Craig James wrote: > On 4/7/10 5:47 PM, Robert Haas wrote: > > On Wed, Apr 7, 2010 at 6:56 PM, David Rees<drees76@xxxxxxxxx> wrote: > >>> max_fsm_pages = 16000000 > >>> max_fsm_relations = 625000 > >>> synchronous_commit = off > >> > >> You are playing with fire here. You should never turn this off unless > >> you do not care if your data becomes irrecoverably corrupted. > > > > That is not correct. Turning off synchronous_commit is sensible if > > you don't mind losing the last few transactions on a crash. What will > > corrupt your database is if you turn off fsync. > > A bit off the original topic, but ... > > I set it this way because I was advised that with a battery-backed > RAID controller, this was a safe setting. Is that not the case? To get good performance, you can either get a battery-backed RAID controller or risk losing a few transaction with synchronous_commit = off. If you already have a battery-backed RAID controller, there is little benefit to turning synchronous_commit off, and some major downsides (possible data loss). -- Bruce Momjian <bruce@xxxxxxxxxx> http://momjian.us EnterpriseDB http://enterprisedb.com -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
