diff options
Diffstat (limited to 'src/backend/commands/vacuumlazy.c')
| -rw-r--r-- | src/backend/commands/vacuumlazy.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/src/backend/commands/vacuumlazy.c b/src/backend/commands/vacuumlazy.c index 03a0daa0d4b..67e0be9da86 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 1.121.2.1 2009/08/24 02:18:40 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/commands/vacuumlazy.c,v 1.121.2.2 2009/11/10 18:00:28 alvherre Exp $ * *------------------------------------------------------------------------- */ @@ -140,8 +140,11 @@ 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 -- caller must RESUME_INTERRUPTS() after commit if true. */ -void +bool lazy_vacuum_rel(Relation onerel, VacuumStmt *vacstmt, BufferAccessStrategy bstrategy, bool *scanned_all) { @@ -153,6 +156,7 @@ lazy_vacuum_rel(Relation onerel, VacuumStmt *vacstmt, TimestampTz starttime = 0; bool scan_all; TransactionId freezeTableLimit; + bool heldoff = false; pg_rusage_init(&ru0); @@ -194,12 +198,22 @@ lazy_vacuum_rel(Relation onerel, VacuumStmt *vacstmt, * * 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. + * + * Note that after we've truncated the heap, it's too late to abort the + * transaction; doing so would lose the sinval messages needed to tell + * the other backends about the table being shrunk. We prevent interrupts + * in that case; caller is responsible for re-enabling them after + * committing the transaction. */ possibly_freeable = vacrelstats->rel_pages - vacrelstats->nonempty_pages; if (possibly_freeable > 0 && (possibly_freeable >= REL_TRUNCATE_MINIMUM || possibly_freeable >= vacrelstats->rel_pages / REL_TRUNCATE_FRACTION)) + { + HOLD_INTERRUPTS(); + heldoff = true; lazy_truncate_heap(onerel, vacrelstats); + } /* Vacuum the Free Space Map */ FreeSpaceMapVacuum(onerel); @@ -246,6 +260,8 @@ lazy_vacuum_rel(Relation onerel, VacuumStmt *vacstmt, if (scanned_all) *scanned_all = vacrelstats->scanned_all; + + return heldoff; } |