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have been replaced by FrozenTransactionId.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.

1 files changed, 5 insertions, 5 deletions

diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h
index fed481971d2..5808a581cc5 100644
--- a/src/include/commands/vacuum.h
+++ b/src/include/commands/vacuum.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/commands/vacuum.h,v 1.67 2006/07/13 18:01:02 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/commands/vacuum.h,v 1.68 2006/11/05 22:42:10 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -104,8 +104,9 @@ typedef struct VacAttrStats
 } VacAttrStats;
 
 
-/* Default statistics target (GUC parameter) */
+/* GUC parameters */
 extern DLLIMPORT int default_statistics_target; /* DLLIMPORT for PostGIS */
+extern int	vacuum_freeze_min_age;
 
 
 /* in commands/vacuum.c */
@@ -117,14 +118,13 @@ extern void vac_update_relstats(Oid relid,
 					BlockNumber num_pages,
 					double num_tuples,
 					bool hasindex,
-					TransactionId minxid,
-					TransactionId vacuumxid);
+					TransactionId frozenxid);
 extern void vacuum_set_xid_limits(VacuumStmt *vacstmt, bool sharedRel,
 					  TransactionId *oldestXmin,
 					  TransactionId *freezeLimit);
+extern void vac_update_datfrozenxid(void);
 extern bool vac_is_partial_index(Relation indrel);
 extern void vacuum_delay_point(void);
-extern TransactionId vactuple_get_minxid(HeapTuple tuple);
 
 /* in commands/vacuumlazy.c */
 extern void lazy_vacuum_rel(Relation onerel, VacuumStmt *vacstmt);