diff options
| -rw-r--r-- | src/backend/access/heap/vacuumlazy.c | 43 |
1 files changed, 19 insertions, 24 deletions
diff --git a/src/backend/access/heap/vacuumlazy.c b/src/backend/access/heap/vacuumlazy.c index 9f1f8e340d9..fe18af61b37 100644 --- a/src/backend/access/heap/vacuumlazy.c +++ b/src/backend/access/heap/vacuumlazy.c @@ -110,10 +110,9 @@ #define BYPASS_THRESHOLD_PAGES 0.02 /* i.e. 2% of rel_pages */ /* - * When a table is small (i.e. smaller than this), save cycles by avoiding - * repeated failsafe checks + * Perform a failsafe check every 4GB during the heap scan, approximately */ -#define FAILSAFE_MIN_PAGES \ +#define FAILSAFE_EVERY_PAGES \ ((BlockNumber) (((uint64) 4 * 1024 * 1024 * 1024) / BLCKSZ)) /* @@ -890,6 +889,7 @@ lazy_scan_heap(LVRelState *vacrel, VacuumParams *params, bool aggressive) BlockNumber nblocks, blkno, next_unskippable_block, + next_failsafe_block, next_fsm_block_to_vacuum; PGRUsage ru0; Buffer vmbuffer = InvalidBuffer; @@ -919,6 +919,7 @@ lazy_scan_heap(LVRelState *vacrel, VacuumParams *params, bool aggressive) nblocks = RelationGetNumberOfBlocks(vacrel->rel); next_unskippable_block = 0; + next_failsafe_block = 0; next_fsm_block_to_vacuum = 0; vacrel->rel_pages = nblocks; vacrel->scanned_pages = 0; @@ -1131,6 +1132,20 @@ lazy_scan_heap(LVRelState *vacrel, VacuumParams *params, bool aggressive) vacuum_delay_point(); /* + * Regularly check if wraparound failsafe should trigger. + * + * There is a similar check inside lazy_vacuum_all_indexes(), but + * relfrozenxid might start to look dangerously old before we reach + * that point. This check also provides failsafe coverage for the + * one-pass strategy case. + */ + if (blkno - next_failsafe_block >= FAILSAFE_EVERY_PAGES) + { + lazy_check_wraparound_failsafe(vacrel); + next_failsafe_block = blkno; + } + + /* * Consider if we definitely have enough space to process TIDs on page * already. If we are close to overrunning the available space for * dead-tuple TIDs, pause and do a cycle of vacuuming before we tackle @@ -1375,17 +1390,12 @@ lazy_scan_heap(LVRelState *vacrel, VacuumParams *params, bool aggressive) * Periodically perform FSM vacuuming to make newly-freed * space visible on upper FSM pages. Note we have not yet * performed FSM processing for blkno. - * - * Call lazy_check_wraparound_failsafe() here, too, since we - * also don't want to do that too frequently, or too - * infrequently. */ if (blkno - next_fsm_block_to_vacuum >= VACUUM_FSM_EVERY_PAGES) { FreeSpaceMapVacuumRange(vacrel->rel, next_fsm_block_to_vacuum, blkno); next_fsm_block_to_vacuum = blkno; - lazy_check_wraparound_failsafe(vacrel); } /* @@ -2558,7 +2568,6 @@ lazy_check_needs_freeze(Buffer buf, bool *hastup, LVRelState *vacrel) /* * Trigger the failsafe to avoid wraparound failure when vacrel table has a * relfrozenxid and/or relminmxid that is dangerously far in the past. - * * Triggering the failsafe makes the ongoing VACUUM bypass any further index * vacuuming and heap vacuuming. Truncating the heap is also bypassed. * @@ -2567,24 +2576,10 @@ lazy_check_needs_freeze(Buffer buf, bool *hastup, LVRelState *vacrel) * that it started out with. * * Returns true when failsafe has been triggered. - * - * Caller is expected to call here before and after vacuuming each index in - * the case of two-pass VACUUM, or every VACUUM_FSM_EVERY_PAGES blocks in the - * case of no-indexes/one-pass VACUUM. - * - * There is also a precheck before the first pass over the heap begins, which - * is helpful when the failsafe initially triggers during a non-aggressive - * VACUUM -- the automatic aggressive vacuum to prevent wraparound that - * follows can independently trigger the failsafe right away. */ static bool lazy_check_wraparound_failsafe(LVRelState *vacrel) { - /* Avoid calling vacuum_xid_failsafe_check() very frequently */ - if (vacrel->num_index_scans == 0 && - vacrel->rel_pages <= FAILSAFE_MIN_PAGES) - return false; - /* Don't warn more than once per VACUUM */ if (vacrel->do_failsafe) return true; @@ -2600,7 +2595,7 @@ lazy_check_wraparound_failsafe(LVRelState *vacrel) vacrel->do_failsafe = true; ereport(WARNING, - (errmsg("abandoned index vacuuming of table \"%s.%s.%s\" as a failsafe after %d index scans", + (errmsg("bypassing nonessential maintenance of table \"%s.%s.%s\" as a failsafe after %d index scans", get_database_name(MyDatabaseId), vacrel->relnamespace, vacrel->relname, |