Work around deadlock problems with VACUUM FULL/CLUSTER on system catalogs,

as per my recent proposal.

First, teach IndexBuildHeapScan to not wait for INSERT_IN_PROGRESS or
DELETE_IN_PROGRESS tuples to commit unless the index build is checking
uniqueness/exclusion constraints.  If it isn't, there's no harm in just
indexing the in-doubt tuple.

Second, modify VACUUM FULL/CLUSTER to suppress reverifying
uniqueness/exclusion constraint properties while rebuilding indexes of
the target relation.  This is reasonable because these commands aren't
meant to deal with corrupted-data situations.  Constraint properties
will still be rechecked when an index is rebuilt by a REINDEX command.

This gets us out of the problem that new-style VACUUM FULL would often
wait for other transactions while holding exclusive lock on a system
catalog, leading to probable deadlock because those other transactions
need to look at the catalogs too.  Although the real ultimate cause of
the problem is a debatable choice to release locks early after modifying
system catalogs, changing that choice would require pretty serious
analysis and is not something to be undertaken lightly or on a tight
schedule.  The present patch fixes the problem in a fairly reasonable
way and should also improve the speed of VACUUM FULL/CLUSTER a little bit.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 7e6be57ee82..b79723a777d 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/indexcmds.c,v 1.191 2010/02/07 20:48:10 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/indexcmds.c,v 1.192 2010/02/07 22:40:33 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1588,7 +1588,7 @@ ReindexIndex(RangeVar *indexRelation)
 
 	ReleaseSysCache(tuple);
 
-	reindex_index(indOid);
+	reindex_index(indOid, false);
 }
 
 /*