On Fri, Feb 12, 2010 at 10:40 PM, Marcin Krol <mrk...@gmail.com> wrote:
> Hello, > > The db in the application I maintain but didn't write (it obviously > makes use of PG, v 8.3), has been systematically growing in size from > about 600M to 1.6G. > > At the same time, the performance of the app has degraded significantly > (several times). > > So I've done VACUUM ANALYZE on entire db. Nothing. The db did not > decrease in size, the performance stayed the same. > > So I backed it up using pg_dump, deleted database, and recreated it from > backup. > > The size of db on disk went down to 600M, performance recovered to the > original level. > > Why that is so? I thought that VACUUM ANALYZE does everything that is > needed to optimize disk usage? > > Regards, > mk > > You need to do VACUUM FULL ANALYZE to claim the disk space, but this creates a exclusive lock on the tables. See http://www.postgresql.org/docs/8.3/static/sql-vacuum.html With regards Amitabh Kant
