top_builddir = ../../..
include $(top_builddir)/src/Makefile.global
-OBJS = execAmi.o execCurrent.o execGrouping.o execJunk.o execMain.o \
- execProcnode.o execQual.o execScan.o execTuples.o \
+OBJS = execAmi.o execCurrent.o execGrouping.o execIndexing.o execJunk.o \
+ execMain.o execProcnode.o execQual.o execScan.o execTuples.o \
execUtils.o functions.o instrument.o nodeAppend.o nodeAgg.o \
nodeBitmapAnd.o nodeBitmapOr.o \
nodeBitmapHeapscan.o nodeBitmapIndexscan.o nodeCustom.o nodeHash.o \
--- /dev/null
+/*-------------------------------------------------------------------------
+ *
+ * execIndexing.c
+ * executor support for maintaining indexes
+ *
+ * Portions Copyright (c) 1996-2015, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ * src/backend/executor/execIndexing.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "access/relscan.h"
+#include "catalog/index.h"
+#include "executor/executor.h"
+#include "nodes/nodeFuncs.h"
+#include "storage/lmgr.h"
+#include "utils/tqual.h"
+
+static bool index_recheck_constraint(Relation index, Oid *constr_procs,
+ Datum *existing_values, bool *existing_isnull,
+ Datum *new_values);
+
+/* ----------------------------------------------------------------
+ * 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;
+}
* 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
*
#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);
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
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,
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 */
projects / postgresql / commitdiff