slot. Be sure to save and restore caller's value for
|
||||
* scantuple.
|
||||
*/
|
||||
existing_slot = MakeSingleTupleTableSlot(RelationGetDescr(heap));
|
||||
|
||||
econtext = GetPerTupleExprContext(estate);
|
||||
save_scantuple = econtext->ecxt_scantuple;
|
||||
econtext->ecxt_scantuple = existing_slot;
|
||||
|
||||
/*
|
||||
* May have to restart scan from this point if a potential conflict is
|
||||
* found.
|
||||
*/
|
||||
retry:
|
||||
conflict = false;
|
||||
found_self = false;
|
||||
index_scan = index_beginscan(heap, index, &DirtySnapshot, index_natts, 0);
|
||||
index_rescan(index_scan, scankeys, index_natts, NULL, 0);
|
||||
|
||||
while ((tup = index_getnext(index_scan,
|
||||
ForwardScanDirection)) != NULL)
|
||||
{
|
||||
TransactionId xwait;
|
||||
ItemPointerData ctid_wait;
|
||||
Datum existing_values[INDEX_MAX_KEYS];
|
||||
bool existing_isnull[INDEX_MAX_KEYS];
|
||||
char *error_new;
|
||||
char *error_existing;
|
||||
|
||||
/*
|
||||
* Ignore the entry for the tuple we're trying to check.
|
||||
*/
|
||||
if (ItemPointerEquals(tupleid, &tup->t_self))
|
||||
{
|
||||
if (found_self) /* should not happen */
|
||||
elog(ERROR, "found self tuple multiple times in index \"%s\"",
|
||||
RelationGetRelationName(index));
|
||||
found_self = true;
|
||||
continue;
|
||||
}
|
||||
|
||||
/*
|
||||
* Extract the index column values and isnull flags from the existing
|
||||
* tuple.
|
||||
*/
|
||||
ExecStoreTuple(tup, existing_slot, InvalidBuffer, false);
|
||||
FormIndexDatum(indexInfo, existing_slot, estate,
|
||||
existing_values, existing_isnull);
|
||||
|
||||
/* If lossy indexscan, must recheck the condition */
|
||||
if (index_scan->xs_recheck)
|
||||
{
|
||||
if (!index_recheck_constraint(index,
|
||||
constr_procs,
|
||||
existing_values,
|
||||
existing_isnull,
|
||||
values))
|
||||
continue; /* tuple doesn't actually match, so no
|
||||
* conflict */
|
||||
}
|
||||
|
||||
/*
|
||||
* At this point we have either a conflict or a potential conflict. If
|
||||
* we're not supposed to raise error, just return the fact of the
|
||||
* potential conflict without waiting to see if it's real.
|
||||
*/
|
||||
if (errorOK)
|
||||
{
|
||||
conflict = true;
|
||||
break;
|
||||
}
|
||||
|
||||
/*
|
||||
* If an in-progress transaction is affecting the visibility of this
|
||||
* tuple, we need to wait for it to complete and then recheck. For
|
||||
* simplicity we do rechecking by just restarting the whole scan ---
|
||||
* this case probably doesn't happen often enough to be worth trying
|
||||
* harder, and anyway we don't want to hold any index internal locks
|
||||
* while waiting.
|
||||
*/
|
||||
xwait = TransactionIdIsValid(DirtySnapshot.xmin) ?
|
||||
DirtySnapshot.xmin : DirtySnapshot.xmax;
|
||||
|
||||
if (TransactionIdIsValid(xwait))
|
||||
{
|
||||
ctid_wait = tup->t_data->t_ctid;
|
||||
index_endscan(index_scan);
|
||||
XactLockTableWait(xwait, heap, &ctid_wait,
|
||||
XLTW_RecheckExclusionConstr);
|
||||
goto retry;
|
||||
}
|
||||
|
||||
/*
|
||||
* We have a definite conflict. Report it.
|
||||
*/
|
||||
error_new = BuildIndexValueDescription(index, values, isnull);
|
||||
error_existing = BuildIndexValueDescription(index, existing_values,
|
||||
existing_isnull);
|
||||
if (newIndex)
|
||||
ereport(ERROR,
|
||||
(errcode(ERRCODE_EXCLUSION_VIOLATION),
|
||||
errmsg("could not create exclusion constraint \"%s\"",
|
||||
RelationGetRelationName(index)),
|
||||
error_new && error_existing ?
|
||||
errdetail("Key %s conflicts with key %s.",
|
||||
error_new, error_existing) :
|
||||
errdetail("Key conflicts exist."),
|
||||
errtableconstraint(heap,
|
||||
RelationGetRelationName(index))));
|
||||
else
|
||||
ereport(ERROR,
|
||||
(errcode(ERRCODE_EXCLUSION_VIOLATION),
|
||||
errmsg("conflicting key value violates exclusion constraint \"%s\"",
|
||||
RelationGetRelationName(index)),
|
||||
error_new && error_existing ?
|
||||
errdetail("Key %s conflicts with existing key %s.",
|
||||
error_new, error_existing) :
|
||||
errdetail("Key conflicts with existing key."),
|
||||
errtableconstraint(heap,
|
||||
RelationGetRelationName(index))));
|
||||
}
|
||||
|
||||
index_endscan(index_scan);
|
||||
|
||||
/*
|
||||
* Ordinarily, at this point the search should have found the originally
|
||||
* inserted tuple, unless we exited the loop early because of conflict.
|
||||
* However, it is possible to define exclusion constraints for which that
|
||||
* wouldn't be true --- for instance, if the operator is <>. So we no
|
||||
* longer complain if found_self is still false.
|
||||
*/
|
||||
|
||||
econtext->ecxt_scantuple = save_scantuple;
|
||||
|
||||
ExecDropSingleTupleTableSlot(existing_slot);
|
||||
|
||||
return !conflict;
|
||||
}
|
||||
|
||||
/*
|
||||
* Check existing tuple's index values to see if it really matches the
|
||||
* exclusion condition against the new_values. Returns true if conflict.
|
||||
*/
|
||||
static bool
|
||||
index_recheck_constraint(Relation index, Oid *constr_procs,
|
||||
Datum *existing_values, bool *existing_isnull,
|
||||
Datum *new_values)
|
||||
{
|
||||
int index_natts = index->rd_index->indnatts;
|
||||
int i;
|
||||
|
||||
for (i = 0; i < index_natts; i++)
|
||||
{
|
||||
/* Assume the exclusion operators are strict */
|
||||
if (existing_isnull[i])
|
||||
return false;
|
||||
|
||||
if (!DatumGetBool(OidFunctionCall2Coll(constr_procs[i],
|
||||
index->rd_indcollation[i],
|
||||
existing_values[i],
|
||||
new_values[i])))
|
||||
return false;
|
||||
}
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
/*
|
||||
* UpdateChangedParamSet
|
||||
* Add changed parameters to a plan node's chgParam set
|
||||
|
||||
@ -351,6 +351,16 @@ extern bool ExecRelationIsTargetRelation(EState *estate, Index scanrelid);
|
||||
extern Relation ExecOpenScanRelation(EState *estate, Index scanrelid, int eflags);
|
||||
extern void ExecCloseScanRelation(Relation scanrel);
|
||||
|
||||
extern void RegisterExprContextCallback(ExprContext *econtext,
|
||||
ExprContextCallbackFunction function,
|
||||
Datum arg);
|
||||
extern void UnregisterExprContextCallback(ExprContext *econtext,
|
||||
ExprContextCallbackFunction function,
|
||||
Datum arg);
|
||||
|
||||
/*
|
||||
* prototypes from functions in execIndexing.c
|
||||
*/
|
||||
extern void ExecOpenIndices(ResultRelInfo *resultRelInfo);
|
||||
extern void ExecCloseIndices(ResultRelInfo *resultRelInfo);
|
||||
extern List *ExecInsertIndexTuples(TupleTableSlot *slot, ItemPointer tupleid,
|
||||
@ -362,11 +372,5 @@ extern bool check_exclusion_constraint(Relation heap, Relation index,
|
||||
EState *estate,
|
||||
bool newIndex, bool errorOK);
|
||||
|
||||
extern void RegisterExprContextCallback(ExprContext *econtext,
|
||||
ExprContextCallbackFunction function,
|
||||
Datum arg);
|
||||
extern void UnregisterExprContextCallback(ExprContext *econtext,
|
||||
ExprContextCallbackFunction function,
|
||||
Datum arg);
|
||||
|
||||
#endif /* EXECUTOR_H */
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user