From 94f7f2fe6b6b7fdcbe4d60a157d87e607ef70dc0 Mon Sep 17 00:00:00 2001 From: Melanie Plageman Date: Tue, 19 Mar 2024 18:50:33 -0400 Subject: [PATCH v4 14/19] Vacuum second pass emits XLOG_HEAP2_PRUNE record Remove the XLOG_HEAP2_VACUUM record and update vacuum's second pass to emit a XLOG_HEAP2_PRUNE record. This temporarily wastes some space but a future commit will streamline xl_heap_prune and ensure that no unused members are included in the WAL record. --- src/backend/access/heap/heapam.c | 94 ++++-------------------- src/backend/access/heap/pruneheap.c | 67 ++++++++++------- src/backend/access/heap/vacuumlazy.c | 12 ++- src/backend/access/rmgrdesc/heapdesc.c | 20 ----- src/backend/replication/logical/decode.c | 1 - src/include/access/heapam.h | 2 +- src/include/access/heapam_xlog.h | 33 +++++---- 7 files changed, 85 insertions(+), 144 deletions(-) diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c index 532868039d5..16bab55ba02 100644 --- a/src/backend/access/heap/heapam.c +++ b/src/backend/access/heap/heapam.c @@ -8717,23 +8717,34 @@ heap_xlog_prune(XLogReaderState *record) BlockNumber blkno; XLogRedoAction action; bool get_cleanup_lock; + bool lp_truncate_only; XLogRecGetBlockTag(record, 0, &rlocator, NULL, &blkno); + lp_truncate_only = xlrec->flags & XLHP_LP_TRUNCATE_ONLY; + /* * If there are dead, redirected, or unused items set unused by * heap_page_prune_and_freeze(), heap_page_prune_execute() will call * PageRepairFragementation() which expects a full cleanup lock. */ get_cleanup_lock = xlrec->nredirected > 0 || - xlrec->ndead > 0 || xlrec->nunused > 0; + xlrec->ndead > 0 || + (xlrec->nunused > 0 && !lp_truncate_only); + + if (lp_truncate_only) + { + Assert(xlrec->nredirected == 0); + Assert(xlrec->ndead == 0); + Assert(xlrec->nunused > 0); + } /* * We are either about to remove tuples or freeze them. In Hot Standby * mode, ensure that there's no queries running for which any removed * tuples are still visible or which consider the frozen xids as running. */ - if (InHotStandby) + if (xlrec->flags & XLHP_HAS_CONFLICT_HORIZON && InHotStandby) ResolveRecoveryConflictWithSnapshot(xlrec->snapshotConflictHorizon, xlrec->isCatalogRel, rlocator); @@ -8772,7 +8783,7 @@ heap_xlog_prune(XLogReaderState *record) /* Update all line pointers per the record, and repair fragmentation */ if (nredirected > 0 || ndead > 0 || nunused > 0) - heap_page_prune_execute(buffer, + heap_page_prune_execute(buffer, lp_truncate_only, redirected, nredirected, nowdead, ndead, nowunused, nunused); @@ -8819,7 +8830,7 @@ heap_xlog_prune(XLogReaderState *record) UnlockReleaseBuffer(buffer); /* - * After pruning records from a page, it's useful to update the FSM + * After modifying records on a page, it's useful to update the FSM * about it, as it may cause the page become target for insertions * later even if vacuum decides not to visit it (which is possible if * gets marked all-visible.) @@ -8831,78 +8842,6 @@ heap_xlog_prune(XLogReaderState *record) } } -/* - * Handles XLOG_HEAP2_VACUUM record type. - * - * Acquires an ordinary exclusive lock only. - */ -static void -heap_xlog_vacuum(XLogReaderState *record) -{ - XLogRecPtr lsn = record->EndRecPtr; - xl_heap_vacuum *xlrec = (xl_heap_vacuum *) XLogRecGetData(record); - Buffer buffer; - BlockNumber blkno; - XLogRedoAction action; - - /* - * If we have a full-page image, restore it (without using a cleanup lock) - * and we're done. - */ - action = XLogReadBufferForRedoExtended(record, 0, RBM_NORMAL, false, - &buffer); - if (action == BLK_NEEDS_REDO) - { - Page page = (Page) BufferGetPage(buffer); - OffsetNumber *nowunused; - Size datalen; - OffsetNumber *offnum; - - nowunused = (OffsetNumber *) XLogRecGetBlockData(record, 0, &datalen); - - /* Shouldn't be a record unless there's something to do */ - Assert(xlrec->nunused > 0); - - /* Update all now-unused line pointers */ - offnum = nowunused; - for (int i = 0; i < xlrec->nunused; i++) - { - OffsetNumber off = *offnum++; - ItemId lp = PageGetItemId(page, off); - - Assert(ItemIdIsDead(lp) && !ItemIdHasStorage(lp)); - ItemIdSetUnused(lp); - } - - /* Attempt to truncate line pointer array now */ - PageTruncateLinePointerArray(page); - - PageSetLSN(page, lsn); - MarkBufferDirty(buffer); - } - - if (BufferIsValid(buffer)) - { - Size freespace = PageGetHeapFreeSpace(BufferGetPage(buffer)); - RelFileLocator rlocator; - - XLogRecGetBlockTag(record, 0, &rlocator, NULL, &blkno); - - UnlockReleaseBuffer(buffer); - - /* - * After vacuuming LP_DEAD items from a page, it's useful to update - * the FSM about it, as it may cause the page become target for - * insertions later even if vacuum decides not to visit it (which is - * possible if gets marked all-visible.) - * - * Do this regardless of a full-page image being applied, since the - * FSM data is not in the page anyway. - */ - XLogRecordPageWithFreeSpace(rlocator, blkno, freespace); - } -} - /* * Replay XLOG_HEAP2_VISIBLE record. * @@ -9943,9 +9882,6 @@ heap2_redo(XLogReaderState *record) case XLOG_HEAP2_PRUNE: heap_xlog_prune(record); break; - case XLOG_HEAP2_VACUUM: - heap_xlog_vacuum(record); - break; case XLOG_HEAP2_VISIBLE: heap_xlog_visible(record); break; diff --git a/src/backend/access/heap/pruneheap.c b/src/backend/access/heap/pruneheap.c index 19b50931b90..135fe2dba3e 100644 --- a/src/backend/access/heap/pruneheap.c +++ b/src/backend/access/heap/pruneheap.c @@ -601,7 +601,7 @@ heap_page_prune_and_freeze(Relation relation, Buffer buffer, */ if (do_prune) { - heap_page_prune_execute(buffer, + heap_page_prune_execute(buffer, false, prstate.redirected, prstate.nredirected, prstate.nowdead, prstate.ndead, prstate.nowunused, prstate.nunused); @@ -668,12 +668,16 @@ log_heap_prune_and_freeze(Relation relation, Buffer buffer, OffsetNumber offsets[MaxHeapTuplesPerPage]; bool do_freeze = presult->nfrozen > 0; + xlrec.flags = 0; + xlrec.isCatalogRel = RelationIsAccessibleInLogicalDecoding(relation); xlrec.nredirected = prstate->nredirected; xlrec.ndead = prstate->ndead; xlrec.nunused = prstate->nunused; xlrec.nplans = 0; + xlrec.flags |= XLHP_HAS_CONFLICT_HORIZON; + /* * The snapshotConflictHorizon for the whole record should be the most * conservative of all the horizons calculated for any of the possible @@ -1149,7 +1153,7 @@ heap_prune_record_unused(PruneState *prstate, OffsetNumber offnum) * cleanup lock on the buffer. */ void -heap_page_prune_execute(Buffer buffer, +heap_page_prune_execute(Buffer buffer, bool lp_truncate_only, OffsetNumber *redirected, int nredirected, OffsetNumber *nowdead, int ndead, OffsetNumber *nowunused, int nunused) @@ -1171,6 +1175,7 @@ heap_page_prune_execute(Buffer buffer, ItemId tolp PG_USED_FOR_ASSERTS_ONLY; #ifdef USE_ASSERT_CHECKING + Assert(!lp_truncate_only); /* * Any existing item that we set as an LP_REDIRECT (any 'from' item) @@ -1226,6 +1231,7 @@ heap_page_prune_execute(Buffer buffer, ItemId lp = PageGetItemId(page, off); #ifdef USE_ASSERT_CHECKING + Assert(!lp_truncate_only); /* * An LP_DEAD line pointer must be left behind when the original item @@ -1259,23 +1265,29 @@ heap_page_prune_execute(Buffer buffer, #ifdef USE_ASSERT_CHECKING - /* - * When heap_page_prune_and_freeze() was called, mark_unused_now may - * have been passed as true, which allows would-be LP_DEAD items to be - * made LP_UNUSED instead. This is only possible if the relation has - * no indexes. If there are any dead items, then mark_unused_now was - * not true and every item being marked LP_UNUSED must refer to a - * heap-only tuple. - */ - if (ndead > 0) + if (lp_truncate_only) { - Assert(ItemIdHasStorage(lp) && ItemIdIsNormal(lp)); - htup = (HeapTupleHeader) PageGetItem(page, lp); - Assert(HeapTupleHeaderIsHeapOnly(htup)); + /* Setting LP_DEAD to LP_UNUSED in vacuum's second pass */ + Assert(ItemIdIsDead(lp) && !ItemIdHasStorage(lp)); } else { - Assert(ItemIdIsUsed(lp)); + /* + * When heap_page_prune_and_freeze() was called, mark_unused_now + * may have been passed as true, which allows would-be LP_DEAD + * items to be made LP_UNUSED instead. This is only possible if + * the relation has no indexes. If there are any dead items, then + * mark_unused_now was not true and every item being marked + * LP_UNUSED must refer to a heap-only tuple. + */ + if (ndead > 0) + { + Assert(ItemIdHasStorage(lp) && ItemIdIsNormal(lp)); + htup = (HeapTupleHeader) PageGetItem(page, lp); + Assert(HeapTupleHeaderIsHeapOnly(htup)); + } + else + Assert(ItemIdIsUsed(lp)); } #endif @@ -1283,17 +1295,22 @@ heap_page_prune_execute(Buffer buffer, ItemIdSetUnused(lp); } - /* - * Finally, repair any fragmentation, and update the page's hint bit about - * whether it has free pointers. - */ - PageRepairFragmentation(page); + if (lp_truncate_only) + PageTruncateLinePointerArray(page); + else + { + /* + * Finally, repair any fragmentation, and update the page's hint bit + * about whether it has free pointers. + */ + PageRepairFragmentation(page); - /* - * Now that the page has been modified, assert that redirect items still - * point to valid targets. - */ - page_verify_redirects(page); + /* + * Now that the page has been modified, assert that redirect items + * still point to valid targets. + */ + page_verify_redirects(page); + } } diff --git a/src/backend/access/heap/vacuumlazy.c b/src/backend/access/heap/vacuumlazy.c index c4553a4159c..9dfb56475cf 100644 --- a/src/backend/access/heap/vacuumlazy.c +++ b/src/backend/access/heap/vacuumlazy.c @@ -2394,18 +2394,24 @@ lazy_vacuum_heap_page(LVRelState *vacrel, BlockNumber blkno, Buffer buffer, /* XLOG stuff */ if (RelationNeedsWAL(vacrel->rel)) { - xl_heap_vacuum xlrec; + xl_heap_prune xlrec; XLogRecPtr recptr; + xlrec.flags = XLHP_LP_TRUNCATE_ONLY; + xlrec.snapshotConflictHorizon = InvalidTransactionId; + xlrec.nplans = 0; + xlrec.nredirected = 0; + xlrec.ndead = 0; xlrec.nunused = nunused; + xlrec.isCatalogRel = RelationIsAccessibleInLogicalDecoding(vacrel->rel); XLogBeginInsert(); - XLogRegisterData((char *) &xlrec, SizeOfHeapVacuum); + XLogRegisterData((char *) &xlrec, SizeOfHeapPrune); XLogRegisterBuffer(0, buffer, REGBUF_STANDARD); XLogRegisterBufData(0, (char *) unused, nunused * sizeof(OffsetNumber)); - recptr = XLogInsert(RM_HEAP2_ID, XLOG_HEAP2_VACUUM); + recptr = XLogInsert(RM_HEAP2_ID, XLOG_HEAP2_PRUNE); PageSetLSN(page, recptr); } diff --git a/src/backend/access/rmgrdesc/heapdesc.c b/src/backend/access/rmgrdesc/heapdesc.c index 9f0a0341d40..ea03f902fc4 100644 --- a/src/backend/access/rmgrdesc/heapdesc.c +++ b/src/backend/access/rmgrdesc/heapdesc.c @@ -242,23 +242,6 @@ heap2_desc(StringInfo buf, XLogReaderState *record) } } } - else if (info == XLOG_HEAP2_VACUUM) - { - xl_heap_vacuum *xlrec = (xl_heap_vacuum *) rec; - - appendStringInfo(buf, "nunused: %u", xlrec->nunused); - - if (XLogRecHasBlockData(record, 0)) - { - OffsetNumber *nowunused; - - nowunused = (OffsetNumber *) XLogRecGetBlockData(record, 0, NULL); - - appendStringInfoString(buf, ", unused:"); - array_desc(buf, nowunused, sizeof(OffsetNumber), xlrec->nunused, - &offset_elem_desc, NULL); - } - } else if (info == XLOG_HEAP2_VISIBLE) { xl_heap_visible *xlrec = (xl_heap_visible *) rec; @@ -360,9 +343,6 @@ heap2_identify(uint8 info) case XLOG_HEAP2_PRUNE: id = "PRUNE"; break; - case XLOG_HEAP2_VACUUM: - id = "VACUUM"; - break; case XLOG_HEAP2_VISIBLE: id = "VISIBLE"; break; diff --git a/src/backend/replication/logical/decode.c b/src/backend/replication/logical/decode.c index f77051572fd..38d1bdd825e 100644 --- a/src/backend/replication/logical/decode.c +++ b/src/backend/replication/logical/decode.c @@ -446,7 +446,6 @@ heap2_decode(LogicalDecodingContext *ctx, XLogRecordBuffer *buf) * interested in. */ case XLOG_HEAP2_PRUNE: - case XLOG_HEAP2_VACUUM: case XLOG_HEAP2_VISIBLE: case XLOG_HEAP2_LOCK_UPDATED: break; diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h index 321a46185e1..d5cb8f99cac 100644 --- a/src/include/access/heapam.h +++ b/src/include/access/heapam.h @@ -349,7 +349,7 @@ extern void heap_page_prune_and_freeze(Relation relation, Buffer buffer, HeapPageFreeze *pagefrz, PruneFreezeResult *presult, OffsetNumber *off_loc); -extern void heap_page_prune_execute(Buffer buffer, +extern void heap_page_prune_execute(Buffer buffer, bool lp_truncate_only, OffsetNumber *redirected, int nredirected, OffsetNumber *nowdead, int ndead, OffsetNumber *nowunused, int nunused); diff --git a/src/include/access/heapam_xlog.h b/src/include/access/heapam_xlog.h index fe4a8ff0620..2393540cf68 100644 --- a/src/include/access/heapam_xlog.h +++ b/src/include/access/heapam_xlog.h @@ -52,11 +52,10 @@ */ #define XLOG_HEAP2_REWRITE 0x00 #define XLOG_HEAP2_PRUNE 0x10 -#define XLOG_HEAP2_VACUUM 0x20 -#define XLOG_HEAP2_VISIBLE 0x30 -#define XLOG_HEAP2_MULTI_INSERT 0x40 -#define XLOG_HEAP2_LOCK_UPDATED 0x50 -#define XLOG_HEAP2_NEW_CID 0x60 +#define XLOG_HEAP2_VISIBLE 0x20 +#define XLOG_HEAP2_MULTI_INSERT 0x30 +#define XLOG_HEAP2_LOCK_UPDATED 0x40 +#define XLOG_HEAP2_NEW_CID 0x50 /* * xl_heap_insert/xl_heap_multi_insert flag values, 8 bits are available. @@ -266,6 +265,7 @@ typedef struct xl_heap_freeze_plan */ typedef struct xl_heap_prune { + uint8 flags; TransactionId snapshotConflictHorizon; uint16 nplans; uint16 nredirected; @@ -288,19 +288,22 @@ typedef struct xl_heap_prune #define SizeOfHeapPrune (offsetof(xl_heap_prune, isCatalogRel) + sizeof(bool)) +/* Flags for xl_heap_prune */ + /* - * The vacuum page record is similar to the prune record, but can only mark - * already LP_DEAD items LP_UNUSED (during VACUUM's second heap pass) - * - * Acquires an ordinary exclusive lock only. + * During vacuum's second pass which sets LP_DEAD items LP_UNUSED, we will only + * truncate the line pointer array, not call PageRepairFragmentation. We need + * this flag to differentiate what kind of lock (exclusive or cleanup) to take + * on the buffer and whether to call PageTruncateLinePointerArray() or + * PageRepairFragementation(). */ -typedef struct xl_heap_vacuum -{ - uint16 nunused; - /* OFFSET NUMBERS are in the block reference 0 */ -} xl_heap_vacuum; +#define XLHP_LP_TRUNCATE_ONLY (1 << 1) -#define SizeOfHeapVacuum (offsetof(xl_heap_vacuum, nunused) + sizeof(uint16)) +/* + * Vacuum's first pass and on-access pruning may need to include a snapshot + * conflict horizon. + */ +#define XLHP_HAS_CONFLICT_HORIZON (1 << 2) /* flags for infobits_set */ #define XLHL_XMAX_IS_MULTI 0x01 -- 2.40.1