From 8205b2d7da0c3ad3cbc5cead336ced677996b37d Mon Sep 17 00:00:00 2001 From: Melanie Plageman Date: Wed, 3 Dec 2025 15:12:18 -0500 Subject: [PATCH v34 12/14] Pass down information on table modification to scan node Pass down information to sequential scan, index [only] scan, and bitmap table scan nodes on whether or not the query modifies the relation being scanned. A later commit will use this information to update the VM during on-access pruning only if the relation is not modified by the query. Author: Melanie Plageman Reviewed-by: Andrey Borodin Reviewed-by: Chao Li Discussion: https://postgr.es/m/4379FDA3-9446-4E2C-9C15-32EFE8D4F31B%40yandex-team.ru --- contrib/pgrowlocks/pgrowlocks.c | 2 +- src/backend/access/brin/brin.c | 3 ++- src/backend/access/gin/gininsert.c | 3 ++- src/backend/access/heap/heapam_handler.c | 7 +++--- src/backend/access/index/genam.c | 4 ++-- src/backend/access/index/indexam.c | 6 +++--- src/backend/access/nbtree/nbtsort.c | 2 +- src/backend/access/table/tableam.c | 7 +++--- src/backend/commands/constraint.c | 2 +- src/backend/commands/copyto.c | 2 +- src/backend/commands/tablecmds.c | 8 +++---- src/backend/commands/typecmds.c | 4 ++-- src/backend/executor/execIndexing.c | 2 +- src/backend/executor/execReplication.c | 8 +++---- src/backend/executor/nodeBitmapHeapscan.c | 9 +++++++- src/backend/executor/nodeIndexonlyscan.c | 9 +++++++- src/backend/executor/nodeIndexscan.c | 18 ++++++++++++++-- src/backend/executor/nodeSeqscan.c | 26 ++++++++++++++++++++--- src/backend/partitioning/partbounds.c | 2 +- src/backend/utils/adt/selfuncs.c | 2 +- src/include/access/genam.h | 2 +- src/include/access/heapam.h | 6 ++++++ src/include/access/tableam.h | 19 ++++++++++------- 23 files changed, 107 insertions(+), 46 deletions(-) diff --git a/contrib/pgrowlocks/pgrowlocks.c b/contrib/pgrowlocks/pgrowlocks.c index f88269332b6..27f01d8055f 100644 --- a/contrib/pgrowlocks/pgrowlocks.c +++ b/contrib/pgrowlocks/pgrowlocks.c @@ -114,7 +114,7 @@ pgrowlocks(PG_FUNCTION_ARGS) RelationGetRelationName(rel)); /* Scan the relation */ - scan = table_beginscan(rel, GetActiveSnapshot(), 0, NULL); + scan = table_beginscan(rel, GetActiveSnapshot(), 0, NULL, 0); hscan = (HeapScanDesc) scan; attinmeta = TupleDescGetAttInMetadata(rsinfo->setDesc); diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c index 6887e421442..4d9684b1b19 100644 --- a/src/backend/access/brin/brin.c +++ b/src/backend/access/brin/brin.c @@ -2843,7 +2843,8 @@ _brin_parallel_scan_and_build(BrinBuildState *state, indexInfo->ii_Concurrent = brinshared->isconcurrent; scan = table_beginscan_parallel(heap, - ParallelTableScanFromBrinShared(brinshared)); + ParallelTableScanFromBrinShared(brinshared), + 0); reltuples = table_index_build_scan(heap, index, indexInfo, true, true, brinbuildCallbackParallel, state, scan); diff --git a/src/backend/access/gin/gininsert.c b/src/backend/access/gin/gininsert.c index 0d63fb4ba27..f02d6df40a2 100644 --- a/src/backend/access/gin/gininsert.c +++ b/src/backend/access/gin/gininsert.c @@ -2059,7 +2059,8 @@ _gin_parallel_scan_and_build(GinBuildState *state, indexInfo->ii_Concurrent = ginshared->isconcurrent; scan = table_beginscan_parallel(heap, - ParallelTableScanFromGinBuildShared(ginshared)); + ParallelTableScanFromGinBuildShared(ginshared), + 0); reltuples = table_index_build_scan(heap, index, indexInfo, true, progress, ginBuildCallbackParallel, state, scan); diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c index da4ae236ca8..6ce4350c2c8 100644 --- a/src/backend/access/heap/heapam_handler.c +++ b/src/backend/access/heap/heapam_handler.c @@ -79,12 +79,13 @@ heapam_slot_callbacks(Relation relation) */ static IndexFetchTableData * -heapam_index_fetch_begin(Relation rel) +heapam_index_fetch_begin(Relation rel, uint32 flags) { IndexFetchHeapData *hscan = palloc0_object(IndexFetchHeapData); hscan->xs_base.rel = rel; hscan->xs_cbuf = InvalidBuffer; + hscan->modifies_base_rel = !(flags & SO_HINT_REL_READ_ONLY); return &hscan->xs_base; } @@ -753,7 +754,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap, tableScan = NULL; heapScan = NULL; - indexScan = index_beginscan(OldHeap, OldIndex, SnapshotAny, NULL, 0, 0); + indexScan = index_beginscan(OldHeap, OldIndex, SnapshotAny, NULL, 0, 0, 0); index_rescan(indexScan, NULL, 0, NULL, 0); } else @@ -762,7 +763,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap, pgstat_progress_update_param(PROGRESS_CLUSTER_PHASE, PROGRESS_CLUSTER_PHASE_SEQ_SCAN_HEAP); - tableScan = table_beginscan(OldHeap, SnapshotAny, 0, (ScanKey) NULL); + tableScan = table_beginscan(OldHeap, SnapshotAny, 0, (ScanKey) NULL, 0); heapScan = (HeapScanDesc) tableScan; indexScan = NULL; diff --git a/src/backend/access/index/genam.c b/src/backend/access/index/genam.c index a29be6f467b..5ac7d22e49f 100644 --- a/src/backend/access/index/genam.c +++ b/src/backend/access/index/genam.c @@ -447,7 +447,7 @@ systable_beginscan(Relation heapRelation, } sysscan->iscan = index_beginscan(heapRelation, irel, - snapshot, NULL, nkeys, 0); + snapshot, NULL, nkeys, 0, 0); index_rescan(sysscan->iscan, idxkey, nkeys, NULL, 0); sysscan->scan = NULL; @@ -708,7 +708,7 @@ systable_beginscan_ordered(Relation heapRelation, } sysscan->iscan = index_beginscan(heapRelation, indexRelation, - snapshot, NULL, nkeys, 0); + snapshot, NULL, nkeys, 0, 0); index_rescan(sysscan->iscan, idxkey, nkeys, NULL, 0); sysscan->scan = NULL; diff --git a/src/backend/access/index/indexam.c b/src/backend/access/index/indexam.c index 4ed0508c605..4df56087841 100644 --- a/src/backend/access/index/indexam.c +++ b/src/backend/access/index/indexam.c @@ -257,7 +257,7 @@ index_beginscan(Relation heapRelation, Relation indexRelation, Snapshot snapshot, IndexScanInstrumentation *instrument, - int nkeys, int norderbys) + int nkeys, int norderbys, uint32 flags) { IndexScanDesc scan; @@ -284,7 +284,7 @@ index_beginscan(Relation heapRelation, scan->instrument = instrument; /* prepare to fetch index matches from table */ - scan->xs_heapfetch = table_index_fetch_begin(heapRelation); + scan->xs_heapfetch = table_index_fetch_begin(heapRelation, flags); return scan; } @@ -615,7 +615,7 @@ index_beginscan_parallel(Relation heaprel, Relation indexrel, scan->instrument = instrument; /* prepare to fetch index matches from table */ - scan->xs_heapfetch = table_index_fetch_begin(heaprel); + scan->xs_heapfetch = table_index_fetch_begin(heaprel, 0); return scan; } diff --git a/src/backend/access/nbtree/nbtsort.c b/src/backend/access/nbtree/nbtsort.c index 90ab4e91b56..8ae54217f36 100644 --- a/src/backend/access/nbtree/nbtsort.c +++ b/src/backend/access/nbtree/nbtsort.c @@ -1925,7 +1925,7 @@ _bt_parallel_scan_and_sort(BTSpool *btspool, BTSpool *btspool2, indexInfo = BuildIndexInfo(btspool->index); indexInfo->ii_Concurrent = btshared->isconcurrent; scan = table_beginscan_parallel(btspool->heap, - ParallelTableScanFromBTShared(btshared)); + ParallelTableScanFromBTShared(btshared), 0); reltuples = table_index_build_scan(btspool->heap, btspool->index, indexInfo, true, progress, _bt_build_callback, &buildstate, scan); diff --git a/src/backend/access/table/tableam.c b/src/backend/access/table/tableam.c index 87491796523..2ff29b6e40b 100644 --- a/src/backend/access/table/tableam.c +++ b/src/backend/access/table/tableam.c @@ -163,10 +163,11 @@ table_parallelscan_initialize(Relation rel, ParallelTableScanDesc pscan, } TableScanDesc -table_beginscan_parallel(Relation relation, ParallelTableScanDesc pscan) +table_beginscan_parallel(Relation relation, ParallelTableScanDesc pscan, uint32 flags) { Snapshot snapshot; - uint32 flags = SO_TYPE_SEQSCAN | + + flags |= SO_TYPE_SEQSCAN | SO_ALLOW_STRAT | SO_ALLOW_SYNC | SO_ALLOW_PAGEMODE; Assert(RelFileLocatorEquals(relation->rd_locator, pscan->phs_locator)); @@ -248,7 +249,7 @@ table_index_fetch_tuple_check(Relation rel, bool found; slot = table_slot_create(rel, NULL); - scan = table_index_fetch_begin(rel); + scan = table_index_fetch_begin(rel, 0); found = table_index_fetch_tuple(scan, tid, snapshot, slot, &call_again, all_dead); table_index_fetch_end(scan); diff --git a/src/backend/commands/constraint.c b/src/backend/commands/constraint.c index cc11c47b6f2..37cfbd63938 100644 --- a/src/backend/commands/constraint.c +++ b/src/backend/commands/constraint.c @@ -106,7 +106,7 @@ unique_key_recheck(PG_FUNCTION_ARGS) */ tmptid = checktid; { - IndexFetchTableData *scan = table_index_fetch_begin(trigdata->tg_relation); + IndexFetchTableData *scan = table_index_fetch_begin(trigdata->tg_relation, 0); bool call_again = false; if (!table_index_fetch_tuple(scan, &tmptid, SnapshotSelf, slot, diff --git a/src/backend/commands/copyto.c b/src/backend/commands/copyto.c index 4ab4a3893d5..4261baf4a41 100644 --- a/src/backend/commands/copyto.c +++ b/src/backend/commands/copyto.c @@ -1156,7 +1156,7 @@ CopyRelationTo(CopyToState cstate, Relation rel, Relation root_rel, uint64 *proc AttrMap *map = NULL; TupleTableSlot *root_slot = NULL; - scandesc = table_beginscan(rel, GetActiveSnapshot(), 0, NULL); + scandesc = table_beginscan(rel, GetActiveSnapshot(), 0, NULL, 0); slot = table_slot_create(rel, NULL); /* diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index f976c0e5c7e..eb35dbbc853 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -6378,7 +6378,7 @@ ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap) * checking all the constraints. */ snapshot = RegisterSnapshot(GetLatestSnapshot()); - scan = table_beginscan(oldrel, snapshot, 0, NULL); + scan = table_beginscan(oldrel, snapshot, 0, NULL, 0); /* * Switch to per-tuple memory context and reset it for each tuple @@ -13768,7 +13768,7 @@ validateForeignKeyConstraint(char *conname, */ snapshot = RegisterSnapshot(GetLatestSnapshot()); slot = table_slot_create(rel, NULL); - scan = table_beginscan(rel, snapshot, 0, NULL); + scan = table_beginscan(rel, snapshot, 0, NULL, 0); perTupCxt = AllocSetContextCreate(CurrentMemoryContext, "validateForeignKeyConstraint", @@ -22626,7 +22626,7 @@ MergePartitionsMoveRows(List **wqueue, List *mergingPartitions, Relation newPart /* Scan through the rows. */ snapshot = RegisterSnapshot(GetLatestSnapshot()); - scan = table_beginscan(mergingPartition, snapshot, 0, NULL); + scan = table_beginscan(mergingPartition, snapshot, 0, NULL, 0); /* * Switch to per-tuple memory context and reset it for each tuple @@ -23090,7 +23090,7 @@ SplitPartitionMoveRows(List **wqueue, Relation rel, Relation splitRel, /* Scan through the rows. */ snapshot = RegisterSnapshot(GetLatestSnapshot()); - scan = table_beginscan(splitRel, snapshot, 0, NULL); + scan = table_beginscan(splitRel, snapshot, 0, NULL, 0); /* * Switch to per-tuple memory context and reset it for each tuple diff --git a/src/backend/commands/typecmds.c b/src/backend/commands/typecmds.c index 288edb25f2f..34ff8d041f1 100644 --- a/src/backend/commands/typecmds.c +++ b/src/backend/commands/typecmds.c @@ -3179,7 +3179,7 @@ validateDomainNotNullConstraint(Oid domainoid) /* Scan all tuples in this relation */ snapshot = RegisterSnapshot(GetLatestSnapshot()); - scan = table_beginscan(testrel, snapshot, 0, NULL); + scan = table_beginscan(testrel, snapshot, 0, NULL, 0); slot = table_slot_create(testrel, NULL); while (table_scan_getnextslot(scan, ForwardScanDirection, slot)) { @@ -3260,7 +3260,7 @@ validateDomainCheckConstraint(Oid domainoid, const char *ccbin, LOCKMODE lockmod /* Scan all tuples in this relation */ snapshot = RegisterSnapshot(GetLatestSnapshot()); - scan = table_beginscan(testrel, snapshot, 0, NULL); + scan = table_beginscan(testrel, snapshot, 0, NULL, 0); slot = table_slot_create(testrel, NULL); while (table_scan_getnextslot(scan, ForwardScanDirection, slot)) { diff --git a/src/backend/executor/execIndexing.c b/src/backend/executor/execIndexing.c index 6ae0f959592..6d3e9d2f311 100644 --- a/src/backend/executor/execIndexing.c +++ b/src/backend/executor/execIndexing.c @@ -816,7 +816,7 @@ check_exclusion_or_unique_constraint(Relation heap, Relation index, retry: conflict = false; found_self = false; - index_scan = index_beginscan(heap, index, &DirtySnapshot, NULL, indnkeyatts, 0); + index_scan = index_beginscan(heap, index, &DirtySnapshot, NULL, indnkeyatts, 0, 0); index_rescan(index_scan, scankeys, indnkeyatts, NULL, 0); while (index_getnext_slot(index_scan, ForwardScanDirection, existing_slot)) diff --git a/src/backend/executor/execReplication.c b/src/backend/executor/execReplication.c index 72f2bff7708..4c965a35e05 100644 --- a/src/backend/executor/execReplication.c +++ b/src/backend/executor/execReplication.c @@ -205,7 +205,7 @@ RelationFindReplTupleByIndex(Relation rel, Oid idxoid, skey_attoff = build_replindex_scan_key(skey, rel, idxrel, searchslot); /* Start an index scan. */ - scan = index_beginscan(rel, idxrel, &snap, NULL, skey_attoff, 0); + scan = index_beginscan(rel, idxrel, &snap, NULL, skey_attoff, 0, 0); retry: found = false; @@ -383,7 +383,7 @@ RelationFindReplTupleSeq(Relation rel, LockTupleMode lockmode, /* Start a heap scan. */ InitDirtySnapshot(snap); - scan = table_beginscan(rel, &snap, 0, NULL); + scan = table_beginscan(rel, &snap, 0, NULL, 0); scanslot = table_slot_create(rel, NULL); retry: @@ -602,7 +602,7 @@ RelationFindDeletedTupleInfoSeq(Relation rel, TupleTableSlot *searchslot, * not yet committed or those just committed prior to the scan are * excluded in update_most_recent_deletion_info(). */ - scan = table_beginscan(rel, SnapshotAny, 0, NULL); + scan = table_beginscan(rel, SnapshotAny, 0, NULL, 0); scanslot = table_slot_create(rel, NULL); table_rescan(scan, NULL); @@ -666,7 +666,7 @@ RelationFindDeletedTupleInfoByIndex(Relation rel, Oid idxoid, * not yet committed or those just committed prior to the scan are * excluded in update_most_recent_deletion_info(). */ - scan = index_beginscan(rel, idxrel, SnapshotAny, NULL, skey_attoff, 0); + scan = index_beginscan(rel, idxrel, SnapshotAny, NULL, skey_attoff, 0, 0); index_rescan(scan, skey, skey_attoff, NULL, 0); diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c index c68c26cbf38..1017676fce0 100644 --- a/src/backend/executor/nodeBitmapHeapscan.c +++ b/src/backend/executor/nodeBitmapHeapscan.c @@ -103,11 +103,18 @@ BitmapTableScanSetup(BitmapHeapScanState *node) */ if (!node->ss.ss_currentScanDesc) { + uint32 flags = 0; + + if (!bms_is_member(((Scan *) node->ss.ps.plan)->scanrelid, + node->ss.ps.state->es_modified_relids)) + flags = SO_HINT_REL_READ_ONLY; + node->ss.ss_currentScanDesc = table_beginscan_bm(node->ss.ss_currentRelation, node->ss.ps.state->es_snapshot, 0, - NULL); + NULL, + flags); } node->ss.ss_currentScanDesc->st.rs_tbmiterator = tbmiterator; diff --git a/src/backend/executor/nodeIndexonlyscan.c b/src/backend/executor/nodeIndexonlyscan.c index c2d09374517..2fe724a323f 100644 --- a/src/backend/executor/nodeIndexonlyscan.c +++ b/src/backend/executor/nodeIndexonlyscan.c @@ -84,6 +84,12 @@ IndexOnlyNext(IndexOnlyScanState *node) if (scandesc == NULL) { + uint32 flags = 0; + + if (!bms_is_member(((Scan *) node->ss.ps.plan)->scanrelid, + estate->es_modified_relids)) + flags = SO_HINT_REL_READ_ONLY; + /* * We reach here if the index only scan is not parallel, or if we're * serially executing an index only scan that was planned to be @@ -94,7 +100,8 @@ IndexOnlyNext(IndexOnlyScanState *node) estate->es_snapshot, &node->ioss_Instrument, node->ioss_NumScanKeys, - node->ioss_NumOrderByKeys); + node->ioss_NumOrderByKeys, + flags); node->ioss_ScanDesc = scandesc; diff --git a/src/backend/executor/nodeIndexscan.c b/src/backend/executor/nodeIndexscan.c index a616abff04c..8730dab7469 100644 --- a/src/backend/executor/nodeIndexscan.c +++ b/src/backend/executor/nodeIndexscan.c @@ -102,6 +102,12 @@ IndexNext(IndexScanState *node) if (scandesc == NULL) { + uint32 flags = 0; + + if (!bms_is_member(((Scan *) node->ss.ps.plan)->scanrelid, + estate->es_modified_relids)) + flags = SO_HINT_REL_READ_ONLY; + /* * We reach here if the index scan is not parallel, or if we're * serially executing an index scan that was planned to be parallel. @@ -111,7 +117,8 @@ IndexNext(IndexScanState *node) estate->es_snapshot, &node->iss_Instrument, node->iss_NumScanKeys, - node->iss_NumOrderByKeys); + node->iss_NumOrderByKeys, + flags); node->iss_ScanDesc = scandesc; @@ -198,6 +205,12 @@ IndexNextWithReorder(IndexScanState *node) if (scandesc == NULL) { + uint32 flags = 0; + + if (!bms_is_member(((Scan *) node->ss.ps.plan)->scanrelid, + estate->es_modified_relids)) + flags = SO_HINT_REL_READ_ONLY; + /* * We reach here if the index scan is not parallel, or if we're * serially executing an index scan that was planned to be parallel. @@ -207,7 +220,8 @@ IndexNextWithReorder(IndexScanState *node) estate->es_snapshot, &node->iss_Instrument, node->iss_NumScanKeys, - node->iss_NumOrderByKeys); + node->iss_NumOrderByKeys, + flags); node->iss_ScanDesc = scandesc; diff --git a/src/backend/executor/nodeSeqscan.c b/src/backend/executor/nodeSeqscan.c index af3c788ce8b..336354922a2 100644 --- a/src/backend/executor/nodeSeqscan.c +++ b/src/backend/executor/nodeSeqscan.c @@ -65,13 +65,20 @@ SeqNext(SeqScanState *node) if (scandesc == NULL) { + uint32 flags = 0; + + if (!bms_is_member(((Scan *) node->ss.ps.plan)->scanrelid, + estate->es_modified_relids)) + flags = SO_HINT_REL_READ_ONLY; + /* * We reach here if the scan is not parallel, or if we're serially * executing a scan that was planned to be parallel. */ scandesc = table_beginscan(node->ss.ss_currentRelation, estate->es_snapshot, - 0, NULL); + 0, NULL, flags); + node->ss.ss_currentScanDesc = scandesc; } @@ -367,14 +374,20 @@ ExecSeqScanInitializeDSM(SeqScanState *node, { EState *estate = node->ss.ps.state; ParallelTableScanDesc pscan; + uint32 flags = 0; pscan = shm_toc_allocate(pcxt->toc, node->pscan_len); table_parallelscan_initialize(node->ss.ss_currentRelation, pscan, estate->es_snapshot); shm_toc_insert(pcxt->toc, node->ss.ps.plan->plan_node_id, pscan); + if (!bms_is_member(((Scan *) node->ss.ps.plan)->scanrelid, + estate->es_modified_relids)) + flags = SO_HINT_REL_READ_ONLY; + node->ss.ss_currentScanDesc = - table_beginscan_parallel(node->ss.ss_currentRelation, pscan); + table_beginscan_parallel(node->ss.ss_currentRelation, pscan, + flags); } /* ---------------------------------------------------------------- @@ -404,8 +417,15 @@ ExecSeqScanInitializeWorker(SeqScanState *node, ParallelWorkerContext *pwcxt) { ParallelTableScanDesc pscan; + uint32 flags = 0; + + if (!bms_is_member(((Scan *) node->ss.ps.plan)->scanrelid, + node->ss.ps.state->es_modified_relids)) + flags = SO_HINT_REL_READ_ONLY; pscan = shm_toc_lookup(pwcxt->toc, node->ss.ps.plan->plan_node_id, false); node->ss.ss_currentScanDesc = - table_beginscan_parallel(node->ss.ss_currentRelation, pscan); + table_beginscan_parallel(node->ss.ss_currentRelation, + pscan, + flags); } diff --git a/src/backend/partitioning/partbounds.c b/src/backend/partitioning/partbounds.c index 0ca312ac27d..b7c4e6d1071 100644 --- a/src/backend/partitioning/partbounds.c +++ b/src/backend/partitioning/partbounds.c @@ -3362,7 +3362,7 @@ check_default_partition_contents(Relation parent, Relation default_rel, econtext = GetPerTupleExprContext(estate); snapshot = RegisterSnapshot(GetLatestSnapshot()); tupslot = table_slot_create(part_rel, &estate->es_tupleTable); - scan = table_beginscan(part_rel, snapshot, 0, NULL); + scan = table_beginscan(part_rel, snapshot, 0, NULL, 0); /* * Switch to per-tuple memory context and reset it for each tuple diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c index 29fec655593..ac181853225 100644 --- a/src/backend/utils/adt/selfuncs.c +++ b/src/backend/utils/adt/selfuncs.c @@ -7181,7 +7181,7 @@ get_actual_variable_endpoint(Relation heapRel, index_scan = index_beginscan(heapRel, indexRel, &SnapshotNonVacuumable, NULL, - 1, 0); + 1, 0, 0); /* Set it up for index-only scan */ index_scan->xs_want_itup = true; index_rescan(index_scan, scankeys, 1, NULL, 0); diff --git a/src/include/access/genam.h b/src/include/access/genam.h index 4c0429cc613..3934fa44793 100644 --- a/src/include/access/genam.h +++ b/src/include/access/genam.h @@ -156,7 +156,7 @@ extern IndexScanDesc index_beginscan(Relation heapRelation, Relation indexRelation, Snapshot snapshot, IndexScanInstrumentation *instrument, - int nkeys, int norderbys); + int nkeys, int norderbys, uint32 flags); extern IndexScanDesc index_beginscan_bitmap(Relation indexRelation, Snapshot snapshot, IndexScanInstrumentation *instrument, diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h index 05ef8d8cd5e..6d54781609a 100644 --- a/src/include/access/heapam.h +++ b/src/include/access/heapam.h @@ -119,6 +119,12 @@ typedef struct IndexFetchHeapData Buffer xs_cbuf; /* current heap buffer in scan, if any */ /* NB: if xs_cbuf is not InvalidBuffer, we hold a pin on that buffer */ + + /* + * Some optimizations can only be performed if the query does not modify + * the underlying relation. Track that here. + */ + bool modifies_base_rel; } IndexFetchHeapData; /* Result codes for HeapTupleSatisfiesVacuum */ diff --git a/src/include/access/tableam.h b/src/include/access/tableam.h index c9fa9f259cd..fb2a54b010d 100644 --- a/src/include/access/tableam.h +++ b/src/include/access/tableam.h @@ -63,6 +63,8 @@ typedef enum ScanOptions /* unregister snapshot at scan end? */ SO_TEMP_SNAPSHOT = 1 << 9, + /* set if the query doesn't modify the relation */ + SO_HINT_REL_READ_ONLY = 1 << 10, } ScanOptions; /* @@ -420,7 +422,7 @@ typedef struct TableAmRoutine * * Tuples for an index scan can then be fetched via index_fetch_tuple. */ - struct IndexFetchTableData *(*index_fetch_begin) (Relation rel); + struct IndexFetchTableData *(*index_fetch_begin) (Relation rel, uint32 flags); /* * Reset index fetch. Typically this will release cross index fetch @@ -873,9 +875,9 @@ extern TupleTableSlot *table_slot_create(Relation relation, List **reglist); */ static inline TableScanDesc table_beginscan(Relation rel, Snapshot snapshot, - int nkeys, ScanKeyData *key) + int nkeys, ScanKeyData *key, uint32 flags) { - uint32 flags = SO_TYPE_SEQSCAN | + flags |= SO_TYPE_SEQSCAN | SO_ALLOW_STRAT | SO_ALLOW_SYNC | SO_ALLOW_PAGEMODE; return rel->rd_tableam->scan_begin(rel, snapshot, nkeys, key, NULL, flags); @@ -918,9 +920,9 @@ table_beginscan_strat(Relation rel, Snapshot snapshot, */ static inline TableScanDesc table_beginscan_bm(Relation rel, Snapshot snapshot, - int nkeys, ScanKeyData *key) + int nkeys, ScanKeyData *key, uint32 flags) { - uint32 flags = SO_TYPE_BITMAPSCAN | SO_ALLOW_PAGEMODE; + flags |= SO_TYPE_BITMAPSCAN | SO_ALLOW_PAGEMODE; return rel->rd_tableam->scan_begin(rel, snapshot, nkeys, key, NULL, flags); @@ -1127,7 +1129,8 @@ extern void table_parallelscan_initialize(Relation rel, * Caller must hold a suitable lock on the relation. */ extern TableScanDesc table_beginscan_parallel(Relation relation, - ParallelTableScanDesc pscan); + ParallelTableScanDesc pscan, + uint32 flags); /* * Begin a parallel tid range scan. `pscan` needs to have been initialized @@ -1163,9 +1166,9 @@ table_parallelscan_reinitialize(Relation rel, ParallelTableScanDesc pscan) * Tuples for an index scan can then be fetched via table_index_fetch_tuple(). */ static inline IndexFetchTableData * -table_index_fetch_begin(Relation rel) +table_index_fetch_begin(Relation rel, uint32 flags) { - return rel->rd_tableam->index_fetch_begin(rel); + return rel->rd_tableam->index_fetch_begin(rel, flags); } /* -- 2.43.0