diff options
Diffstat (limited to 'src/backend/executor')
| -rw-r--r-- | src/backend/executor/execUtils.c | 42 | ||||
| -rw-r--r-- | src/backend/executor/nodeBitmapIndexscan.c | 21 | ||||
| -rw-r--r-- | src/backend/executor/nodeIndexscan.c | 21 |
3 files changed, 22 insertions, 62 deletions
diff --git a/src/backend/executor/execUtils.c b/src/backend/executor/execUtils.c index 11f2ae20f5e..c879de3bbc1 100644 --- a/src/backend/executor/execUtils.c +++ b/src/backend/executor/execUtils.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/executor/execUtils.c,v 1.137 2006/07/14 14:52:19 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/executor/execUtils.c,v 1.138 2006/07/31 20:09:04 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -795,12 +795,6 @@ ExecCloseScanRelation(Relation scanrel) * * At entry, caller has already opened and locked * resultRelInfo->ri_RelationDesc. - * - * This used to be horribly ugly code, and slow too because it - * did a sequential scan of pg_index. Now we rely on the relcache - * to cache a list of the OIDs of the indices associated with any - * specific relation, and we use the pg_index syscache to get the - * entries we need from pg_index. * ---------------------------------------------------------------- */ void @@ -840,6 +834,7 @@ ExecOpenIndices(ResultRelInfo *resultRelInfo) /* * For each index, open the index relation and save pg_index info. + * We acquire RowExclusiveLock, signifying we will update the index. */ i = 0; foreach(l, indexoidlist) @@ -848,31 +843,7 @@ ExecOpenIndices(ResultRelInfo *resultRelInfo) Relation indexDesc; IndexInfo *ii; - /* - * Open and lock the index relation - * - * If the index AM supports concurrent updates, obtain - * RowExclusiveLock to signify that we are updating the index. This - * locks out only operations that need exclusive access, such as - * relocating the index to a new tablespace. - * - * If the index AM is not safe for concurrent updates, obtain an - * exclusive lock on the index to lock out other updaters as well as - * readers (index_beginscan places AccessShareLock on the index). - * - * If there are multiple not-concurrent-safe indexes, all backends - * must lock the indexes in the same order or we will get deadlocks - * here. This is guaranteed by RelationGetIndexList(), which promises - * to return the index list in OID order. - * - * The locks will be released in ExecCloseIndices. - */ - indexDesc = index_open(indexOid); - - if (indexDesc->rd_am->amconcurrent) - LockRelation(indexDesc, RowExclusiveLock); - else - LockRelation(indexDesc, AccessExclusiveLock); + indexDesc = index_open(indexOid, RowExclusiveLock); /* extract index key information from the index's pg_index info */ ii = BuildIndexInfo(indexDesc); @@ -907,12 +878,7 @@ ExecCloseIndices(ResultRelInfo *resultRelInfo) continue; /* shouldn't happen? */ /* Drop lock acquired by ExecOpenIndices */ - if (indexDescs[i]->rd_am->amconcurrent) - UnlockRelation(indexDescs[i], RowExclusiveLock); - else - UnlockRelation(indexDescs[i], AccessExclusiveLock); - - index_close(indexDescs[i]); + index_close(indexDescs[i], RowExclusiveLock); } /* diff --git a/src/backend/executor/nodeBitmapIndexscan.c b/src/backend/executor/nodeBitmapIndexscan.c index 7555b5a22ca..6a0303cddd1 100644 --- a/src/backend/executor/nodeBitmapIndexscan.c +++ b/src/backend/executor/nodeBitmapIndexscan.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/executor/nodeBitmapIndexscan.c,v 1.19 2006/05/30 14:01:58 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/executor/nodeBitmapIndexscan.c,v 1.20 2006/07/31 20:09:04 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -201,7 +201,7 @@ ExecEndBitmapIndexScan(BitmapIndexScanState *node) * close the index relation */ index_endscan(indexScanDesc); - index_close(indexRelationDesc); + index_close(indexRelationDesc, NoLock); } /* ---------------------------------------------------------------- @@ -258,8 +258,14 @@ ExecInitBitmapIndexScan(BitmapIndexScan *node, EState *estate, int eflags) /* * Open the index relation. + * + * If the parent table is one of the target relations of the query, then + * InitPlan already opened and write-locked the index, so we can avoid + * taking another lock here. Otherwise we need a normal reader's lock. */ - indexstate->biss_RelationDesc = index_open(node->indexid); + relistarget = ExecRelationIsTargetRelation(estate, node->scan.scanrelid); + indexstate->biss_RelationDesc = index_open(node->indexid, + relistarget ? NoLock : AccessShareLock); /* * Initialize index-specific scan state @@ -303,18 +309,9 @@ ExecInitBitmapIndexScan(BitmapIndexScan *node, EState *estate, int eflags) /* * Initialize scan descriptor. - * - * Note we acquire no locks here; the index machinery does its own locks - * and unlocks. (We rely on having a lock on the parent table to - * ensure the index won't go away!) Furthermore, if the parent table - * is one of the target relations of the query, then InitPlan already - * opened and write-locked the index, so we can tell the index machinery - * not to bother getting an extra lock. */ - relistarget = ExecRelationIsTargetRelation(estate, node->scan.scanrelid); indexstate->biss_ScanDesc = index_beginscan_multi(indexstate->biss_RelationDesc, - !relistarget, estate->es_snapshot, indexstate->biss_NumScanKeys, indexstate->biss_ScanKeys); diff --git a/src/backend/executor/nodeIndexscan.c b/src/backend/executor/nodeIndexscan.c index 02f83667a45..84ee56beb0f 100644 --- a/src/backend/executor/nodeIndexscan.c +++ b/src/backend/executor/nodeIndexscan.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/executor/nodeIndexscan.c,v 1.115 2006/07/14 14:52:19 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/executor/nodeIndexscan.c,v 1.116 2006/07/31 20:09:04 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -415,7 +415,7 @@ ExecEndIndexScan(IndexScanState *node) * close the index relation */ index_endscan(indexScanDesc); - index_close(indexRelationDesc); + index_close(indexRelationDesc, NoLock); /* * close the heap relation. @@ -517,8 +517,14 @@ ExecInitIndexScan(IndexScan *node, EState *estate, int eflags) /* * Open the index relation. + * + * If the parent table is one of the target relations of the query, then + * InitPlan already opened and write-locked the index, so we can avoid + * taking another lock here. Otherwise we need a normal reader's lock. */ - indexstate->iss_RelationDesc = index_open(node->indexid); + relistarget = ExecRelationIsTargetRelation(estate, node->scan.scanrelid); + indexstate->iss_RelationDesc = index_open(node->indexid, + relistarget ? NoLock : AccessShareLock); /* * Initialize index-specific scan state @@ -561,18 +567,9 @@ ExecInitIndexScan(IndexScan *node, EState *estate, int eflags) /* * Initialize scan descriptor. - * - * Note we acquire no locks here; the index machinery does its own locks - * and unlocks. (We rely on having a lock on the parent table to - * ensure the index won't go away!) Furthermore, if the parent table - * is one of the target relations of the query, then InitPlan already - * opened and write-locked the index, so we can tell the index machinery - * not to bother getting an extra lock. */ - relistarget = ExecRelationIsTargetRelation(estate, node->scan.scanrelid); indexstate->iss_ScanDesc = index_beginscan(currentRelation, indexstate->iss_RelationDesc, - !relistarget, estate->es_snapshot, indexstate->iss_NumScanKeys, indexstate->iss_ScanKeys); |