On Fri, May 29, 2009 at 1:30 PM, Dave Dutcher <d...@tridecap.com> wrote:
> > From: Anne Rosset > > Subject: Re: [PERFORM] Unexpected query plan results > > > > > > > > Thank Dave. We are using postgresql-server-8.2.4-1PGDG and > > have work-mem set to 20MB. > > What value would you advise? > > thanks, > > > > Anne > > > Work-mem is kind of tricky because the right setting depends on how much > ram > your machine has, is the machine dedicated to postgres, and how many > simultaneous connections you have. If this is a test server, and not used > in production, you could just play around with the setting and see if your > query gets any faster. Right, the trick to remember is that you could possibly end up in a scenario where you have max_connections * work_mem being used just for sorting / joins and the rest of your memory will be swapped, so be careful not to push too high. Also, work_mem is not going to be fully allocated at fork time, it'll only use up to that much as needed. --Scott > > Here are the docs on work mem > > > http://www.postgresql.org/docs/8.2/interactive/runtime-config-resource.html# > RUNTIME-CONFIG-RESOURCE-MEMORY > > > -- > Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-performance >
