From 4ec10accb276d9ecde461c6cde0be5a610ed3dc6 Mon Sep 17 00:00:00 2001 From: Justin Pryzby Date: Sun, 29 Aug 2021 15:57:09 -0500 Subject: [PATCH 1/3] VACUUM FULL/CLUSTER: set VM and page-level visibility bits From: Alexander Korotkov write-vm-during-cluster-3-rebase --- src/backend/access/heap/rewriteheap.c | 131 +++++++++++++++++++++++- src/backend/access/heap/visibilitymap.c | 18 ---- src/include/access/visibilitymap.h | 18 ++++ 3 files changed, 147 insertions(+), 20 deletions(-) diff --git a/src/backend/access/heap/rewriteheap.c b/src/backend/access/heap/rewriteheap.c index 986a776bbd..af0d1b2d0c 100644 --- a/src/backend/access/heap/rewriteheap.c +++ b/src/backend/access/heap/rewriteheap.c @@ -110,6 +110,7 @@ #include "access/heaptoast.h" #include "access/rewriteheap.h" #include "access/transam.h" +#include "access/visibilitymap.h" #include "access/xact.h" #include "access/xloginsert.h" #include "catalog/catalog.h" @@ -152,6 +153,11 @@ typedef struct RewriteStateData HTAB *rs_old_new_tid_map; /* unmatched B tuples */ HTAB *rs_logical_mappings; /* logical remapping files */ uint32 rs_num_rewrite_mappings; /* # in memory mappings */ + Page rs_vm_buffer; /* visibility map page */ + BlockNumber rs_vm_blockno; /* block number of visibility page */ + BlockNumber rs_vm_buffer_valid; /* T if any bits are set */ + bool rs_all_visible; /* all visible flag for rs_buffer */ + bool rs_all_frozen; /* all frozen flag for rs_buffer */ } RewriteStateData; /* @@ -213,6 +219,9 @@ typedef struct RewriteMappingDataEntry /* prototypes for internal functions */ +static void rewrite_flush_vm_page(RewriteState state); +static void rewrite_set_vm_flags(RewriteState state); +static void rewrite_update_vm_flags(RewriteState state, HeapTuple tuple); static void raw_heap_insert(RewriteState state, HeapTuple tup); /* internal logical remapping prototypes */ @@ -264,6 +273,11 @@ begin_heap_rewrite(Relation old_heap, Relation new_heap, TransactionId oldest_xm state->rs_freeze_xid = freeze_xid; state->rs_cutoff_multi = cutoff_multi; state->rs_cxt = rw_cxt; + state->rs_vm_buffer = (Page) palloc(BLCKSZ); + state->rs_vm_blockno = HEAPBLK_TO_MAPBLOCK(state->rs_blockno); + state->rs_vm_buffer_valid = false; + state->rs_all_visible = true; + state->rs_all_frozen = true; /* Initialize hash tables used to track update chains */ hash_ctl.keysize = sizeof(TidHashKey); @@ -284,6 +298,9 @@ begin_heap_rewrite(Relation old_heap, Relation new_heap, TransactionId oldest_xm &hash_ctl, HASH_ELEM | HASH_BLOBS | HASH_CONTEXT); + if (!smgrexists(RelationGetSmgr(state->rs_new_rel), VISIBILITYMAP_FORKNUM)) + smgrcreate(RelationGetSmgr(state->rs_new_rel), VISIBILITYMAP_FORKNUM, false); + MemoryContextSwitchTo(old_cxt); logical_begin_heap_rewrite(state); @@ -317,6 +334,9 @@ end_heap_rewrite(RewriteState state) /* Write the last page, if any */ if (state->rs_buffer_valid) { + if (state->rs_all_visible) + PageSetAllVisible(state->rs_buffer); + if (RelationNeedsWAL(state->rs_new_rel)) log_newpage(&state->rs_new_rel->rd_node, MAIN_FORKNUM, @@ -326,10 +346,16 @@ end_heap_rewrite(RewriteState state) PageSetChecksumInplace(state->rs_buffer, state->rs_blockno); - smgrextend(RelationGetSmgr(state->rs_new_rel), MAIN_FORKNUM, - state->rs_blockno, (char *) state->rs_buffer, true); + smgrextend(RelationGetSmgr(state->rs_new_rel), MAIN_FORKNUM, state->rs_blockno, + (char *) state->rs_buffer, true); + + rewrite_set_vm_flags(state); } + /* Write the last VM page too */ + if (state->rs_vm_buffer_valid) + rewrite_flush_vm_page(state); + /* * When we WAL-logged rel pages, we must nonetheless fsync them. The * reason is the same as in storage.c's RelationCopyStorage(): we're @@ -338,7 +364,11 @@ end_heap_rewrite(RewriteState state) * wrote before the checkpoint. */ if (RelationNeedsWAL(state->rs_new_rel)) + { + /* for an empty table, this could be first smgr access */ smgrimmedsync(RelationGetSmgr(state->rs_new_rel), MAIN_FORKNUM); + smgrimmedsync(RelationGetSmgr(state->rs_new_rel), VISIBILITYMAP_FORKNUM); + } logical_end_heap_rewrite(state); @@ -346,6 +376,97 @@ end_heap_rewrite(RewriteState state) MemoryContextDelete(state->rs_cxt); } +/* Write contents of VM page */ +static void +rewrite_flush_vm_page(RewriteState state) +{ + Assert(state->rs_vm_buffer_valid); + + if (RelationNeedsWAL(state->rs_new_rel)) + log_newpage(&state->rs_new_rel->rd_node, + VISIBILITYMAP_FORKNUM, + state->rs_vm_blockno, + state->rs_vm_buffer, + true); + + PageSetChecksumInplace(state->rs_vm_buffer, state->rs_vm_blockno); + + smgrextend(RelationGetSmgr(state->rs_new_rel), VISIBILITYMAP_FORKNUM, + state->rs_vm_blockno, (char *) state->rs_vm_buffer, true); + + state->rs_vm_buffer_valid = false; +} + +/* Set VM flags to the VM page */ +static void +rewrite_set_vm_flags(RewriteState state) +{ + BlockNumber mapBlock = HEAPBLK_TO_MAPBLOCK(state->rs_blockno); + uint32 mapByte = HEAPBLK_TO_MAPBYTE(state->rs_blockno); + uint8 mapOffset = HEAPBLK_TO_OFFSET(state->rs_blockno); + char *map; + uint8 flags; + + if (mapBlock != state->rs_vm_blockno && state->rs_vm_buffer_valid) + rewrite_flush_vm_page(state); + + if (!state->rs_vm_buffer_valid) + { + PageInit(state->rs_vm_buffer, BLCKSZ, 0); + state->rs_vm_blockno = mapBlock; + state->rs_vm_buffer_valid = true; + } + + flags = (state->rs_all_visible ? VISIBILITYMAP_ALL_VISIBLE : 0) | + (state->rs_all_frozen ? VISIBILITYMAP_ALL_FROZEN : 0); + + map = PageGetContents(state->rs_vm_buffer); + map[mapByte] |= (flags << mapOffset); +} + +/* + * Update rs_all_visible and rs_all_frozen flags according to the tuple. We + * use simplified check assuming that HeapTupleSatisfiesVacuum() should already + * set tuple hint bits. + */ +static void +rewrite_update_vm_flags(RewriteState state, HeapTuple tuple) +{ + TransactionId xmin; + + if (!state->rs_all_visible) + return; + + if (!HeapTupleHeaderXminCommitted(tuple->t_data)) + { + state->rs_all_visible = false; + state->rs_all_frozen = false; + return; + } + + xmin = HeapTupleHeaderGetXmin(tuple->t_data); + if (!TransactionIdPrecedes(xmin, state->rs_oldest_xmin)) + { + state->rs_all_visible = false; + state->rs_all_frozen = false; + return; + } + + if (!(tuple->t_data->t_infomask & HEAP_XMAX_INVALID) && + !HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_data->t_infomask)) + { + state->rs_all_visible = false; + state->rs_all_frozen = false; + return; + } + + if (!state->rs_all_frozen) + return; + + if (heap_tuple_needs_eventual_freeze(tuple->t_data)) + state->rs_all_frozen = false; +} + /* * Add a tuple to the new heap. * @@ -472,6 +593,7 @@ rewrite_heap_tuple(RewriteState state, /* Insert the tuple and find out where it's put in new_heap */ raw_heap_insert(state, new_tuple); + rewrite_update_vm_flags(state, new_tuple); new_tid = new_tuple->t_self; logical_rewrite_heap_tuple(state, old_tid, new_tuple); @@ -677,6 +799,9 @@ raw_heap_insert(RewriteState state, HeapTuple tup) * enforce saveFreeSpace unconditionally. */ + if (state->rs_all_visible) + PageSetAllVisible(page); + /* XLOG stuff */ if (RelationNeedsWAL(state->rs_new_rel)) log_newpage(&state->rs_new_rel->rd_node, @@ -695,6 +820,8 @@ raw_heap_insert(RewriteState state, HeapTuple tup) smgrextend(RelationGetSmgr(state->rs_new_rel), MAIN_FORKNUM, state->rs_blockno, (char *) page, true); + rewrite_set_vm_flags(state); + state->rs_blockno++; state->rs_buffer_valid = false; } diff --git a/src/backend/access/heap/visibilitymap.c b/src/backend/access/heap/visibilitymap.c index 114fbbdd30..dd0e686a9f 100644 --- a/src/backend/access/heap/visibilitymap.c +++ b/src/backend/access/heap/visibilitymap.c @@ -99,24 +99,6 @@ /*#define TRACE_VISIBILITYMAP */ -/* - * Size of the bitmap on each visibility map page, in bytes. There's no - * extra headers, so the whole page minus the standard page header is - * used for the bitmap. - */ -#define MAPSIZE (BLCKSZ - MAXALIGN(SizeOfPageHeaderData)) - -/* Number of heap blocks we can represent in one byte */ -#define HEAPBLOCKS_PER_BYTE (BITS_PER_BYTE / BITS_PER_HEAPBLOCK) - -/* Number of heap blocks we can represent in one visibility map page. */ -#define HEAPBLOCKS_PER_PAGE (MAPSIZE * HEAPBLOCKS_PER_BYTE) - -/* Mapping from heap block number to the right bit in the visibility map */ -#define HEAPBLK_TO_MAPBLOCK(x) ((x) / HEAPBLOCKS_PER_PAGE) -#define HEAPBLK_TO_MAPBYTE(x) (((x) % HEAPBLOCKS_PER_PAGE) / HEAPBLOCKS_PER_BYTE) -#define HEAPBLK_TO_OFFSET(x) (((x) % HEAPBLOCKS_PER_BYTE) * BITS_PER_HEAPBLOCK) - /* Masks for counting subsets of bits in the visibility map. */ #define VISIBLE_MASK64 UINT64CONST(0x5555555555555555) /* The lower bit of each * bit pair */ diff --git a/src/include/access/visibilitymap.h b/src/include/access/visibilitymap.h index 57362c3687..39f3d59156 100644 --- a/src/include/access/visibilitymap.h +++ b/src/include/access/visibilitymap.h @@ -34,6 +34,24 @@ #define VM_ALL_FROZEN(r, b, v) \ ((visibilitymap_get_status((r), (b), (v)) & VISIBILITYMAP_ALL_FROZEN) != 0) +/* + * Size of the bitmap on each visibility map page, in bytes. There's no + * extra headers, so the whole page minus the standard page header is + * used for the bitmap. + */ +#define MAPSIZE (BLCKSZ - MAXALIGN(SizeOfPageHeaderData)) + +/* Number of heap blocks we can represent in one byte */ +#define HEAPBLOCKS_PER_BYTE (BITS_PER_BYTE / BITS_PER_HEAPBLOCK) + +/* Number of heap blocks we can represent in one visibility map page. */ +#define HEAPBLOCKS_PER_PAGE (MAPSIZE * HEAPBLOCKS_PER_BYTE) + +/* Mapping from heap block number to the right bit in the visibility map */ +#define HEAPBLK_TO_MAPBLOCK(x) ((x) / HEAPBLOCKS_PER_PAGE) +#define HEAPBLK_TO_MAPBYTE(x) (((x) % HEAPBLOCKS_PER_PAGE) / HEAPBLOCKS_PER_BYTE) +#define HEAPBLK_TO_OFFSET(x) (((x) % HEAPBLOCKS_PER_BYTE) * BITS_PER_HEAPBLOCK) + extern bool visibilitymap_clear(Relation rel, BlockNumber heapBlk, Buffer vmbuf, uint8 flags); extern void visibilitymap_pin(Relation rel, BlockNumber heapBlk, -- 2.17.0