Re: Problems with VACUUM and "dead row versions cannot be removed yet"

Nolan Cafferky  writes:
> I've got an admin_sessions table on a postgres 8.0.8 server that gets 
> updated frequently, with about 30 live rows at any given time.  We 
> VACUUM the table nightly, which has served us with no problems for quite 
> some time.  Well, this morning we noticed some seriously slow queries 
> against the table, and VACUUM VERBOSE reported around 84,000 rows that 
> were "nonremovable".  Same results with VACUUM FULL ANALYZE VERBOSE.

Lots of nonremovable rows means you've got some really old open
transactions.  Look into pg_stat_activity or pg_locks to help find
the culprit.

			regards, tom lane