From 48188e1621bb6711e7d092bee48523b18cd80177 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Sun, 5 Nov 2006 22:42:10 +0000 Subject: Fix recently-understood problems with handling of XID freezing, particularly in PITR scenarios. We now WAL-log the replacement of old XIDs with FrozenTransactionId, so that such replacement is guaranteed to propagate to PITR slave databases. Also, rather than relying on hint-bit updates to be preserved, pg_clog is not truncated until all instances of an XID are known to have been replaced by FrozenTransactionId. Add new GUC variables and pg_autovacuum columns to allow management of the freezing policy, so that users can trade off the size of pg_clog against the amount of freezing work done. Revise the already-existing code that forces autovacuum of tables approaching the wraparound point to make it more bulletproof; also, revise the autovacuum logic so that anti-wraparound vacuuming is done per-table rather than per-database. initdb forced because of changes in pg_class, pg_database, and pg_autovacuum catalogs. Heikki Linnakangas, Simon Riggs, and Tom Lane. --- src/backend/access/transam/xact.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'src/backend/access/transam/xact.c') diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 8e1724989cb..3c6e2ebf5cd 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -10,7 +10,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/access/transam/xact.c,v 1.227 2006/10/04 00:29:49 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/access/transam/xact.c,v 1.228 2006/11/05 22:42:07 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -468,8 +468,12 @@ TransactionIdIsCurrentTransactionId(TransactionId xid) * is what we need during bootstrap. (Bootstrap mode only inserts tuples, * it never updates or deletes them, so all tuples can be presumed good * immediately.) + * + * Likewise, InvalidTransactionId and FrozenTransactionId are certainly + * not my transaction ID, so we can just return "false" immediately for + * any non-normal XID. */ - if (xid == BootstrapTransactionId) + if (!TransactionIdIsNormal(xid)) return false; /* -- cgit v1.2.3