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[PATCH] Set PD_ALL_VISIBLE and visibility map bits in COPY FREEZE 17+ messages / 2 participants [nested] [flat]
* [PATCH] Set PD_ALL_VISIBLE and visibility map bits in COPY FREEZE @ 2021-01-10 19:30 Tomas Vondra <[email protected]> 0 siblings, 0 replies; 17+ messages in thread From: Tomas Vondra @ 2021-01-10 19:30 UTC (permalink / raw) Make sure COPY FREEZE marks the pages as PD_ALL_VISIBLE and updates the visibility map. Until now it only marked individual tuples as frozen, but page-level flags were not updated. This is a fairly old patch, and multiple people worked on it. The first version was written by Jeff Janes, and then reworked by Pavan Deolasee and Anastasia Lubennikova. Author: Pavan Deolasee, Anastasia Lubennikova, Jeff Janes Reviewed-by: Kuntal Ghosh, Jeff Janes, Tomas Vondra, Masahiko Sawada, Andres Freund, Ibrar Ahmed, Robert Haas, Tatsuro Ishii Discussion: https://postgr.es/m/CABOikdN-ptGv0mZntrK2Q8OtfUuAjqaYMGmkdU1dCKFtUxVLrg@mail.gmail.com Discussion: https://postgr.es/m/CAMkU%3D1w3osJJ2FneELhhNRLxfZitDgp9FPHee08NT2FQFmz_pQ%40mail.gmail.com --- .../pg_visibility/expected/pg_visibility.out | 64 +++++++++++++++ contrib/pg_visibility/sql/pg_visibility.sql | 77 +++++++++++++++++++ src/backend/access/heap/heapam.c | 76 ++++++++++++++++-- src/backend/access/heap/hio.c | 17 ++++ src/include/access/heapam_xlog.h | 3 + 5 files changed, 229 insertions(+), 8 deletions(-) diff --git a/contrib/pg_visibility/expected/pg_visibility.out b/contrib/pg_visibility/expected/pg_visibility.out index ca4b6e186b..0017e3415c 100644 --- a/contrib/pg_visibility/expected/pg_visibility.out +++ b/contrib/pg_visibility/expected/pg_visibility.out @@ -179,6 +179,69 @@ select pg_truncate_visibility_map('test_partition'); (1 row) +-- test copy freeze +create table copyfreeze (a int, b char(1500)); +-- load all rows via COPY FREEZE and ensure that all pages are set all-visible +-- and all-frozen. +begin; +truncate copyfreeze; +copy copyfreeze from stdin freeze; +commit; +select * from pg_visibility_map('copyfreeze'); + blkno | all_visible | all_frozen +-------+-------------+------------ + 0 | t | t + 1 | t | t + 2 | t | t +(3 rows) + +select * from pg_check_frozen('copyfreeze'); + t_ctid +-------- +(0 rows) + +-- load half the rows via regular COPY and rest via COPY FREEZE. The pages +-- which are touched by regular COPY must not be set all-visible/all-frozen. On +-- the other hand, pages allocated by COPY FREEZE should be marked +-- all-frozen/all-visible. +begin; +truncate copyfreeze; +copy copyfreeze from stdin; +copy copyfreeze from stdin freeze; +commit; +select * from pg_visibility_map('copyfreeze'); + blkno | all_visible | all_frozen +-------+-------------+------------ + 0 | f | f + 1 | f | f + 2 | t | t +(3 rows) + +select * from pg_check_frozen('copyfreeze'); + t_ctid +-------- +(0 rows) + +-- Try a mix of regular COPY and COPY FREEZE. +begin; +truncate copyfreeze; +copy copyfreeze from stdin freeze; +copy copyfreeze from stdin; +copy copyfreeze from stdin freeze; +commit; +select * from pg_visibility_map('copyfreeze'); + blkno | all_visible | all_frozen +-------+-------------+------------ + 0 | t | t + 1 | f | f + 2 | t | t +(3 rows) + +select * from pg_check_frozen('copyfreeze'); + t_ctid +-------- +(0 rows) + -- cleanup drop table test_partitioned; drop view test_view; @@ -188,3 +251,4 @@ drop server dummy_server; drop foreign data wrapper dummy; drop materialized view matview_visibility_test; drop table regular_table; +drop table copyfreeze; diff --git a/contrib/pg_visibility/sql/pg_visibility.sql b/contrib/pg_visibility/sql/pg_visibility.sql index f79b54480b..ec1afd4906 100644 --- a/contrib/pg_visibility/sql/pg_visibility.sql +++ b/contrib/pg_visibility/sql/pg_visibility.sql @@ -94,6 +94,82 @@ select count(*) > 0 from pg_visibility_map_summary('test_partition'); select * from pg_check_frozen('test_partition'); -- hopefully none select pg_truncate_visibility_map('test_partition'); +-- test copy freeze +create table copyfreeze (a int, b char(1500)); + +-- load all rows via COPY FREEZE and ensure that all pages are set all-visible +-- and all-frozen. +begin; +truncate copyfreeze; +copy copyfreeze from stdin freeze; +1 '1' +2 '2' +3 '3' +4 '4' +5 '5' +6 '6' +7 '7' +8 '8' +9 '9' +10 '10' +11 '11' +12 '12' +\. +commit; +select * from pg_visibility_map('copyfreeze'); +select * from pg_check_frozen('copyfreeze'); + +-- load half the rows via regular COPY and rest via COPY FREEZE. The pages +-- which are touched by regular COPY must not be set all-visible/all-frozen. On +-- the other hand, pages allocated by COPY FREEZE should be marked +-- all-frozen/all-visible. +begin; +truncate copyfreeze; +copy copyfreeze from stdin; +1 '1' +2 '2' +3 '3' +4 '4' +5 '5' +6 '6' +\. +copy copyfreeze from stdin freeze; +7 '7' +8 '8' +9 '9' +10 '10' +11 '11' +12 '12' +\. +commit; +select * from pg_visibility_map('copyfreeze'); +select * from pg_check_frozen('copyfreeze'); + +-- Try a mix of regular COPY and COPY FREEZE. +begin; +truncate copyfreeze; +copy copyfreeze from stdin freeze; +1 '1' +2 '2' +3 '3' +4 '4' +5 '5' +\. +copy copyfreeze from stdin; +6 '6' +\. +copy copyfreeze from stdin freeze; +7 '7' +8 '8' +9 '9' +10 '10' +11 '11' +12 '12' +\. +commit; +select * from pg_visibility_map('copyfreeze'); +select * from pg_check_frozen('copyfreeze'); + -- cleanup drop table test_partitioned; drop view test_view; @@ -103,3 +179,4 @@ drop server dummy_server; drop foreign data wrapper dummy; drop materialized view matview_visibility_test; drop table regular_table; +drop table copyfreeze; diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c index 53e997cd55..32cc010cb7 100644 --- a/src/backend/access/heap/heapam.c +++ b/src/backend/access/heap/heapam.c @@ -2103,6 +2103,7 @@ heap_multi_insert(Relation relation, TupleTableSlot **slots, int ntuples, int ndone; PGAlignedBlock scratch; Page page; + Buffer vmbuffer = InvalidBuffer; bool needwal; Size saveFreeSpace; bool need_tuple_data = RelationIsLogicallyLogged(relation); @@ -2157,8 +2158,9 @@ heap_multi_insert(Relation relation, TupleTableSlot **slots, int ntuples, while (ndone < ntuples) { Buffer buffer; - Buffer vmbuffer = InvalidBuffer; + bool starting_with_empty_page; bool all_visible_cleared = false; + bool all_frozen_set = false; int nthispage; CHECK_FOR_INTERRUPTS(); @@ -2166,12 +2168,20 @@ heap_multi_insert(Relation relation, TupleTableSlot **slots, int ntuples, /* * Find buffer where at least the next tuple will fit. If the page is * all-visible, this will also pin the requisite visibility map page. + * + * Also pin visibility map page if COPY FREEZE inserts tuples into an + * empty page. See all_frozen_set below. */ buffer = RelationGetBufferForTuple(relation, heaptuples[ndone]->t_len, InvalidBuffer, options, bistate, &vmbuffer, NULL); page = BufferGetPage(buffer); + starting_with_empty_page = PageGetMaxOffsetNumber(page) == 0; + + if (starting_with_empty_page && (options & HEAP_INSERT_FROZEN)) + all_frozen_set = true; + /* NO EREPORT(ERROR) from here till changes are logged */ START_CRIT_SECTION(); @@ -2205,7 +2215,14 @@ heap_multi_insert(Relation relation, TupleTableSlot **slots, int ntuples, log_heap_new_cid(relation, heaptup); } - if (PageIsAllVisible(page)) + /* + * If the page is all visible, need to clear that, unless we're only + * going to add further frozen rows to it. + * + * If we're only adding already frozen rows to a previously empty + * page, mark it as all-visible. + */ + if (PageIsAllVisible(page) && !(options & HEAP_INSERT_FROZEN)) { all_visible_cleared = true; PageClearAllVisible(page); @@ -2213,6 +2230,8 @@ heap_multi_insert(Relation relation, TupleTableSlot **slots, int ntuples, BufferGetBlockNumber(buffer), vmbuffer, VISIBILITYMAP_VALID_BITS); } + else if (all_frozen_set) + PageSetAllVisible(page); /* * XXX Should we set PageSetPrunable on this page ? See heap_insert() @@ -2236,8 +2255,7 @@ heap_multi_insert(Relation relation, TupleTableSlot **slots, int ntuples, * If the page was previously empty, we can reinit the page * instead of restoring the whole thing. */ - init = (ItemPointerGetOffsetNumber(&(heaptuples[ndone]->t_self)) == FirstOffsetNumber && - PageGetMaxOffsetNumber(page) == FirstOffsetNumber + nthispage - 1); + init = starting_with_empty_page; /* allocate xl_heap_multi_insert struct from the scratch area */ xlrec = (xl_heap_multi_insert *) scratchptr; @@ -2255,7 +2273,15 @@ heap_multi_insert(Relation relation, TupleTableSlot **slots, int ntuples, /* the rest of the scratch space is used for tuple data */ tupledata = scratchptr; - xlrec->flags = all_visible_cleared ? XLH_INSERT_ALL_VISIBLE_CLEARED : 0; + /* check that the mutually exclusive flags are not both set */ + Assert (!(all_visible_cleared && all_frozen_set)); + + xlrec->flags = 0; + if (all_visible_cleared) + xlrec->flags = XLH_INSERT_ALL_VISIBLE_CLEARED; + if (all_frozen_set) + xlrec->flags = XLH_INSERT_ALL_FROZEN_SET; + xlrec->ntuples = nthispage; /* @@ -2329,13 +2355,39 @@ heap_multi_insert(Relation relation, TupleTableSlot **slots, int ntuples, END_CRIT_SECTION(); - UnlockReleaseBuffer(buffer); - if (vmbuffer != InvalidBuffer) - ReleaseBuffer(vmbuffer); + /* + * If we've frozen everything on the page, update the visibilitymap. + * We're already holding pin on the vmbuffer. + */ + if (all_frozen_set) + { + Assert(PageIsAllVisible(page)); + Assert(visibilitymap_pin_ok(BufferGetBlockNumber(buffer), vmbuffer)); + /* + * It's fine to use InvalidTransactionId here - this is only used + * when HEAP_INSERT_FROZEN is specified, which intentionally + * violates visibility rules. + */ + visibilitymap_set(relation, BufferGetBlockNumber(buffer), buffer, + InvalidXLogRecPtr, vmbuffer, + InvalidTransactionId, + VISIBILITYMAP_ALL_VISIBLE | VISIBILITYMAP_ALL_FROZEN); + } + + UnlockReleaseBuffer(buffer); ndone += nthispage; + + /* + * NB: Only release vmbuffer after inserting all tuples - it's fairly + * likely that we'll insert into subsequent heap pages that are likely + * to use the same vm page. + */ } + if (vmbuffer != InvalidBuffer) + ReleaseBuffer(vmbuffer); + /* * We're done with the actual inserts. Check for conflicts again, to * ensure that all rw-conflicts in to these inserts are detected. Without @@ -8265,6 +8317,10 @@ heap_xlog_multi_insert(XLogReaderState *record) XLogRecGetBlockTag(record, 0, &rnode, NULL, &blkno); + /* check that the mutually exclusive flags are not both set */ + Assert (!((xlrec->flags & XLH_INSERT_ALL_VISIBLE_CLEARED) && + (xlrec->flags & XLH_INSERT_ALL_FROZEN_SET))); + /* * The visibility map may need to be fixed even if the heap page is * already up-to-date. @@ -8354,6 +8410,10 @@ heap_xlog_multi_insert(XLogReaderState *record) if (xlrec->flags & XLH_INSERT_ALL_VISIBLE_CLEARED) PageClearAllVisible(page); + /* XLH_INSERT_ALL_FROZEN_SET implies that all tuples are visible */ + if (xlrec->flags & XLH_INSERT_ALL_FROZEN_SET) + PageSetAllVisible(page); + MarkBufferDirty(buffer); } if (BufferIsValid(buffer)) diff --git a/src/backend/access/heap/hio.c b/src/backend/access/heap/hio.c index fac3b8e9ff..2d23b3ef71 100644 --- a/src/backend/access/heap/hio.c +++ b/src/backend/access/heap/hio.c @@ -433,6 +433,14 @@ loop: buffer = ReadBufferBI(relation, targetBlock, RBM_NORMAL, bistate); if (PageIsAllVisible(BufferGetPage(buffer))) visibilitymap_pin(relation, targetBlock, vmbuffer); + + /* + * If the page is empty, pin vmbuffer to set all_frozen bit later. + */ + if ((options & HEAP_INSERT_FROZEN) && + (PageGetMaxOffsetNumber(BufferGetPage(buffer)) == 0)) + visibilitymap_pin(relation, targetBlock, vmbuffer); + LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE); } else if (otherBlock == targetBlock) @@ -619,6 +627,15 @@ loop: PageInit(page, BufferGetPageSize(buffer), 0); MarkBufferDirty(buffer); + /* + * The page is empty, pin vmbuffer to set all_frozen bit. + */ + if (options & HEAP_INSERT_FROZEN) + { + Assert(PageGetMaxOffsetNumber(BufferGetPage(buffer)) == 0); + visibilitymap_pin(relation, BufferGetBlockNumber(buffer), vmbuffer); + } + /* * Release the file-extension lock; it's now OK for someone else to extend * the relation some more. diff --git a/src/include/access/heapam_xlog.h b/src/include/access/heapam_xlog.h index 51586b883d..178d49710a 100644 --- a/src/include/access/heapam_xlog.h +++ b/src/include/access/heapam_xlog.h @@ -69,6 +69,9 @@ #define XLH_INSERT_CONTAINS_NEW_TUPLE (1<<3) #define XLH_INSERT_ON_TOAST_RELATION (1<<4) +/* all_frozen_set always implies all_visible_set */ +#define XLH_INSERT_ALL_FROZEN_SET (1<<5) + /* * xl_heap_update flag values, 8 bits are available. */ -- 2.26.2 --------------B3374ACE3BEE92372E040736 Content-Type: application/sql; name="test.sql" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="test.sql" Y3JlYXRlIGV4dGVuc2lvbiBwZ192aXNpYmlsaXR5OwoKZHJvcCB0YWJsZSBpZiBleGlzdHMg dDsKY3JlYXRlIHRhYmxlIHQgKGEgaW50LCBiIHRleHQpOwppbnNlcnQgaW50byB0IHNlbGVj dCBpLCAoc2VsZWN0IHN0cmluZ19hZ2cobWQ1KHJhbmRvbSgpOjp0ZXh0KSwgJycpIGZyb20g Z2VuZXJhdGVfc2VyaWVzKDEsMTAwKSkgZnJvbSBnZW5lcmF0ZV9zZXJpZXMoMSwxMDAwMDAp IHMoaSk7CmNvcHkgdCB0byAnL3RtcC90LmRhdGEnOwpkcm9wIHRhYmxlIHQ7CgpiZWdpbjsK Y3JlYXRlIHRhYmxlIHQgKGEgaW50LCBiIHRleHQpOwpjb3B5IHQgZnJvbSAnL3RtcC90LmRh dGEnIGZyZWV6ZTsKCnNlbGVjdCAqIGZyb20gcGdfdmlzaWJpbGl0eSgndCcpOwpzZWxlY3Qg KiBmcm9tIHBnX3Zpc2liaWxpdHkoKHNlbGVjdCByZWx0b2FzdHJlbGlkIGZyb20gcGdfY2xh c3Mgd2hlcmUgcmVsbmFtZSA9ICd0JykpOwoKCnNlbGVjdCBjb3VudCgqKSBmcm9tIHBnX3Zp c2liaWxpdHkoJ3QnKTsKc2VsZWN0IGNvdW50KCopIGZyb20gcGdfdmlzaWJpbGl0eSgndCcp IHdoZXJlIG5vdCBhbGxfdmlzaWJsZTsKCgpzZWxlY3QgY291bnQoKikgZnJvbSBwZ192aXNp YmlsaXR5KChzZWxlY3QgcmVsdG9hc3RyZWxpZCBmcm9tIHBnX2NsYXNzIHdoZXJlIHJlbG5h bWUgPSAndCcpKTsKc2VsZWN0IGNvdW50KCopIGZyb20gcGdfdmlzaWJpbGl0eSgoc2VsZWN0 IHJlbHRvYXN0cmVsaWQgZnJvbSBwZ19jbGFzcyB3aGVyZSByZWxuYW1lID0gJ3QnKSkgd2hl cmUgbm90IGFsbF92aXNpYmxlOwo= --------------B3374ACE3BEE92372E040736-- ^ permalink raw reply [nested|flat] 17+ messages in thread
* [PATCH v15 01/13] BitmapHeapScan begin scan after bitmap creation @ 2024-02-12 23:50 Melanie Plageman <[email protected]> 0 siblings, 0 replies; 17+ messages in thread From: Melanie Plageman @ 2024-02-12 23:50 UTC (permalink / raw) It makes more sense for BitmapHeapScan to scan the index, build the bitmap, and then begin the scan on the underlying table. This is primarily a cosmetic change for now, but later commits will pass parameters to table_beginscan_bm() that are unavailable in ExecInitBitmapHeapScan(). Author: Melanie Plageman Reviewed-by: Andres Freund, Heikki Linnakangas, Tomas Vondra Discussion: https://postgr.es/m/CAAKRu_ZwCwWFeL_H3ia26bP2e7HiKLWt0ZmGXPVwPO6uXq0vaA%40mail.gmail.com --- src/backend/executor/nodeBitmapHeapscan.c | 27 +++++++++++++++++------ 1 file changed, 20 insertions(+), 7 deletions(-) diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c index cee7f45aab..c8c466e3c5 100644 --- a/src/backend/executor/nodeBitmapHeapscan.c +++ b/src/backend/executor/nodeBitmapHeapscan.c @@ -178,6 +178,21 @@ BitmapHeapNext(BitmapHeapScanState *node) } #endif /* USE_PREFETCH */ } + + /* + * If this is the first scan of the underlying table, create the table + * scan descriptor and begin the scan. + */ + if (!scan) + { + scan = table_beginscan_bm(node->ss.ss_currentRelation, + node->ss.ps.state->es_snapshot, + 0, + NULL); + + node->ss.ss_currentScanDesc = scan; + } + node->initialized = true; } @@ -601,7 +616,8 @@ ExecReScanBitmapHeapScan(BitmapHeapScanState *node) PlanState *outerPlan = outerPlanState(node); /* rescan to release any page pin */ - table_rescan(node->ss.ss_currentScanDesc, NULL); + if (node->ss.ss_currentScanDesc) + table_rescan(node->ss.ss_currentScanDesc, NULL); /* release bitmaps and buffers if any */ if (node->tbmiterator) @@ -678,7 +694,9 @@ ExecEndBitmapHeapScan(BitmapHeapScanState *node) /* * close heap scan */ - table_endscan(scanDesc); + if (scanDesc) + table_endscan(scanDesc); + } /* ---------------------------------------------------------------- @@ -783,11 +801,6 @@ ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags) scanstate->ss.ss_currentRelation = currentRelation; - scanstate->ss.ss_currentScanDesc = table_beginscan_bm(currentRelation, - estate->es_snapshot, - 0, - NULL); - /* * all done. */ -- 2.40.1 --pbix6fw3h4kvmjae Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v15-0002-BitmapHeapScan-set-can_skip_fetch-later.patch" ^ permalink raw reply [nested|flat] 17+ messages in thread
* [PATCH v7 01/13] BitmapHeapScan begin scan after bitmap creation @ 2024-02-12 23:50 Melanie Plageman <[email protected]> 0 siblings, 0 replies; 17+ messages in thread From: Melanie Plageman @ 2024-02-12 23:50 UTC (permalink / raw) There is no reason for a BitmapHeapScan to begin the scan of the underlying table in ExecInitBitmapHeapScan(). Instead, do so after completing the index scan and building the bitmap. --- src/backend/access/table/tableam.c | 1 - src/backend/executor/nodeBitmapHeapscan.c | 26 +++++++++++++++++------ 2 files changed, 19 insertions(+), 8 deletions(-) diff --git a/src/backend/access/table/tableam.c b/src/backend/access/table/tableam.c index e57a0b7ea31..e78d793f69c 100644 --- a/src/backend/access/table/tableam.c +++ b/src/backend/access/table/tableam.c @@ -120,7 +120,6 @@ table_beginscan_catalog(Relation relation, int nkeys, struct ScanKeyData *key) NULL, flags); } - /* ---------------------------------------------------------------------------- * Parallel table scan related functions. * ---------------------------------------------------------------------------- diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c index cee7f45aabe..93fdcd226bf 100644 --- a/src/backend/executor/nodeBitmapHeapscan.c +++ b/src/backend/executor/nodeBitmapHeapscan.c @@ -178,6 +178,20 @@ BitmapHeapNext(BitmapHeapScanState *node) } #endif /* USE_PREFETCH */ } + + /* + * If this is the first scan of the underlying table, create the table + * scan descriptor and begin the scan. + */ + if (!scan) + { + scan = node->ss.ss_currentScanDesc = table_beginscan_bm( + node->ss.ss_currentRelation, + node->ss.ps.state->es_snapshot, + 0, + NULL); + } + node->initialized = true; } @@ -601,7 +615,8 @@ ExecReScanBitmapHeapScan(BitmapHeapScanState *node) PlanState *outerPlan = outerPlanState(node); /* rescan to release any page pin */ - table_rescan(node->ss.ss_currentScanDesc, NULL); + if (node->ss.ss_currentScanDesc) + table_rescan(node->ss.ss_currentScanDesc, NULL); /* release bitmaps and buffers if any */ if (node->tbmiterator) @@ -678,7 +693,9 @@ ExecEndBitmapHeapScan(BitmapHeapScanState *node) /* * close heap scan */ - table_endscan(scanDesc); + if (scanDesc) + table_endscan(scanDesc); + } /* ---------------------------------------------------------------- @@ -783,11 +800,6 @@ ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags) scanstate->ss.ss_currentRelation = currentRelation; - scanstate->ss.ss_currentScanDesc = table_beginscan_bm(currentRelation, - estate->es_snapshot, - 0, - NULL); - /* * all done. */ -- 2.40.1 --kqqpqghcwbcc3dt5 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v7-0002-BitmapHeapScan-set-can_skip_fetch-later.patch" ^ permalink raw reply [nested|flat] 17+ messages in thread
* [PATCH v13 01/16] BitmapHeapScan begin scan after bitmap creation @ 2024-02-12 23:50 Melanie Plageman <[email protected]> 0 siblings, 0 replies; 17+ messages in thread From: Melanie Plageman @ 2024-02-12 23:50 UTC (permalink / raw) There is no reason for a BitmapHeapScan to begin the scan of the underlying table in ExecInitBitmapHeapScan(). Instead, do so after completing the index scan and building the bitmap. --- src/backend/access/table/tableam.c | 1 - src/backend/executor/nodeBitmapHeapscan.c | 26 +++++++++++++++++------ 2 files changed, 19 insertions(+), 8 deletions(-) diff --git a/src/backend/access/table/tableam.c b/src/backend/access/table/tableam.c index 805d222ceb..b0f61c65f3 100644 --- a/src/backend/access/table/tableam.c +++ b/src/backend/access/table/tableam.c @@ -120,7 +120,6 @@ table_beginscan_catalog(Relation relation, int nkeys, struct ScanKeyData *key) NULL, flags); } - /* ---------------------------------------------------------------------------- * Parallel table scan related functions. * ---------------------------------------------------------------------------- diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c index cee7f45aab..93fdcd226b 100644 --- a/src/backend/executor/nodeBitmapHeapscan.c +++ b/src/backend/executor/nodeBitmapHeapscan.c @@ -178,6 +178,20 @@ BitmapHeapNext(BitmapHeapScanState *node) } #endif /* USE_PREFETCH */ } + + /* + * If this is the first scan of the underlying table, create the table + * scan descriptor and begin the scan. + */ + if (!scan) + { + scan = node->ss.ss_currentScanDesc = table_beginscan_bm( + node->ss.ss_currentRelation, + node->ss.ps.state->es_snapshot, + 0, + NULL); + } + node->initialized = true; } @@ -601,7 +615,8 @@ ExecReScanBitmapHeapScan(BitmapHeapScanState *node) PlanState *outerPlan = outerPlanState(node); /* rescan to release any page pin */ - table_rescan(node->ss.ss_currentScanDesc, NULL); + if (node->ss.ss_currentScanDesc) + table_rescan(node->ss.ss_currentScanDesc, NULL); /* release bitmaps and buffers if any */ if (node->tbmiterator) @@ -678,7 +693,9 @@ ExecEndBitmapHeapScan(BitmapHeapScanState *node) /* * close heap scan */ - table_endscan(scanDesc); + if (scanDesc) + table_endscan(scanDesc); + } /* ---------------------------------------------------------------- @@ -783,11 +800,6 @@ ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags) scanstate->ss.ss_currentRelation = currentRelation; - scanstate->ss.ss_currentScanDesc = table_beginscan_bm(currentRelation, - estate->es_snapshot, - 0, - NULL); - /* * all done. */ -- 2.40.1 --cuuqjeyokkhgd736 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v13-0002-BitmapHeapScan-set-can_skip_fetch-later.patch" ^ permalink raw reply [nested|flat] 17+ messages in thread
* [PATCH v19 01/21] BitmapHeapScan: begin scan after bitmap creation @ 2024-02-12 23:50 Melanie Plageman <[email protected]> 0 siblings, 0 replies; 17+ messages in thread From: Melanie Plageman @ 2024-02-12 23:50 UTC (permalink / raw) It makes more sense for BitmapHeapScan to scan the index, build the bitmap, and only then begin the scan on the underlying table. This is mostly a cosmetic change for now, but later commits will need to pass parameters to table_beginscan_bm() that are unavailable in ExecInitBitmapHeapScan(). Author: Melanie Plageman Reviewed-by: Tomas Vondra, Andres Freund, Heikki Linnakangas Discussion: https://postgr.es/m/CAAKRu_ZwCwWFeL_H3ia26bP2e7HiKLWt0ZmGXPVwPO6uXq0vaA%40mail.gmail.com --- src/backend/executor/nodeBitmapHeapscan.c | 27 +++++++++++++++++------ 1 file changed, 20 insertions(+), 7 deletions(-) diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c index cee7f45aabe..c8c466e3c5c 100644 --- a/src/backend/executor/nodeBitmapHeapscan.c +++ b/src/backend/executor/nodeBitmapHeapscan.c @@ -178,6 +178,21 @@ BitmapHeapNext(BitmapHeapScanState *node) } #endif /* USE_PREFETCH */ } + + /* + * If this is the first scan of the underlying table, create the table + * scan descriptor and begin the scan. + */ + if (!scan) + { + scan = table_beginscan_bm(node->ss.ss_currentRelation, + node->ss.ps.state->es_snapshot, + 0, + NULL); + + node->ss.ss_currentScanDesc = scan; + } + node->initialized = true; } @@ -601,7 +616,8 @@ ExecReScanBitmapHeapScan(BitmapHeapScanState *node) PlanState *outerPlan = outerPlanState(node); /* rescan to release any page pin */ - table_rescan(node->ss.ss_currentScanDesc, NULL); + if (node->ss.ss_currentScanDesc) + table_rescan(node->ss.ss_currentScanDesc, NULL); /* release bitmaps and buffers if any */ if (node->tbmiterator) @@ -678,7 +694,9 @@ ExecEndBitmapHeapScan(BitmapHeapScanState *node) /* * close heap scan */ - table_endscan(scanDesc); + if (scanDesc) + table_endscan(scanDesc); + } /* ---------------------------------------------------------------- @@ -783,11 +801,6 @@ ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags) scanstate->ss.ss_currentRelation = currentRelation; - scanstate->ss.ss_currentScanDesc = table_beginscan_bm(currentRelation, - estate->es_snapshot, - 0, - NULL); - /* * all done. */ -- 2.40.1 --clv5reqgj4vdihqz Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v19-0002-BitmapHeapScan-postpone-setting-can_skip_fetch.patch" ^ permalink raw reply [nested|flat] 17+ messages in thread
* [PATCH v6 01/14] BitmapHeapScan begin scan after bitmap creation @ 2024-02-12 23:50 Melanie Plageman <[email protected]> 0 siblings, 0 replies; 17+ messages in thread From: Melanie Plageman @ 2024-02-12 23:50 UTC (permalink / raw) There is no reason for a BitmapHeapScan to begin the scan of the underlying table in ExecInitBitmapHeapScan(). Instead, do so after completing the index scan and building the bitmap. --- src/backend/access/table/tableam.c | 1 - src/backend/executor/nodeBitmapHeapscan.c | 26 +++++++++++++++++------ 2 files changed, 19 insertions(+), 8 deletions(-) diff --git a/src/backend/access/table/tableam.c b/src/backend/access/table/tableam.c index e57a0b7ea31..e78d793f69c 100644 --- a/src/backend/access/table/tableam.c +++ b/src/backend/access/table/tableam.c @@ -120,7 +120,6 @@ table_beginscan_catalog(Relation relation, int nkeys, struct ScanKeyData *key) NULL, flags); } - /* ---------------------------------------------------------------------------- * Parallel table scan related functions. * ---------------------------------------------------------------------------- diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c index ca548e44eb4..6d756001fdb 100644 --- a/src/backend/executor/nodeBitmapHeapscan.c +++ b/src/backend/executor/nodeBitmapHeapscan.c @@ -178,6 +178,20 @@ BitmapHeapNext(BitmapHeapScanState *node) } #endif /* USE_PREFETCH */ } + + /* + * If this is the first scan of the underlying table, create the table + * scan descriptor and begin the scan. + */ + if (!scan) + { + scan = node->ss.ss_currentScanDesc = table_beginscan_bm( + node->ss.ss_currentRelation, + node->ss.ps.state->es_snapshot, + 0, + NULL); + } + node->initialized = true; } @@ -601,7 +615,8 @@ ExecReScanBitmapHeapScan(BitmapHeapScanState *node) PlanState *outerPlan = outerPlanState(node); /* rescan to release any page pin */ - table_rescan(node->ss.ss_currentScanDesc, NULL); + if (node->ss.ss_currentScanDesc) + table_rescan(node->ss.ss_currentScanDesc, NULL); /* release bitmaps and buffers if any */ if (node->tbmiterator) @@ -678,7 +693,9 @@ ExecEndBitmapHeapScan(BitmapHeapScanState *node) /* * close heap scan */ - table_endscan(scanDesc); + if (scanDesc) + table_endscan(scanDesc); + } /* ---------------------------------------------------------------- @@ -783,11 +800,6 @@ ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags) scanstate->ss.ss_currentRelation = currentRelation; - scanstate->ss.ss_currentScanDesc = table_beginscan_bm(currentRelation, - estate->es_snapshot, - 0, - NULL); - /* * all done. */ -- 2.40.1 --w4wcjcocxsm37usi Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v6-0002-BitmapHeapScan-set-can_skip_fetch-later.patch" ^ permalink raw reply [nested|flat] 17+ messages in thread
* [PATCH v8 01/17] BitmapHeapScan begin scan after bitmap creation @ 2024-02-12 23:50 Melanie Plageman <[email protected]> 0 siblings, 0 replies; 17+ messages in thread From: Melanie Plageman @ 2024-02-12 23:50 UTC (permalink / raw) There is no reason for a BitmapHeapScan to begin the scan of the underlying table in ExecInitBitmapHeapScan(). Instead, do so after completing the index scan and building the bitmap. --- src/backend/access/table/tableam.c | 1 - src/backend/executor/nodeBitmapHeapscan.c | 26 +++++++++++++++++------ 2 files changed, 19 insertions(+), 8 deletions(-) diff --git a/src/backend/access/table/tableam.c b/src/backend/access/table/tableam.c index e57a0b7ea3..e78d793f69 100644 --- a/src/backend/access/table/tableam.c +++ b/src/backend/access/table/tableam.c @@ -120,7 +120,6 @@ table_beginscan_catalog(Relation relation, int nkeys, struct ScanKeyData *key) NULL, flags); } - /* ---------------------------------------------------------------------------- * Parallel table scan related functions. * ---------------------------------------------------------------------------- diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c index cee7f45aab..93fdcd226b 100644 --- a/src/backend/executor/nodeBitmapHeapscan.c +++ b/src/backend/executor/nodeBitmapHeapscan.c @@ -178,6 +178,20 @@ BitmapHeapNext(BitmapHeapScanState *node) } #endif /* USE_PREFETCH */ } + + /* + * If this is the first scan of the underlying table, create the table + * scan descriptor and begin the scan. + */ + if (!scan) + { + scan = node->ss.ss_currentScanDesc = table_beginscan_bm( + node->ss.ss_currentRelation, + node->ss.ps.state->es_snapshot, + 0, + NULL); + } + node->initialized = true; } @@ -601,7 +615,8 @@ ExecReScanBitmapHeapScan(BitmapHeapScanState *node) PlanState *outerPlan = outerPlanState(node); /* rescan to release any page pin */ - table_rescan(node->ss.ss_currentScanDesc, NULL); + if (node->ss.ss_currentScanDesc) + table_rescan(node->ss.ss_currentScanDesc, NULL); /* release bitmaps and buffers if any */ if (node->tbmiterator) @@ -678,7 +693,9 @@ ExecEndBitmapHeapScan(BitmapHeapScanState *node) /* * close heap scan */ - table_endscan(scanDesc); + if (scanDesc) + table_endscan(scanDesc); + } /* ---------------------------------------------------------------- @@ -783,11 +800,6 @@ ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags) scanstate->ss.ss_currentRelation = currentRelation; - scanstate->ss.ss_currentScanDesc = table_beginscan_bm(currentRelation, - estate->es_snapshot, - 0, - NULL); - /* * all done. */ -- 2.40.1 --xqq4defy3uncu6k6 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v8-0002-BitmapHeapScan-set-can_skip_fetch-later.patch" ^ permalink raw reply [nested|flat] 17+ messages in thread
* [PATCH v18 01/10] BitmapHeapScan: begin scan after bitmap creation @ 2024-02-12 23:50 Melanie Plageman <[email protected]> 0 siblings, 0 replies; 17+ messages in thread From: Melanie Plageman @ 2024-02-12 23:50 UTC (permalink / raw) It makes more sense for BitmapHeapScan to scan the index, build the bitmap, and only then begin the scan on the underlying table. This is mostly a cosmetic change for now, but later commits will need to pass parameters to table_beginscan_bm() that are unavailable in ExecInitBitmapHeapScan(). Author: Melanie Plageman Reviewed-by: Tomas Vondra, Andres Freund, Heikki Linnakangas Discussion: https://postgr.es/m/CAAKRu_ZwCwWFeL_H3ia26bP2e7HiKLWt0ZmGXPVwPO6uXq0vaA%40mail.gmail.com --- src/backend/executor/nodeBitmapHeapscan.c | 27 +++++++++++++++++------ 1 file changed, 20 insertions(+), 7 deletions(-) diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c index cee7f45aabe..c8c466e3c5c 100644 --- a/src/backend/executor/nodeBitmapHeapscan.c +++ b/src/backend/executor/nodeBitmapHeapscan.c @@ -178,6 +178,21 @@ BitmapHeapNext(BitmapHeapScanState *node) } #endif /* USE_PREFETCH */ } + + /* + * If this is the first scan of the underlying table, create the table + * scan descriptor and begin the scan. + */ + if (!scan) + { + scan = table_beginscan_bm(node->ss.ss_currentRelation, + node->ss.ps.state->es_snapshot, + 0, + NULL); + + node->ss.ss_currentScanDesc = scan; + } + node->initialized = true; } @@ -601,7 +616,8 @@ ExecReScanBitmapHeapScan(BitmapHeapScanState *node) PlanState *outerPlan = outerPlanState(node); /* rescan to release any page pin */ - table_rescan(node->ss.ss_currentScanDesc, NULL); + if (node->ss.ss_currentScanDesc) + table_rescan(node->ss.ss_currentScanDesc, NULL); /* release bitmaps and buffers if any */ if (node->tbmiterator) @@ -678,7 +694,9 @@ ExecEndBitmapHeapScan(BitmapHeapScanState *node) /* * close heap scan */ - table_endscan(scanDesc); + if (scanDesc) + table_endscan(scanDesc); + } /* ---------------------------------------------------------------- @@ -783,11 +801,6 @@ ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags) scanstate->ss.ss_currentRelation = currentRelation; - scanstate->ss.ss_currentScanDesc = table_beginscan_bm(currentRelation, - estate->es_snapshot, - 0, - NULL); - /* * all done. */ -- 2.40.1 --zmcd37za4qx3kv73 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v18-0002-BitmapHeapScan-postpone-setting-can_skip_fetch.patch" ^ permalink raw reply [nested|flat] 17+ messages in thread
* [PATCH v5 01/14] BitmapHeapScan begin scan after bitmap creation @ 2024-02-12 23:50 Melanie Plageman <[email protected]> 0 siblings, 0 replies; 17+ messages in thread From: Melanie Plageman @ 2024-02-12 23:50 UTC (permalink / raw) There is no reason for a BitmapHeapScan to begin the scan of the underlying table in ExecInitBitmapHeapScan(). Instead, do so after completing the index scan and building the bitmap. ExecBitmapHeapInitializeWorker() overwrote the snapshot in the scan descriptor with the correct one provided by the parallel leader. Since ExecBitmapHeapInitializeWorker() is now called before the scan descriptor has been created, save the worker's snapshot in the BitmapHeapScanState and pass it to table_beginscan_bm(). --- src/backend/access/table/tableam.c | 11 ------ src/backend/executor/nodeBitmapHeapscan.c | 47 ++++++++++++++++++----- src/include/access/tableam.h | 10 ++--- src/include/nodes/execnodes.h | 2 + 4 files changed, 42 insertions(+), 28 deletions(-) diff --git a/src/backend/access/table/tableam.c b/src/backend/access/table/tableam.c index 6ed8cca05a1..e78d793f69c 100644 --- a/src/backend/access/table/tableam.c +++ b/src/backend/access/table/tableam.c @@ -120,17 +120,6 @@ table_beginscan_catalog(Relation relation, int nkeys, struct ScanKeyData *key) NULL, flags); } -void -table_scan_update_snapshot(TableScanDesc scan, Snapshot snapshot) -{ - Assert(IsMVCCSnapshot(snapshot)); - - RegisterSnapshot(snapshot); - scan->rs_snapshot = snapshot; - scan->rs_flags |= SO_TEMP_SNAPSHOT; -} - - /* ---------------------------------------------------------------------------- * Parallel table scan related functions. * ---------------------------------------------------------------------------- diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c index c1e81ebed63..44bf38be3c9 100644 --- a/src/backend/executor/nodeBitmapHeapscan.c +++ b/src/backend/executor/nodeBitmapHeapscan.c @@ -181,6 +181,34 @@ BitmapHeapNext(BitmapHeapScanState *node) } #endif /* USE_PREFETCH */ } + + /* + * If this is the first scan of the underlying table, create the table + * scan descriptor and begin the scan. + */ + if (!scan) + { + Snapshot snapshot = node->ss.ps.state->es_snapshot; + uint32 extra_flags = 0; + + /* + * Parallel workers must use the snapshot initialized by the + * parallel leader. + */ + if (node->worker_snapshot) + { + snapshot = node->worker_snapshot; + extra_flags |= SO_TEMP_SNAPSHOT; + } + + scan = node->ss.ss_currentScanDesc = table_beginscan_bm( + node->ss.ss_currentRelation, + snapshot, + 0, + NULL, + extra_flags); + } + node->initialized = true; } @@ -604,7 +632,8 @@ ExecReScanBitmapHeapScan(BitmapHeapScanState *node) PlanState *outerPlan = outerPlanState(node); /* rescan to release any page pin */ - table_rescan(node->ss.ss_currentScanDesc, NULL); + if (node->ss.ss_currentScanDesc) + table_rescan(node->ss.ss_currentScanDesc, NULL); /* release bitmaps and buffers if any */ if (node->tbmiterator) @@ -681,7 +710,9 @@ ExecEndBitmapHeapScan(BitmapHeapScanState *node) /* * close heap scan */ - table_endscan(scanDesc); + if (scanDesc) + table_endscan(scanDesc); + } /* ---------------------------------------------------------------- @@ -739,6 +770,7 @@ ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags) */ scanstate->can_skip_fetch = (node->scan.plan.qual == NIL && node->scan.plan.targetlist == NIL); + scanstate->worker_snapshot = NULL; /* * Miscellaneous initialization @@ -787,11 +819,6 @@ ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags) scanstate->ss.ss_currentRelation = currentRelation; - scanstate->ss.ss_currentScanDesc = table_beginscan_bm(currentRelation, - estate->es_snapshot, - 0, - NULL); - /* * all done. */ @@ -930,13 +957,13 @@ ExecBitmapHeapInitializeWorker(BitmapHeapScanState *node, ParallelWorkerContext *pwcxt) { ParallelBitmapHeapState *pstate; - Snapshot snapshot; Assert(node->ss.ps.state->es_query_dsa != NULL); pstate = shm_toc_lookup(pwcxt->toc, node->ss.ps.plan->plan_node_id, false); node->pstate = pstate; - snapshot = RestoreSnapshot(pstate->phs_snapshot_data); - table_scan_update_snapshot(node->ss.ss_currentScanDesc, snapshot); + node->worker_snapshot = RestoreSnapshot(pstate->phs_snapshot_data); + Assert(IsMVCCSnapshot(node->worker_snapshot)); + RegisterSnapshot(node->worker_snapshot); } diff --git a/src/include/access/tableam.h b/src/include/access/tableam.h index 5f8474871d2..5375dd7150f 100644 --- a/src/include/access/tableam.h +++ b/src/include/access/tableam.h @@ -944,9 +944,10 @@ table_beginscan_strat(Relation rel, Snapshot snapshot, */ static inline TableScanDesc table_beginscan_bm(Relation rel, Snapshot snapshot, - int nkeys, struct ScanKeyData *key) + int nkeys, struct ScanKeyData *key, + uint32 extra_flags) { - uint32 flags = SO_TYPE_BITMAPSCAN | SO_ALLOW_PAGEMODE; + uint32 flags = SO_TYPE_BITMAPSCAN | SO_ALLOW_PAGEMODE | extra_flags; return rel->rd_tableam->scan_begin(rel, snapshot, nkeys, key, NULL, flags); } @@ -1038,11 +1039,6 @@ table_rescan_set_params(TableScanDesc scan, struct ScanKeyData *key, allow_pagemode); } -/* - * Update snapshot used by the scan. - */ -extern void table_scan_update_snapshot(TableScanDesc scan, Snapshot snapshot); - /* * Return next tuple from `scan`, store in slot. */ diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h index 444a5f0fd57..00c75fb10e2 100644 --- a/src/include/nodes/execnodes.h +++ b/src/include/nodes/execnodes.h @@ -1726,6 +1726,7 @@ typedef struct ParallelBitmapHeapState * shared_tbmiterator shared iterator * shared_prefetch_iterator shared iterator for prefetching * pstate shared state for parallel bitmap scan + * worker_snapshot snapshot for parallel worker * ---------------- */ typedef struct BitmapHeapScanState @@ -1750,6 +1751,7 @@ typedef struct BitmapHeapScanState TBMSharedIterator *shared_tbmiterator; TBMSharedIterator *shared_prefetch_iterator; ParallelBitmapHeapState *pstate; + Snapshot worker_snapshot; } BitmapHeapScanState; /* ---------------- -- 2.37.2 --6kjpcnqyi64ibp5i Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0002-BitmapHeapScan-set-can_skip_fetch-later.patch" ^ permalink raw reply [nested|flat] 17+ messages in thread
* [PATCH v16 01/18] BitmapHeapScan begin scan after bitmap creation @ 2024-02-12 23:50 Melanie Plageman <[email protected]> 0 siblings, 0 replies; 17+ messages in thread From: Melanie Plageman @ 2024-02-12 23:50 UTC (permalink / raw) It makes more sense for BitmapHeapScan to scan the index, build the bitmap, and then begin the scan on the underlying table. This is primarily a cosmetic change for now, but later commits will pass parameters to table_beginscan_bm() that are unavailable in ExecInitBitmapHeapScan(). Author: Melanie Plageman Reviewed-by: Andres Freund, Heikki Linnakangas, Tomas Vondra Discussion: https://postgr.es/m/CAAKRu_ZwCwWFeL_H3ia26bP2e7HiKLWt0ZmGXPVwPO6uXq0vaA%40mail.gmail.com --- src/backend/executor/nodeBitmapHeapscan.c | 27 +++++++++++++++++------ 1 file changed, 20 insertions(+), 7 deletions(-) diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c index cee7f45aab..c8c466e3c5 100644 --- a/src/backend/executor/nodeBitmapHeapscan.c +++ b/src/backend/executor/nodeBitmapHeapscan.c @@ -178,6 +178,21 @@ BitmapHeapNext(BitmapHeapScanState *node) } #endif /* USE_PREFETCH */ } + + /* + * If this is the first scan of the underlying table, create the table + * scan descriptor and begin the scan. + */ + if (!scan) + { + scan = table_beginscan_bm(node->ss.ss_currentRelation, + node->ss.ps.state->es_snapshot, + 0, + NULL); + + node->ss.ss_currentScanDesc = scan; + } + node->initialized = true; } @@ -601,7 +616,8 @@ ExecReScanBitmapHeapScan(BitmapHeapScanState *node) PlanState *outerPlan = outerPlanState(node); /* rescan to release any page pin */ - table_rescan(node->ss.ss_currentScanDesc, NULL); + if (node->ss.ss_currentScanDesc) + table_rescan(node->ss.ss_currentScanDesc, NULL); /* release bitmaps and buffers if any */ if (node->tbmiterator) @@ -678,7 +694,9 @@ ExecEndBitmapHeapScan(BitmapHeapScanState *node) /* * close heap scan */ - table_endscan(scanDesc); + if (scanDesc) + table_endscan(scanDesc); + } /* ---------------------------------------------------------------- @@ -783,11 +801,6 @@ ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags) scanstate->ss.ss_currentRelation = currentRelation; - scanstate->ss.ss_currentScanDesc = table_beginscan_bm(currentRelation, - estate->es_snapshot, - 0, - NULL); - /* * all done. */ -- 2.40.1 --e3xl7h75mzefinno Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v16-0002-BitmapHeapScan-set-can_skip_fetch-later.patch" ^ permalink raw reply [nested|flat] 17+ messages in thread
* [PATCH v9 01/17] BitmapHeapScan begin scan after bitmap creation @ 2024-02-12 23:50 Melanie Plageman <[email protected]> 0 siblings, 0 replies; 17+ messages in thread From: Melanie Plageman @ 2024-02-12 23:50 UTC (permalink / raw) There is no reason for a BitmapHeapScan to begin the scan of the underlying table in ExecInitBitmapHeapScan(). Instead, do so after completing the index scan and building the bitmap. --- src/backend/access/table/tableam.c | 1 - src/backend/executor/nodeBitmapHeapscan.c | 26 +++++++++++++++++------ 2 files changed, 19 insertions(+), 8 deletions(-) diff --git a/src/backend/access/table/tableam.c b/src/backend/access/table/tableam.c index e57a0b7ea3..e78d793f69 100644 --- a/src/backend/access/table/tableam.c +++ b/src/backend/access/table/tableam.c @@ -120,7 +120,6 @@ table_beginscan_catalog(Relation relation, int nkeys, struct ScanKeyData *key) NULL, flags); } - /* ---------------------------------------------------------------------------- * Parallel table scan related functions. * ---------------------------------------------------------------------------- diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c index cee7f45aab..93fdcd226b 100644 --- a/src/backend/executor/nodeBitmapHeapscan.c +++ b/src/backend/executor/nodeBitmapHeapscan.c @@ -178,6 +178,20 @@ BitmapHeapNext(BitmapHeapScanState *node) } #endif /* USE_PREFETCH */ } + + /* + * If this is the first scan of the underlying table, create the table + * scan descriptor and begin the scan. + */ + if (!scan) + { + scan = node->ss.ss_currentScanDesc = table_beginscan_bm( + node->ss.ss_currentRelation, + node->ss.ps.state->es_snapshot, + 0, + NULL); + } + node->initialized = true; } @@ -601,7 +615,8 @@ ExecReScanBitmapHeapScan(BitmapHeapScanState *node) PlanState *outerPlan = outerPlanState(node); /* rescan to release any page pin */ - table_rescan(node->ss.ss_currentScanDesc, NULL); + if (node->ss.ss_currentScanDesc) + table_rescan(node->ss.ss_currentScanDesc, NULL); /* release bitmaps and buffers if any */ if (node->tbmiterator) @@ -678,7 +693,9 @@ ExecEndBitmapHeapScan(BitmapHeapScanState *node) /* * close heap scan */ - table_endscan(scanDesc); + if (scanDesc) + table_endscan(scanDesc); + } /* ---------------------------------------------------------------- @@ -783,11 +800,6 @@ ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags) scanstate->ss.ss_currentRelation = currentRelation; - scanstate->ss.ss_currentScanDesc = table_beginscan_bm(currentRelation, - estate->es_snapshot, - 0, - NULL); - /* * all done. */ -- 2.40.1 --7mdtsjmrzitrgzgx Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v9-0002-BitmapHeapScan-set-can_skip_fetch-later.patch" ^ permalink raw reply [nested|flat] 17+ messages in thread
* [PATCH v10 01/17] BitmapHeapScan begin scan after bitmap creation @ 2024-02-12 23:50 Melanie Plageman <[email protected]> 0 siblings, 0 replies; 17+ messages in thread From: Melanie Plageman @ 2024-02-12 23:50 UTC (permalink / raw) There is no reason for a BitmapHeapScan to begin the scan of the underlying table in ExecInitBitmapHeapScan(). Instead, do so after completing the index scan and building the bitmap. --- src/backend/access/table/tableam.c | 1 - src/backend/executor/nodeBitmapHeapscan.c | 26 +++++++++++++++++------ 2 files changed, 19 insertions(+), 8 deletions(-) diff --git a/src/backend/access/table/tableam.c b/src/backend/access/table/tableam.c index e57a0b7ea3..e78d793f69 100644 --- a/src/backend/access/table/tableam.c +++ b/src/backend/access/table/tableam.c @@ -120,7 +120,6 @@ table_beginscan_catalog(Relation relation, int nkeys, struct ScanKeyData *key) NULL, flags); } - /* ---------------------------------------------------------------------------- * Parallel table scan related functions. * ---------------------------------------------------------------------------- diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c index cee7f45aab..93fdcd226b 100644 --- a/src/backend/executor/nodeBitmapHeapscan.c +++ b/src/backend/executor/nodeBitmapHeapscan.c @@ -178,6 +178,20 @@ BitmapHeapNext(BitmapHeapScanState *node) } #endif /* USE_PREFETCH */ } + + /* + * If this is the first scan of the underlying table, create the table + * scan descriptor and begin the scan. + */ + if (!scan) + { + scan = node->ss.ss_currentScanDesc = table_beginscan_bm( + node->ss.ss_currentRelation, + node->ss.ps.state->es_snapshot, + 0, + NULL); + } + node->initialized = true; } @@ -601,7 +615,8 @@ ExecReScanBitmapHeapScan(BitmapHeapScanState *node) PlanState *outerPlan = outerPlanState(node); /* rescan to release any page pin */ - table_rescan(node->ss.ss_currentScanDesc, NULL); + if (node->ss.ss_currentScanDesc) + table_rescan(node->ss.ss_currentScanDesc, NULL); /* release bitmaps and buffers if any */ if (node->tbmiterator) @@ -678,7 +693,9 @@ ExecEndBitmapHeapScan(BitmapHeapScanState *node) /* * close heap scan */ - table_endscan(scanDesc); + if (scanDesc) + table_endscan(scanDesc); + } /* ---------------------------------------------------------------- @@ -783,11 +800,6 @@ ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags) scanstate->ss.ss_currentRelation = currentRelation; - scanstate->ss.ss_currentScanDesc = table_beginscan_bm(currentRelation, - estate->es_snapshot, - 0, - NULL); - /* * all done. */ -- 2.40.1 --3o7pc6dfau5a5hry Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v10-0002-BitmapHeapScan-set-can_skip_fetch-later.patch" ^ permalink raw reply [nested|flat] 17+ messages in thread
* [PATCH v12 01/17] BitmapHeapScan begin scan after bitmap creation @ 2024-02-12 23:50 Melanie Plageman <[email protected]> 0 siblings, 0 replies; 17+ messages in thread From: Melanie Plageman @ 2024-02-12 23:50 UTC (permalink / raw) There is no reason for a BitmapHeapScan to begin the scan of the underlying table in ExecInitBitmapHeapScan(). Instead, do so after completing the index scan and building the bitmap. --- src/backend/access/table/tableam.c | 1 - src/backend/executor/nodeBitmapHeapscan.c | 26 +++++++++++++++++------ 2 files changed, 19 insertions(+), 8 deletions(-) diff --git a/src/backend/access/table/tableam.c b/src/backend/access/table/tableam.c index 805d222cebc..b0f61c65f36 100644 --- a/src/backend/access/table/tableam.c +++ b/src/backend/access/table/tableam.c @@ -120,7 +120,6 @@ table_beginscan_catalog(Relation relation, int nkeys, struct ScanKeyData *key) NULL, flags); } - /* ---------------------------------------------------------------------------- * Parallel table scan related functions. * ---------------------------------------------------------------------------- diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c index cee7f45aabe..93fdcd226bf 100644 --- a/src/backend/executor/nodeBitmapHeapscan.c +++ b/src/backend/executor/nodeBitmapHeapscan.c @@ -178,6 +178,20 @@ BitmapHeapNext(BitmapHeapScanState *node) } #endif /* USE_PREFETCH */ } + + /* + * If this is the first scan of the underlying table, create the table + * scan descriptor and begin the scan. + */ + if (!scan) + { + scan = node->ss.ss_currentScanDesc = table_beginscan_bm( + node->ss.ss_currentRelation, + node->ss.ps.state->es_snapshot, + 0, + NULL); + } + node->initialized = true; } @@ -601,7 +615,8 @@ ExecReScanBitmapHeapScan(BitmapHeapScanState *node) PlanState *outerPlan = outerPlanState(node); /* rescan to release any page pin */ - table_rescan(node->ss.ss_currentScanDesc, NULL); + if (node->ss.ss_currentScanDesc) + table_rescan(node->ss.ss_currentScanDesc, NULL); /* release bitmaps and buffers if any */ if (node->tbmiterator) @@ -678,7 +693,9 @@ ExecEndBitmapHeapScan(BitmapHeapScanState *node) /* * close heap scan */ - table_endscan(scanDesc); + if (scanDesc) + table_endscan(scanDesc); + } /* ---------------------------------------------------------------- @@ -783,11 +800,6 @@ ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags) scanstate->ss.ss_currentRelation = currentRelation; - scanstate->ss.ss_currentScanDesc = table_beginscan_bm(currentRelation, - estate->es_snapshot, - 0, - NULL); - /* * all done. */ -- 2.40.1 --6jpz2j246qmht4bt Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v12-0002-BitmapHeapScan-set-can_skip_fetch-later.patch" ^ permalink raw reply [nested|flat] 17+ messages in thread
* [PATCH v11 01/17] BitmapHeapScan begin scan after bitmap creation @ 2024-02-12 23:50 Melanie Plageman <[email protected]> 0 siblings, 0 replies; 17+ messages in thread From: Melanie Plageman @ 2024-02-12 23:50 UTC (permalink / raw) There is no reason for a BitmapHeapScan to begin the scan of the underlying table in ExecInitBitmapHeapScan(). Instead, do so after completing the index scan and building the bitmap. --- src/backend/access/table/tableam.c | 1 - src/backend/executor/nodeBitmapHeapscan.c | 26 +++++++++++++++++------ 2 files changed, 19 insertions(+), 8 deletions(-) diff --git a/src/backend/access/table/tableam.c b/src/backend/access/table/tableam.c index 8d3675be95..a254e3175b 100644 --- a/src/backend/access/table/tableam.c +++ b/src/backend/access/table/tableam.c @@ -120,7 +120,6 @@ table_beginscan_catalog(Relation relation, int nkeys, struct ScanKeyData *key) NULL, flags); } - /* ---------------------------------------------------------------------------- * Parallel table scan related functions. * ---------------------------------------------------------------------------- diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c index cee7f45aab..93fdcd226b 100644 --- a/src/backend/executor/nodeBitmapHeapscan.c +++ b/src/backend/executor/nodeBitmapHeapscan.c @@ -178,6 +178,20 @@ BitmapHeapNext(BitmapHeapScanState *node) } #endif /* USE_PREFETCH */ } + + /* + * If this is the first scan of the underlying table, create the table + * scan descriptor and begin the scan. + */ + if (!scan) + { + scan = node->ss.ss_currentScanDesc = table_beginscan_bm( + node->ss.ss_currentRelation, + node->ss.ps.state->es_snapshot, + 0, + NULL); + } + node->initialized = true; } @@ -601,7 +615,8 @@ ExecReScanBitmapHeapScan(BitmapHeapScanState *node) PlanState *outerPlan = outerPlanState(node); /* rescan to release any page pin */ - table_rescan(node->ss.ss_currentScanDesc, NULL); + if (node->ss.ss_currentScanDesc) + table_rescan(node->ss.ss_currentScanDesc, NULL); /* release bitmaps and buffers if any */ if (node->tbmiterator) @@ -678,7 +693,9 @@ ExecEndBitmapHeapScan(BitmapHeapScanState *node) /* * close heap scan */ - table_endscan(scanDesc); + if (scanDesc) + table_endscan(scanDesc); + } /* ---------------------------------------------------------------- @@ -783,11 +800,6 @@ ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags) scanstate->ss.ss_currentRelation = currentRelation; - scanstate->ss.ss_currentScanDesc = table_beginscan_bm(currentRelation, - estate->es_snapshot, - 0, - NULL); - /* * all done. */ -- 2.40.1 --owzzsiozz6hgpp7e Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v11-0002-BitmapHeapScan-set-can_skip_fetch-later.patch" ^ permalink raw reply [nested|flat] 17+ messages in thread
* [PATCH v3 01/13] BitmapHeapScan begin scan after bitmap creation @ 2024-02-12 23:50 Melanie Plageman <[email protected]> 0 siblings, 0 replies; 17+ messages in thread From: Melanie Plageman @ 2024-02-12 23:50 UTC (permalink / raw) There is no reason for a BitmapHeapScan to begin the scan of the underlying table in ExecInitBitmapHeapScan(). Instead, do so after completing the index scan and building the bitmap. ExecBitmapHeapInitializeWorker() overwrote the snapshot in the scan descriptor with the correct one provided by the parallel leader. Since ExecBitmapHeapInitializeWorker() is now called before the scan descriptor has been created, save the worker's snapshot in the BitmapHeapScanState and pass it to table_beginscan_bm(). --- src/backend/access/table/tableam.c | 11 ------ src/backend/executor/nodeBitmapHeapscan.c | 47 ++++++++++++++++++----- src/include/access/tableam.h | 10 ++--- src/include/nodes/execnodes.h | 2 + 4 files changed, 42 insertions(+), 28 deletions(-) diff --git a/src/backend/access/table/tableam.c b/src/backend/access/table/tableam.c index 6ed8cca05a1..e78d793f69c 100644 --- a/src/backend/access/table/tableam.c +++ b/src/backend/access/table/tableam.c @@ -120,17 +120,6 @@ table_beginscan_catalog(Relation relation, int nkeys, struct ScanKeyData *key) NULL, flags); } -void -table_scan_update_snapshot(TableScanDesc scan, Snapshot snapshot) -{ - Assert(IsMVCCSnapshot(snapshot)); - - RegisterSnapshot(snapshot); - scan->rs_snapshot = snapshot; - scan->rs_flags |= SO_TEMP_SNAPSHOT; -} - - /* ---------------------------------------------------------------------------- * Parallel table scan related functions. * ---------------------------------------------------------------------------- diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c index c1e81ebed63..44bf38be3c9 100644 --- a/src/backend/executor/nodeBitmapHeapscan.c +++ b/src/backend/executor/nodeBitmapHeapscan.c @@ -181,6 +181,34 @@ BitmapHeapNext(BitmapHeapScanState *node) } #endif /* USE_PREFETCH */ } + + /* + * If this is the first scan of the underlying table, create the table + * scan descriptor and begin the scan. + */ + if (!scan) + { + Snapshot snapshot = node->ss.ps.state->es_snapshot; + uint32 extra_flags = 0; + + /* + * Parallel workers must use the snapshot initialized by the + * parallel leader. + */ + if (node->worker_snapshot) + { + snapshot = node->worker_snapshot; + extra_flags |= SO_TEMP_SNAPSHOT; + } + + scan = node->ss.ss_currentScanDesc = table_beginscan_bm( + node->ss.ss_currentRelation, + snapshot, + 0, + NULL, + extra_flags); + } + node->initialized = true; } @@ -604,7 +632,8 @@ ExecReScanBitmapHeapScan(BitmapHeapScanState *node) PlanState *outerPlan = outerPlanState(node); /* rescan to release any page pin */ - table_rescan(node->ss.ss_currentScanDesc, NULL); + if (node->ss.ss_currentScanDesc) + table_rescan(node->ss.ss_currentScanDesc, NULL); /* release bitmaps and buffers if any */ if (node->tbmiterator) @@ -681,7 +710,9 @@ ExecEndBitmapHeapScan(BitmapHeapScanState *node) /* * close heap scan */ - table_endscan(scanDesc); + if (scanDesc) + table_endscan(scanDesc); + } /* ---------------------------------------------------------------- @@ -739,6 +770,7 @@ ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags) */ scanstate->can_skip_fetch = (node->scan.plan.qual == NIL && node->scan.plan.targetlist == NIL); + scanstate->worker_snapshot = NULL; /* * Miscellaneous initialization @@ -787,11 +819,6 @@ ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags) scanstate->ss.ss_currentRelation = currentRelation; - scanstate->ss.ss_currentScanDesc = table_beginscan_bm(currentRelation, - estate->es_snapshot, - 0, - NULL); - /* * all done. */ @@ -930,13 +957,13 @@ ExecBitmapHeapInitializeWorker(BitmapHeapScanState *node, ParallelWorkerContext *pwcxt) { ParallelBitmapHeapState *pstate; - Snapshot snapshot; Assert(node->ss.ps.state->es_query_dsa != NULL); pstate = shm_toc_lookup(pwcxt->toc, node->ss.ps.plan->plan_node_id, false); node->pstate = pstate; - snapshot = RestoreSnapshot(pstate->phs_snapshot_data); - table_scan_update_snapshot(node->ss.ss_currentScanDesc, snapshot); + node->worker_snapshot = RestoreSnapshot(pstate->phs_snapshot_data); + Assert(IsMVCCSnapshot(node->worker_snapshot)); + RegisterSnapshot(node->worker_snapshot); } diff --git a/src/include/access/tableam.h b/src/include/access/tableam.h index 5f8474871d2..5375dd7150f 100644 --- a/src/include/access/tableam.h +++ b/src/include/access/tableam.h @@ -944,9 +944,10 @@ table_beginscan_strat(Relation rel, Snapshot snapshot, */ static inline TableScanDesc table_beginscan_bm(Relation rel, Snapshot snapshot, - int nkeys, struct ScanKeyData *key) + int nkeys, struct ScanKeyData *key, + uint32 extra_flags) { - uint32 flags = SO_TYPE_BITMAPSCAN | SO_ALLOW_PAGEMODE; + uint32 flags = SO_TYPE_BITMAPSCAN | SO_ALLOW_PAGEMODE | extra_flags; return rel->rd_tableam->scan_begin(rel, snapshot, nkeys, key, NULL, flags); } @@ -1038,11 +1039,6 @@ table_rescan_set_params(TableScanDesc scan, struct ScanKeyData *key, allow_pagemode); } -/* - * Update snapshot used by the scan. - */ -extern void table_scan_update_snapshot(TableScanDesc scan, Snapshot snapshot); - /* * Return next tuple from `scan`, store in slot. */ diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h index 444a5f0fd57..00c75fb10e2 100644 --- a/src/include/nodes/execnodes.h +++ b/src/include/nodes/execnodes.h @@ -1726,6 +1726,7 @@ typedef struct ParallelBitmapHeapState * shared_tbmiterator shared iterator * shared_prefetch_iterator shared iterator for prefetching * pstate shared state for parallel bitmap scan + * worker_snapshot snapshot for parallel worker * ---------------- */ typedef struct BitmapHeapScanState @@ -1750,6 +1751,7 @@ typedef struct BitmapHeapScanState TBMSharedIterator *shared_tbmiterator; TBMSharedIterator *shared_prefetch_iterator; ParallelBitmapHeapState *pstate; + Snapshot worker_snapshot; } BitmapHeapScanState; /* ---------------- -- 2.37.2 --fa5b4qdlc6zixc7z Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0002-BitmapHeapScan-set-can_skip_fetch-later.patch" ^ permalink raw reply [nested|flat] 17+ messages in thread
* [PATCH v4 01/14] BitmapHeapScan begin scan after bitmap creation @ 2024-02-12 23:50 Melanie Plageman <[email protected]> 0 siblings, 0 replies; 17+ messages in thread From: Melanie Plageman @ 2024-02-12 23:50 UTC (permalink / raw) There is no reason for a BitmapHeapScan to begin the scan of the underlying table in ExecInitBitmapHeapScan(). Instead, do so after completing the index scan and building the bitmap. ExecBitmapHeapInitializeWorker() overwrote the snapshot in the scan descriptor with the correct one provided by the parallel leader. Since ExecBitmapHeapInitializeWorker() is now called before the scan descriptor has been created, save the worker's snapshot in the BitmapHeapScanState and pass it to table_beginscan_bm(). --- src/backend/access/table/tableam.c | 11 ------ src/backend/executor/nodeBitmapHeapscan.c | 47 ++++++++++++++++++----- src/include/access/tableam.h | 10 ++--- src/include/nodes/execnodes.h | 2 + 4 files changed, 42 insertions(+), 28 deletions(-) diff --git a/src/backend/access/table/tableam.c b/src/backend/access/table/tableam.c index 6ed8cca05a1..e78d793f69c 100644 --- a/src/backend/access/table/tableam.c +++ b/src/backend/access/table/tableam.c @@ -120,17 +120,6 @@ table_beginscan_catalog(Relation relation, int nkeys, struct ScanKeyData *key) NULL, flags); } -void -table_scan_update_snapshot(TableScanDesc scan, Snapshot snapshot) -{ - Assert(IsMVCCSnapshot(snapshot)); - - RegisterSnapshot(snapshot); - scan->rs_snapshot = snapshot; - scan->rs_flags |= SO_TEMP_SNAPSHOT; -} - - /* ---------------------------------------------------------------------------- * Parallel table scan related functions. * ---------------------------------------------------------------------------- diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c index c1e81ebed63..44bf38be3c9 100644 --- a/src/backend/executor/nodeBitmapHeapscan.c +++ b/src/backend/executor/nodeBitmapHeapscan.c @@ -181,6 +181,34 @@ BitmapHeapNext(BitmapHeapScanState *node) } #endif /* USE_PREFETCH */ } + + /* + * If this is the first scan of the underlying table, create the table + * scan descriptor and begin the scan. + */ + if (!scan) + { + Snapshot snapshot = node->ss.ps.state->es_snapshot; + uint32 extra_flags = 0; + + /* + * Parallel workers must use the snapshot initialized by the + * parallel leader. + */ + if (node->worker_snapshot) + { + snapshot = node->worker_snapshot; + extra_flags |= SO_TEMP_SNAPSHOT; + } + + scan = node->ss.ss_currentScanDesc = table_beginscan_bm( + node->ss.ss_currentRelation, + snapshot, + 0, + NULL, + extra_flags); + } + node->initialized = true; } @@ -604,7 +632,8 @@ ExecReScanBitmapHeapScan(BitmapHeapScanState *node) PlanState *outerPlan = outerPlanState(node); /* rescan to release any page pin */ - table_rescan(node->ss.ss_currentScanDesc, NULL); + if (node->ss.ss_currentScanDesc) + table_rescan(node->ss.ss_currentScanDesc, NULL); /* release bitmaps and buffers if any */ if (node->tbmiterator) @@ -681,7 +710,9 @@ ExecEndBitmapHeapScan(BitmapHeapScanState *node) /* * close heap scan */ - table_endscan(scanDesc); + if (scanDesc) + table_endscan(scanDesc); + } /* ---------------------------------------------------------------- @@ -739,6 +770,7 @@ ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags) */ scanstate->can_skip_fetch = (node->scan.plan.qual == NIL && node->scan.plan.targetlist == NIL); + scanstate->worker_snapshot = NULL; /* * Miscellaneous initialization @@ -787,11 +819,6 @@ ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags) scanstate->ss.ss_currentRelation = currentRelation; - scanstate->ss.ss_currentScanDesc = table_beginscan_bm(currentRelation, - estate->es_snapshot, - 0, - NULL); - /* * all done. */ @@ -930,13 +957,13 @@ ExecBitmapHeapInitializeWorker(BitmapHeapScanState *node, ParallelWorkerContext *pwcxt) { ParallelBitmapHeapState *pstate; - Snapshot snapshot; Assert(node->ss.ps.state->es_query_dsa != NULL); pstate = shm_toc_lookup(pwcxt->toc, node->ss.ps.plan->plan_node_id, false); node->pstate = pstate; - snapshot = RestoreSnapshot(pstate->phs_snapshot_data); - table_scan_update_snapshot(node->ss.ss_currentScanDesc, snapshot); + node->worker_snapshot = RestoreSnapshot(pstate->phs_snapshot_data); + Assert(IsMVCCSnapshot(node->worker_snapshot)); + RegisterSnapshot(node->worker_snapshot); } diff --git a/src/include/access/tableam.h b/src/include/access/tableam.h index 5f8474871d2..5375dd7150f 100644 --- a/src/include/access/tableam.h +++ b/src/include/access/tableam.h @@ -944,9 +944,10 @@ table_beginscan_strat(Relation rel, Snapshot snapshot, */ static inline TableScanDesc table_beginscan_bm(Relation rel, Snapshot snapshot, - int nkeys, struct ScanKeyData *key) + int nkeys, struct ScanKeyData *key, + uint32 extra_flags) { - uint32 flags = SO_TYPE_BITMAPSCAN | SO_ALLOW_PAGEMODE; + uint32 flags = SO_TYPE_BITMAPSCAN | SO_ALLOW_PAGEMODE | extra_flags; return rel->rd_tableam->scan_begin(rel, snapshot, nkeys, key, NULL, flags); } @@ -1038,11 +1039,6 @@ table_rescan_set_params(TableScanDesc scan, struct ScanKeyData *key, allow_pagemode); } -/* - * Update snapshot used by the scan. - */ -extern void table_scan_update_snapshot(TableScanDesc scan, Snapshot snapshot); - /* * Return next tuple from `scan`, store in slot. */ diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h index 444a5f0fd57..00c75fb10e2 100644 --- a/src/include/nodes/execnodes.h +++ b/src/include/nodes/execnodes.h @@ -1726,6 +1726,7 @@ typedef struct ParallelBitmapHeapState * shared_tbmiterator shared iterator * shared_prefetch_iterator shared iterator for prefetching * pstate shared state for parallel bitmap scan + * worker_snapshot snapshot for parallel worker * ---------------- */ typedef struct BitmapHeapScanState @@ -1750,6 +1751,7 @@ typedef struct BitmapHeapScanState TBMSharedIterator *shared_tbmiterator; TBMSharedIterator *shared_prefetch_iterator; ParallelBitmapHeapState *pstate; + Snapshot worker_snapshot; } BitmapHeapScanState; /* ---------------- -- 2.37.2 --5aaqsqqhbq27q3qo Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0002-BitmapHeapScan-set-can_skip_fetch-later.patch" ^ permalink raw reply [nested|flat] 17+ messages in thread
* [PATCH v17 1/9] BitmapHeapScan: begin scan after bitmap creation @ 2024-02-12 23:50 Melanie Plageman <[email protected]> 0 siblings, 0 replies; 17+ messages in thread From: Melanie Plageman @ 2024-02-12 23:50 UTC (permalink / raw) It makes more sense for BitmapHeapScan to scan the index, build the bitmap, and only then begin the scan on the underlying table. This is mostly a cosmetic change for now, but later commits will need to pass parameters to table_beginscan_bm() that are unavailable in ExecInitBitmapHeapScan(). Author: Melanie Plageman Reviewed-by: Tomas Vondra, Andres Freund, Heikki Linnakangas Discussion: https://postgr.es/m/CAAKRu_ZwCwWFeL_H3ia26bP2e7HiKLWt0ZmGXPVwPO6uXq0vaA%40mail.gmail.com --- src/backend/executor/nodeBitmapHeapscan.c | 27 +++++++++++++++++------ 1 file changed, 20 insertions(+), 7 deletions(-) diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c index cee7f45aabe..c8c466e3c5c 100644 --- a/src/backend/executor/nodeBitmapHeapscan.c +++ b/src/backend/executor/nodeBitmapHeapscan.c @@ -178,6 +178,21 @@ BitmapHeapNext(BitmapHeapScanState *node) } #endif /* USE_PREFETCH */ } + + /* + * If this is the first scan of the underlying table, create the table + * scan descriptor and begin the scan. + */ + if (!scan) + { + scan = table_beginscan_bm(node->ss.ss_currentRelation, + node->ss.ps.state->es_snapshot, + 0, + NULL); + + node->ss.ss_currentScanDesc = scan; + } + node->initialized = true; } @@ -601,7 +616,8 @@ ExecReScanBitmapHeapScan(BitmapHeapScanState *node) PlanState *outerPlan = outerPlanState(node); /* rescan to release any page pin */ - table_rescan(node->ss.ss_currentScanDesc, NULL); + if (node->ss.ss_currentScanDesc) + table_rescan(node->ss.ss_currentScanDesc, NULL); /* release bitmaps and buffers if any */ if (node->tbmiterator) @@ -678,7 +694,9 @@ ExecEndBitmapHeapScan(BitmapHeapScanState *node) /* * close heap scan */ - table_endscan(scanDesc); + if (scanDesc) + table_endscan(scanDesc); + } /* ---------------------------------------------------------------- @@ -783,11 +801,6 @@ ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags) scanstate->ss.ss_currentRelation = currentRelation; - scanstate->ss.ss_currentScanDesc = table_beginscan_bm(currentRelation, - estate->es_snapshot, - 0, - NULL); - /* * all done. */ -- 2.40.1 --etwsg7gfkf6ny266 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v17-0002-BitmapHeapScan-postpone-setting-can_skip_fetch.patch" ^ permalink raw reply [nested|flat] 17+ messages in thread
end of thread, other threads:[~2024-02-12 23:50 UTC | newest] Thread overview: 17+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2021-01-10 19:30 [PATCH] Set PD_ALL_VISIBLE and visibility map bits in COPY FREEZE Tomas Vondra <[email protected]> 2024-02-12 23:50 [PATCH v15 01/13] BitmapHeapScan begin scan after bitmap creation Melanie Plageman <[email protected]> 2024-02-12 23:50 [PATCH v7 01/13] BitmapHeapScan begin scan after bitmap creation Melanie Plageman <[email protected]> 2024-02-12 23:50 [PATCH v13 01/16] BitmapHeapScan begin scan after bitmap creation Melanie Plageman <[email protected]> 2024-02-12 23:50 [PATCH v19 01/21] BitmapHeapScan: begin scan after bitmap creation Melanie Plageman <[email protected]> 2024-02-12 23:50 [PATCH v6 01/14] BitmapHeapScan begin scan after bitmap creation Melanie Plageman <[email protected]> 2024-02-12 23:50 [PATCH v8 01/17] BitmapHeapScan begin scan after bitmap creation Melanie Plageman <[email protected]> 2024-02-12 23:50 [PATCH v18 01/10] BitmapHeapScan: begin scan after bitmap creation Melanie Plageman <[email protected]> 2024-02-12 23:50 [PATCH v5 01/14] BitmapHeapScan begin scan after bitmap creation Melanie Plageman <[email protected]> 2024-02-12 23:50 [PATCH v16 01/18] BitmapHeapScan begin scan after bitmap creation Melanie Plageman <[email protected]> 2024-02-12 23:50 [PATCH v9 01/17] BitmapHeapScan begin scan after bitmap creation Melanie Plageman <[email protected]> 2024-02-12 23:50 [PATCH v10 01/17] BitmapHeapScan begin scan after bitmap creation Melanie Plageman <[email protected]> 2024-02-12 23:50 [PATCH v12 01/17] BitmapHeapScan begin scan after bitmap creation Melanie Plageman <[email protected]> 2024-02-12 23:50 [PATCH v11 01/17] BitmapHeapScan begin scan after bitmap creation Melanie Plageman <[email protected]> 2024-02-12 23:50 [PATCH v3 01/13] BitmapHeapScan begin scan after bitmap creation Melanie Plageman <[email protected]> 2024-02-12 23:50 [PATCH v4 01/14] BitmapHeapScan begin scan after bitmap creation Melanie Plageman <[email protected]> 2024-02-12 23:50 [PATCH v17 1/9] BitmapHeapScan: begin scan after bitmap creation Melanie Plageman <[email protected]>
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