The following bug has been logged online: Bug reference: 5946 Logged by: Maxim Boguk Email address: maxim.bo...@gmail.com PostgreSQL version: 8.4 Operating system: Linux Description: Long exclusive lock taken by vacuum (not full) Details:
>From documentation I know that vacuum (without full) can truncate empty pages from end of a relation if they are free and vacuum successfully grabed exclusive lock for short time. However, I wasn't ready to learn that 'short exclusive lock' can be 10-20 minutes in some cases. In my case vacuum tried to truncate last 10-15GB from 100Gb relation, and each time (3) it was cost 10+ minutes of service downtime (because that table was completely locked). Is that correct behaviour? Are here any way to speedup that process or at least allow read-only queries during that time? PS: no exessive disk IO observed during that 10+ min locks. -- Sent via pgsql-bugs mailing list (pgsql-bugs@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-bugs
