From 2e5ed537b9053ff3212177c1732d6afa2100fa0f Mon Sep 17 00:00:00 2001 From: Melanie Plageman Date: Sun, 31 Dec 2023 11:29:02 -0500 Subject: [PATCH v5a 6/7] Vacuum first pass uses Streaming Read interface Now vacuum's first pass, which HOT prunes and records the TIDs of non-removable dead tuples, uses the streaming read API by implementing a streaming read callback which invokes heap_vac_scan_get_next_block(). --- src/backend/access/heap/vacuumlazy.c | 79 +++++++++++++++++++++------- 1 file changed, 59 insertions(+), 20 deletions(-) diff --git a/src/backend/access/heap/vacuumlazy.c b/src/backend/access/heap/vacuumlazy.c index 65d257aab83..fbbc87938e4 100644 --- a/src/backend/access/heap/vacuumlazy.c +++ b/src/backend/access/heap/vacuumlazy.c @@ -54,6 +54,7 @@ #include "storage/bufmgr.h" #include "storage/freespace.h" #include "storage/lmgr.h" +#include "storage/streaming_read.h" #include "utils/lsyscache.h" #include "utils/memutils.h" #include "utils/pg_rusage.h" @@ -168,7 +169,12 @@ typedef struct LVRelState char *relnamespace; char *relname; char *indname; /* Current index name */ - BlockNumber blkno; /* used only for heap operations */ + + /* + * The current block being processed by vacuum. Used only for heap + * operations. Primarily for error reporting and logging. + */ + BlockNumber blkno; OffsetNumber offnum; /* used only for heap operations */ VacErrPhase phase; bool verbose; /* VACUUM VERBOSE? */ @@ -189,6 +195,12 @@ typedef struct LVRelState BlockNumber missed_dead_pages; /* # pages with missed dead tuples */ BlockNumber nonempty_pages; /* actually, last nonempty page + 1 */ + /* + * The most recent block submitted in the streaming read callback by the + * first vacuum pass. + */ + BlockNumber blkno_prefetch; + /* Statistics output by us, for table */ double new_rel_tuples; /* new estimated total # of tuples */ double new_live_tuples; /* new estimated total # of live tuples */ @@ -232,7 +244,7 @@ typedef struct LVSavedErrInfo /* non-export function prototypes */ static void lazy_scan_heap(LVRelState *vacrel); -static bool heap_vac_scan_get_next_block(LVRelState *vacrel, BlockNumber next_block, +static void heap_vac_scan_get_next_block(LVRelState *vacrel, BlockNumber next_block, BlockNumber *blkno, bool *all_visible_according_to_vm); static bool lazy_scan_new_or_empty(LVRelState *vacrel, Buffer buf, @@ -416,6 +428,9 @@ heap_vacuum_rel(Relation rel, VacuumParams *params, vacrel->nonempty_pages = 0; /* dead_items_alloc allocates vacrel->dead_items later on */ + /* relies on InvalidBlockNumber overflowing to 0 */ + vacrel->blkno_prefetch = InvalidBlockNumber; + /* Allocate/initialize output statistics state */ vacrel->new_rel_tuples = 0; vacrel->new_live_tuples = 0; @@ -776,6 +791,22 @@ heap_vacuum_rel(Relation rel, VacuumParams *params, } } +static BlockNumber +vacuum_scan_pgsr_next(PgStreamingRead *pgsr, + void *pgsr_private, void *per_buffer_data) +{ + LVRelState *vacrel = pgsr_private; + bool *all_visible_according_to_vm = per_buffer_data; + + vacrel->blkno_prefetch++; + + heap_vac_scan_get_next_block(vacrel, + vacrel->blkno_prefetch, &vacrel->blkno_prefetch, + all_visible_according_to_vm); + + return vacrel->blkno_prefetch; +} + /* * lazy_scan_heap() -- workhorse function for VACUUM * @@ -815,12 +846,11 @@ heap_vacuum_rel(Relation rel, VacuumParams *params, static void lazy_scan_heap(LVRelState *vacrel) { + Buffer buf; BlockNumber rel_pages = vacrel->rel_pages, next_fsm_block_to_vacuum = 0; - bool all_visible_according_to_vm; + bool *all_visible_according_to_vm; - /* relies on InvalidBlockNumber overflowing to 0 */ - BlockNumber blkno = InvalidBlockNumber; VacDeadItems *dead_items = vacrel->dead_items; const int initprog_index[] = { PROGRESS_VACUUM_PHASE, @@ -828,6 +858,11 @@ lazy_scan_heap(LVRelState *vacrel) PROGRESS_VACUUM_MAX_DEAD_TUPLES }; int64 initprog_val[3]; + PgStreamingRead *pgsr; + + pgsr = pg_streaming_read_buffer_alloc(PGSR_FLAG_MAINTENANCE, vacrel, + sizeof(bool), vacrel->bstrategy, BMR_REL(vacrel->rel), + MAIN_FORKNUM, vacuum_scan_pgsr_next); /* Report that we're scanning the heap, advertising total # of blocks */ initprog_val[0] = PROGRESS_VACUUM_PHASE_SCAN_HEAP; @@ -838,13 +873,19 @@ lazy_scan_heap(LVRelState *vacrel) vacrel->skip.next_unskippable_block = InvalidBlockNumber; vacrel->skip.vmbuffer = InvalidBuffer; - while (heap_vac_scan_get_next_block(vacrel, blkno + 1, - &blkno, &all_visible_according_to_vm)) + while (BufferIsValid(buf = + pg_streaming_read_buffer_get_next(pgsr, (void **) &all_visible_according_to_vm))) { - Buffer buf; Page page; bool has_lpdead_items; bool got_cleanup_lock = false; + BlockNumber blkno; + + vacrel->blkno = blkno = BufferGetBlockNumber(buf); + + CheckBufferIsPinnedOnce(buf); + + page = BufferGetPage(buf); vacrel->scanned_pages++; @@ -912,9 +953,6 @@ lazy_scan_heap(LVRelState *vacrel) */ visibilitymap_pin(vacrel->rel, blkno, &vacrel->skip.vmbuffer); - buf = ReadBufferExtended(vacrel->rel, MAIN_FORKNUM, blkno, RBM_NORMAL, - vacrel->bstrategy); - page = BufferGetPage(buf); /* * We need a buffer cleanup lock to prune HOT chains and defragment @@ -970,7 +1008,7 @@ lazy_scan_heap(LVRelState *vacrel) */ if (got_cleanup_lock) lazy_scan_prune(vacrel, buf, blkno, page, - all_visible_according_to_vm, + *all_visible_according_to_vm, &has_lpdead_items); /* @@ -1027,7 +1065,7 @@ lazy_scan_heap(LVRelState *vacrel) } /* report that everything is now scanned */ - pgstat_progress_update_param(PROGRESS_VACUUM_HEAP_BLKS_SCANNED, blkno); + pgstat_progress_update_param(PROGRESS_VACUUM_HEAP_BLKS_SCANNED, vacrel->rel_pages); /* now we can compute the new value for pg_class.reltuples */ vacrel->new_live_tuples = vac_estimate_reltuples(vacrel->rel, rel_pages, @@ -1042,6 +1080,8 @@ lazy_scan_heap(LVRelState *vacrel) Max(vacrel->new_live_tuples, 0) + vacrel->recently_dead_tuples + vacrel->missed_dead_tuples; + pg_streaming_read_free(pgsr); + /* * Do index vacuuming (call each index's ambulkdelete routine), then do * related heap vacuuming @@ -1053,11 +1093,11 @@ lazy_scan_heap(LVRelState *vacrel) * Vacuum the remainder of the Free Space Map. We must do this whether or * not there were indexes, and whether or not we bypassed index vacuuming. */ - if (blkno > next_fsm_block_to_vacuum) - FreeSpaceMapVacuumRange(vacrel->rel, next_fsm_block_to_vacuum, blkno); + if (vacrel->rel_pages > next_fsm_block_to_vacuum) + FreeSpaceMapVacuumRange(vacrel->rel, next_fsm_block_to_vacuum, vacrel->rel_pages); /* report all blocks vacuumed */ - pgstat_progress_update_param(PROGRESS_VACUUM_HEAP_BLKS_VACUUMED, blkno); + pgstat_progress_update_param(PROGRESS_VACUUM_HEAP_BLKS_VACUUMED, vacrel->rel_pages); /* Do final index cleanup (call each index's amvacuumcleanup routine) */ if (vacrel->nindexes > 0 && vacrel->do_index_cleanup) @@ -1090,7 +1130,7 @@ lazy_scan_heap(LVRelState *vacrel) * * The block number and visibility status of the next block to process are set * in blkno and all_visible_according_to_vm. heap_vac_scan_get_next_block() - * returns false if there are no further blocks to process. + * sets blkno to InvalidBlockNumber if there are no further blocks to process. * * vacrel is an in/out parameter here; vacuum options and information about the * relation are read and vacrel->skippedallvis is set to ensure we don't @@ -1110,7 +1150,7 @@ lazy_scan_heap(LVRelState *vacrel) * older XIDs/MXIDs. The vacrel->skippedallvis flag will be set here when the * choice to skip such a range is actually made, making everything safe.) */ -static bool +static void heap_vac_scan_get_next_block(LVRelState *vacrel, BlockNumber next_block, BlockNumber *blkno, bool *all_visible_according_to_vm) { @@ -1119,7 +1159,7 @@ heap_vac_scan_get_next_block(LVRelState *vacrel, BlockNumber next_block, if (next_block >= vacrel->rel_pages) { *blkno = InvalidBlockNumber; - return false; + return; } if (vacrel->skip.next_unskippable_block == InvalidBlockNumber || @@ -1214,7 +1254,6 @@ heap_vac_scan_get_next_block(LVRelState *vacrel, BlockNumber next_block, *all_visible_according_to_vm = true; *blkno = next_block; - return true; } /* -- 2.40.1