diff options
Diffstat (limited to 'src/backend/commands/vacuumlazy.c')
| -rw-r--r-- | src/backend/commands/vacuumlazy.c | 66 |
1 files changed, 19 insertions, 47 deletions
diff --git a/src/backend/commands/vacuumlazy.c b/src/backend/commands/vacuumlazy.c index b53567fd536..247cc72dd1f 100644 --- a/src/backend/commands/vacuumlazy.c +++ b/src/backend/commands/vacuumlazy.c @@ -29,7 +29,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/commands/vacuumlazy.c,v 1.130 2010/02/09 00:28:30 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/commands/vacuumlazy.c,v 1.131 2010/02/09 21:43:30 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -50,7 +50,6 @@ #include "storage/bufmgr.h" #include "storage/freespace.h" #include "storage/lmgr.h" -#include "utils/inval.h" #include "utils/lsyscache.h" #include "utils/memutils.h" #include "utils/pg_rusage.h" @@ -123,7 +122,7 @@ static void lazy_cleanup_index(Relation indrel, LVRelStats *vacrelstats); static int lazy_vacuum_page(Relation onerel, BlockNumber blkno, Buffer buffer, int tupindex, LVRelStats *vacrelstats); -static bool lazy_truncate_heap(Relation onerel, LVRelStats *vacrelstats); +static void lazy_truncate_heap(Relation onerel, LVRelStats *vacrelstats); static BlockNumber count_nondeletable_pages(Relation onerel, LVRelStats *vacrelstats); static void lazy_space_alloc(LVRelStats *vacrelstats, BlockNumber relblocks); @@ -141,11 +140,8 @@ static int vac_cmp_itemptr(const void *left, const void *right); * * At entry, we have already established a transaction and opened * and locked the relation. - * - * The return value indicates whether this function has held off - * interrupts -- if true, caller must RESUME_INTERRUPTS() after commit. */ -bool +void lazy_vacuum_rel(Relation onerel, VacuumStmt *vacstmt, BufferAccessStrategy bstrategy, bool *scanned_all) { @@ -157,7 +153,6 @@ lazy_vacuum_rel(Relation onerel, VacuumStmt *vacstmt, TimestampTz starttime = 0; bool scan_all; TransactionId freezeTableLimit; - bool heldoff = false; pg_rusage_init(&ru0); @@ -194,16 +189,9 @@ lazy_vacuum_rel(Relation onerel, VacuumStmt *vacstmt, /* Done with indexes */ vac_close_indexes(nindexes, Irel, NoLock); - /* Vacuum the Free Space Map */ - FreeSpaceMapVacuum(onerel); - /* * Optionally truncate the relation. * - * NB: there should be as little code as possible after this point, - * to minimize the chance of failure as well as the time spent ignoring - * cancel/die interrupts. - * * Don't even think about it unless we have a shot at releasing a goodly * number of pages. Otherwise, the time taken isn't worth it. */ @@ -211,7 +199,10 @@ lazy_vacuum_rel(Relation onerel, VacuumStmt *vacstmt, if (possibly_freeable > 0 && (possibly_freeable >= REL_TRUNCATE_MINIMUM || possibly_freeable >= vacrelstats->rel_pages / REL_TRUNCATE_FRACTION)) - heldoff = lazy_truncate_heap(onerel, vacrelstats); + lazy_truncate_heap(onerel, vacrelstats); + + /* Vacuum the Free Space Map */ + FreeSpaceMapVacuum(onerel); /* * Update statistics in pg_class. But only if we didn't skip any pages; @@ -255,8 +246,6 @@ lazy_vacuum_rel(Relation onerel, VacuumStmt *vacstmt, if (scanned_all) *scanned_all = vacrelstats->scanned_all; - - return heldoff; } /* @@ -996,11 +985,8 @@ lazy_cleanup_index(Relation indrel, /* * lazy_truncate_heap - try to truncate off any empty pages at the end - * - * The return value indicates whether this function has held off - * interrupts -- if true, caller must RESUME_INTERRUPTS() after commit. */ -static bool +static void lazy_truncate_heap(Relation onerel, LVRelStats *vacrelstats) { BlockNumber old_rel_pages = vacrelstats->rel_pages; @@ -1016,7 +1002,7 @@ lazy_truncate_heap(Relation onerel, LVRelStats *vacrelstats) * possible considering we already hold a lower-grade lock). */ if (!ConditionalLockRelation(onerel, AccessExclusiveLock)) - return false; + return; /* * Now that we have exclusive lock, look to see if the rel has grown @@ -1029,7 +1015,7 @@ lazy_truncate_heap(Relation onerel, LVRelStats *vacrelstats) /* might as well use the latest news when we update pg_class stats */ vacrelstats->rel_pages = new_rel_pages; UnlockRelation(onerel, AccessExclusiveLock); - return false; + return; } /* @@ -1044,34 +1030,22 @@ lazy_truncate_heap(Relation onerel, LVRelStats *vacrelstats) { /* can't do anything after all */ UnlockRelation(onerel, AccessExclusiveLock); - return false; + return; } /* - * Prevent cancel/die interrupts from now till commit. Once we have - * truncated, it is essential that we send the sinval message before - * releasing exclusive lock on the relation; both of which will - * happen during commit. Other backends must receive the sinval - * message to reset their rd_targblock values before they can safely - * write to the table again. While we can't positively guarantee - * no error before commit, we can at least prevent cancel interrupts. - * - * XXX it would be better if we had a way to send the inval message - * nontransactionally; an error after the truncate will mean that the - * message is lost. Note however that turning this all into a critical - * section would not be an improvement. Making it critical would mean - * that an error forces PANIC, whereas losing the sinval will at worst - * cause unexpected nonfatal errors in other sessions. + * Okay to truncate. */ - HOLD_INTERRUPTS(); - - /* force relcache inval so all backends reset their rd_targblock */ - CacheInvalidateRelcache(onerel); + RelationTruncate(onerel, new_rel_pages); /* - * Okay to truncate. Do as little as possible between here and commit. + * We can release the exclusive lock as soon as we have truncated. Other + * backends can't safely access the relation until they have processed the + * smgr invalidation that smgrtruncate sent out ... but that should happen + * as part of standard invalidation processing once they acquire lock on + * the relation. */ - RelationTruncate(onerel, new_rel_pages); + UnlockRelation(onerel, AccessExclusiveLock); /* update statistics */ vacrelstats->rel_pages = new_rel_pages; @@ -1083,8 +1057,6 @@ lazy_truncate_heap(Relation onerel, LVRelStats *vacrelstats) old_rel_pages, new_rel_pages), errdetail("%s.", pg_rusage_show(&ru0)))); - - return true; /* interrupts are held off */ } /* |