diff options
Diffstat (limited to 'src/backend/commands/vacuum.c')
| -rw-r--r-- | src/backend/commands/vacuum.c | 52 |
1 files changed, 37 insertions, 15 deletions
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c index d0ccf310cc4..c818d8f9667 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 1.300 2005/02/15 03:50:07 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/commands/vacuum.c,v 1.301 2005/02/20 02:21:34 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -32,6 +32,7 @@ #include "catalog/namespace.h" #include "catalog/pg_database.h" #include "catalog/pg_index.h" +#include "commands/dbcommands.h" #include "commands/vacuum.h" #include "executor/executor.h" #include "miscadmin.h" @@ -761,8 +762,13 @@ vac_update_dbstats(Oid dbid, * * Scan pg_database to determine the system-wide oldest datvacuumxid, * and use it to truncate the transaction commit log (pg_clog). - * Also generate a warning if the system-wide oldest datfrozenxid - * seems to be in danger of wrapping around. + * Also update the XID wrap limit point maintained by varsup.c. + * + * We also generate a warning if the system-wide oldest datfrozenxid + * seems to be in danger of wrapping around. This is a long-in-advance + * warning; if we start getting uncomfortably close, GetNewTransactionId + * will generate more-annoying warnings, and ultimately refuse to issue + * any more new XIDs. * * The passed XIDs are simply the ones I just wrote into my pg_database * entry. They're used to initialize the "min" calculations. @@ -778,10 +784,17 @@ vac_truncate_clog(TransactionId vacuumXID, TransactionId frozenXID) HeapScanDesc scan; HeapTuple tuple; int32 age; + NameData oldest_datname; bool vacuumAlreadyWrapped = false; bool frozenAlreadyWrapped = false; + /* init oldest_datname to sync with my frozenXID */ + namestrcpy(&oldest_datname, get_database_name(MyDatabaseId)); + /* + * Note: the "already wrapped" cases should now be impossible due to the + * defenses in GetNewTransactionId, but we keep them anyway. + */ relation = heap_openr(DatabaseRelationName, AccessShareLock); scan = heap_beginscan(relation, SnapshotNow, 0, NULL); @@ -807,7 +820,10 @@ vac_truncate_clog(TransactionId vacuumXID, TransactionId frozenXID) if (TransactionIdPrecedes(myXID, dbform->datfrozenxid)) frozenAlreadyWrapped = true; else if (TransactionIdPrecedes(dbform->datfrozenxid, frozenXID)) + { frozenXID = dbform->datfrozenxid; + namecpy(&oldest_datname, &dbform->datname); + } } } @@ -830,24 +846,30 @@ vac_truncate_clog(TransactionId vacuumXID, TransactionId frozenXID) /* Truncate CLOG to the oldest vacuumxid */ TruncateCLOG(vacuumXID); - /* Give warning about impending wraparound problems */ + /* + * Do not update varsup.c if we seem to have suffered wraparound + * already; the computed XID might be bogus. + */ if (frozenAlreadyWrapped) { ereport(WARNING, (errmsg("some databases have not been vacuumed in over 1 billion transactions"), errhint("Better vacuum them soon, or you may have a wraparound failure."))); + return; } - else - { - age = (int32) (myXID - frozenXID); - if (age > (int32) ((MaxTransactionId >> 3) * 3)) - ereport(WARNING, - (errmsg("some databases have not been vacuumed in %d transactions", - age), - errhint("Better vacuum them within %d transactions, " - "or you may have a wraparound failure.", - (int32) (MaxTransactionId >> 1) - age))); - } + + /* Update the wrap limit for GetNewTransactionId */ + SetTransactionIdLimit(frozenXID, &oldest_datname); + + /* Give warning about impending wraparound problems */ + age = (int32) (myXID - frozenXID); + if (age > (int32) ((MaxTransactionId >> 3) * 3)) + ereport(WARNING, + (errmsg("database \"%s\" must be vacuumed within %u transactions", + NameStr(oldest_datname), + (MaxTransactionId >> 1) - age), + errhint("To avoid a database shutdown, execute a full-database VACUUM in \"%s\".", + NameStr(oldest_datname)))); } |