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authorTom Lane <tgl@sss.pgh.pa.us>2006-11-05 22:42:10 +0000
committerTom Lane <tgl@sss.pgh.pa.us>2006-11-05 22:42:10 +0000
commit48188e1621bb6711e7d092bee48523b18cd80177 (patch)
tree524459ab58f8740a23efa7b7b521833646c678ba /src/backend/access/transam/xact.c
parent10c70b86023001dc6d9028737afc97850b86e58f (diff)
downloadpostgresql-48188e1621bb6711e7d092bee48523b18cd80177.tar.gz
postgresql-48188e1621bb6711e7d092bee48523b18cd80177.zip
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relying on hint-bit updates to be preserved, pg_clog is not truncated until all instances of an XID are known to have been replaced by FrozenTransactionId.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.
Diffstat (limited to 'src/backend/access/transam/xact.c')
-rw-r--r--src/backend/access/transam/xact.c8
1 files changed, 6 insertions, 2 deletions
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;
/*