diff options
Diffstat (limited to 'src/backend/commands/vacuum.c')
| -rw-r--r-- | src/backend/commands/vacuum.c | 51 |
1 files changed, 24 insertions, 27 deletions
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c index c21be2f478..8c1df23d9b 100644 --- a/src/backend/commands/vacuum.c +++ b/src/backend/commands/vacuum.c @@ -13,7 +13,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/commands/vacuum.c,v 1.337 2006/07/31 20:09:00 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/commands/vacuum.c,v 1.338 2006/08/18 16:09:08 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -1042,31 +1042,12 @@ vacuum_rel(Oid relid, VacuumStmt *vacstmt, char expected_relkind) } /* - * Tell the cache replacement strategy that vacuum is causing all - * following IO - */ - StrategyHintVacuum(true); - - /* * Check for user-requested abort. Note we want this to be inside a * transaction, so xact.c doesn't issue useless WARNING. */ CHECK_FOR_INTERRUPTS(); /* - * Race condition -- if the pg_class tuple has gone away since the last - * time we saw it, we don't need to vacuum it. - */ - if (!SearchSysCacheExists(RELOID, - ObjectIdGetDatum(relid), - 0, 0, 0)) - { - StrategyHintVacuum(false); - CommitTransactionCommand(); - return; - } - - /* * Determine the type of lock we want --- hard exclusive lock for a FULL * vacuum, but just ShareUpdateExclusiveLock for concurrent vacuum. Either * way, we can be sure that no other backend is vacuuming the same table. @@ -1074,7 +1055,21 @@ vacuum_rel(Oid relid, VacuumStmt *vacstmt, char expected_relkind) lmode = vacstmt->full ? AccessExclusiveLock : ShareUpdateExclusiveLock; /* - * Open the class, get an appropriate lock on it, and check permissions. + * Open the relation and get the appropriate lock on it. + * + * There's a race condition here: the rel may have gone away since + * the last time we saw it. If so, we don't need to vacuum it. + */ + onerel = try_relation_open(relid, lmode); + + if (!onerel) + { + CommitTransactionCommand(); + return; + } + + /* + * Check permissions. * * We allow the user to vacuum a table if he is superuser, the table * owner, or the database owner (but in the latter case, only if it's not @@ -1083,8 +1078,6 @@ vacuum_rel(Oid relid, VacuumStmt *vacstmt, char expected_relkind) * Note we choose to treat permissions failure as a WARNING and keep * trying to vacuum the rest of the DB --- is this appropriate? */ - onerel = relation_open(relid, lmode); - if (!(pg_class_ownercheck(RelationGetRelid(onerel), GetUserId()) || (pg_database_ownercheck(MyDatabaseId, GetUserId()) && !onerel->rd_rel->relisshared))) { @@ -1092,7 +1085,6 @@ vacuum_rel(Oid relid, VacuumStmt *vacstmt, char expected_relkind) (errmsg("skipping \"%s\" --- only table or database owner can vacuum it", RelationGetRelationName(onerel)))); relation_close(onerel, lmode); - StrategyHintVacuum(false); CommitTransactionCommand(); return; } @@ -1107,7 +1099,6 @@ vacuum_rel(Oid relid, VacuumStmt *vacstmt, char expected_relkind) (errmsg("skipping \"%s\" --- cannot vacuum indexes, views, or special system tables", RelationGetRelationName(onerel)))); relation_close(onerel, lmode); - StrategyHintVacuum(false); CommitTransactionCommand(); return; } @@ -1122,7 +1113,6 @@ vacuum_rel(Oid relid, VacuumStmt *vacstmt, char expected_relkind) if (isOtherTempNamespace(RelationGetNamespace(onerel))) { relation_close(onerel, lmode); - StrategyHintVacuum(false); CommitTransactionCommand(); return; /* assume no long-lived data in temp tables */ } @@ -1146,6 +1136,12 @@ vacuum_rel(Oid relid, VacuumStmt *vacstmt, char expected_relkind) toast_relid = onerel->rd_rel->reltoastrelid; /* + * Tell the cache replacement strategy that vacuum is causing all + * following IO + */ + StrategyHintVacuum(true); + + /* * Do the actual work --- either FULL or "lazy" vacuum */ if (vacstmt->full) @@ -1153,13 +1149,14 @@ vacuum_rel(Oid relid, VacuumStmt *vacstmt, char expected_relkind) else lazy_vacuum_rel(onerel, vacstmt); + StrategyHintVacuum(false); + /* all done with this class, but hold lock until commit */ relation_close(onerel, NoLock); /* * Complete the transaction and free all temporary memory used. */ - StrategyHintVacuum(false); CommitTransactionCommand(); /* |