From b8dacf8fed00b3d1fcf59e61adb1541ba68746a0 Mon Sep 17 00:00:00 2001 From: Melanie Plageman Date: Tue, 17 Jun 2025 17:40:28 -0400 Subject: [PATCH v1 05/14] Eliminate xl_heap_visible in COPY FREEZE Instead of emitting a separate WAL record for setting the VM bits in xl_heap_visible, include the required update in the xl_heap_multi_insert record instead. --- src/backend/access/heap/heapam.c | 42 +++++++++++++++++--------- src/backend/access/heap/heapam_xlog.c | 37 ++++++++++++++++++++++- src/backend/access/rmgrdesc/heapdesc.c | 5 +++ 3 files changed, 69 insertions(+), 15 deletions(-) diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c index 15dc3d88843..3d9b114b4e8 100644 --- a/src/backend/access/heap/heapam.c +++ b/src/backend/access/heap/heapam.c @@ -2493,9 +2493,6 @@ heap_multi_insert(Relation relation, TupleTableSlot **slots, int ntuples, /* * 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)) { @@ -2506,6 +2503,22 @@ heap_multi_insert(Relation relation, TupleTableSlot **slots, int ntuples, vmbuffer, VISIBILITYMAP_VALID_BITS); } + /* + * If we're only adding already frozen rows to a previously empty + * page, mark it as all-visible. And if we've frozen everything on the + * page, update the visibility map. We're already holding a pin on the + * vmbuffer. + */ + else if (all_frozen_set) + { + LockBuffer(vmbuffer, BUFFER_LOCK_EXCLUSIVE); + heap_page_set_vm(relation, + BufferGetBlockNumber(buffer), buffer, + vmbuffer, + VISIBILITYMAP_ALL_VISIBLE | + VISIBILITYMAP_ALL_FROZEN); + } + /* * XXX Should we set PageSetPrunable on this page ? See heap_insert() */ @@ -2552,6 +2565,12 @@ heap_multi_insert(Relation relation, TupleTableSlot **slots, int ntuples, xlrec->flags = 0; if (all_visible_cleared) xlrec->flags = XLH_INSERT_ALL_VISIBLE_CLEARED; + + /* + * We don't have to worry about including a conflict xid in the + * WAL record as HEAP_INSERT_FROZEN intentionally violates + * visibility rules. + */ if (all_frozen_set) xlrec->flags = XLH_INSERT_ALL_FROZEN_SET; @@ -2614,7 +2633,10 @@ heap_multi_insert(Relation relation, TupleTableSlot **slots, int ntuples, XLogBeginInsert(); XLogRegisterData(xlrec, tupledata - scratch.data); + XLogRegisterBuffer(0, buffer, REGBUF_STANDARD | bufflags); + if (all_frozen_set) + XLogRegisterBuffer(1, vmbuffer, 0); XLogRegisterBufData(0, tupledata, totaldatalen); @@ -2624,22 +2646,14 @@ heap_multi_insert(Relation relation, TupleTableSlot **slots, int ntuples, recptr = XLogInsert(RM_HEAP2_ID, info); PageSetLSN(page, recptr); + if (all_frozen_set) + PageSetLSN(BufferGetPage(vmbuffer), recptr); } END_CRIT_SECTION(); - /* - * If we've frozen everything on the page, update the visibilitymap. - * We're already holding pin on the vmbuffer. It's fine to use - * InvalidTransactionId here - this is only used when - * HEAP_INSERT_FROZEN is specified, which intentionally violates - * visibility rules. - */ if (all_frozen_set) - heap_page_set_vm_and_log(relation, BufferGetBlockNumber(buffer), buffer, - vmbuffer, - InvalidTransactionId, - VISIBILITYMAP_ALL_VISIBLE | VISIBILITYMAP_ALL_FROZEN); + LockBuffer(vmbuffer, BUFFER_LOCK_UNLOCK); UnlockReleaseBuffer(buffer); ndone += nthispage; diff --git a/src/backend/access/heap/heapam_xlog.c b/src/backend/access/heap/heapam_xlog.c index cfd4fc3327d..a0f3673621a 100644 --- a/src/backend/access/heap/heapam_xlog.c +++ b/src/backend/access/heap/heapam_xlog.c @@ -552,6 +552,7 @@ heap_xlog_multi_insert(XLogReaderState *record) int i; bool isinit = (XLogRecGetInfo(record) & XLOG_HEAP_INIT_PAGE) != 0; XLogRedoAction action; + Buffer vmbuffer = InvalidBuffer; /* * Insertion doesn't overwrite MVCC data, so no conflict processing is @@ -572,11 +573,11 @@ heap_xlog_multi_insert(XLogReaderState *record) if (xlrec->flags & XLH_INSERT_ALL_VISIBLE_CLEARED) { Relation reln = CreateFakeRelcacheEntry(rlocator); - Buffer vmbuffer = InvalidBuffer; visibilitymap_pin(reln, blkno, &vmbuffer); visibilitymap_clear(reln, blkno, vmbuffer, VISIBILITYMAP_VALID_BITS); ReleaseBuffer(vmbuffer); + vmbuffer = InvalidBuffer; FreeFakeRelcacheEntry(reln); } @@ -663,6 +664,40 @@ heap_xlog_multi_insert(XLogReaderState *record) if (BufferIsValid(buffer)) UnlockReleaseBuffer(buffer); + buffer = InvalidBuffer; + + /* + * Now read and update the VM block. Even if we skipped updating the heap + * page due to the file being dropped or truncated later in recovery, it's + * still safe to update the visibility map. Any WAL record that clears + * the visibility map bit does so before checking the page LSN, so any + * bits that need to be cleared will still be cleared. + * + * It is only okay to set the VM bits without holding the heap page lock + * because we can expect no other writers of this page. + */ + if (xlrec->flags & XLH_INSERT_ALL_FROZEN_SET && + XLogReadBufferForRedoExtended(record, 1, RBM_ZERO_ON_ERROR, false, + &vmbuffer) == BLK_NEEDS_REDO) + { + + uint8 old_vmbits = 0; + Relation reln = CreateFakeRelcacheEntry(rlocator); + + visibilitymap_pin(reln, blkno, &vmbuffer); + old_vmbits = visibilitymap_set_vmbyte(reln, blkno, + vmbuffer, + VISIBILITYMAP_ALL_VISIBLE | + VISIBILITYMAP_ALL_FROZEN); + Assert((old_vmbits & VISIBILITYMAP_VALID_BITS) == 0); + (void) old_vmbits; /* Silence compiler */ + PageSetLSN(BufferGetPage(vmbuffer), lsn); + FreeFakeRelcacheEntry(reln); + } + + if (BufferIsValid(vmbuffer)) + UnlockReleaseBuffer(vmbuffer); + /* * If the page is running low on free space, update the FSM as well. * Arbitrarily, our definition of "low" is less than 20%. We can't do much diff --git a/src/backend/access/rmgrdesc/heapdesc.c b/src/backend/access/rmgrdesc/heapdesc.c index 82b62c95de5..b48d7dc1d24 100644 --- a/src/backend/access/rmgrdesc/heapdesc.c +++ b/src/backend/access/rmgrdesc/heapdesc.c @@ -16,6 +16,7 @@ #include "access/heapam_xlog.h" #include "access/rmgrdesc_utils.h" +#include "access/visibilitymapdefs.h" #include "storage/standbydefs.h" /* @@ -354,6 +355,10 @@ heap2_desc(StringInfo buf, XLogReaderState *record) appendStringInfo(buf, "ntuples: %d, flags: 0x%02X", xlrec->ntuples, xlrec->flags); + if (xlrec->flags & XLH_INSERT_ALL_FROZEN_SET) + appendStringInfo(buf, ", vm_flags: 0x%02X", + VISIBILITYMAP_ALL_VISIBLE | VISIBILITYMAP_ALL_FROZEN); + if (XLogRecHasBlockData(record, 0) && !isinit) { appendStringInfoString(buf, ", offsets:"); -- 2.34.1