Re: shared_buffers > 284263 on OS X

On Mon, Nov 27, 2006 at 07:23:47AM +0000, Brian Wipf wrote:
> On 26-Nov-06, at 11:25 PM, Jim C. Nasby wrote:
> >On Sat, Nov 18, 2006 at 08:13:26PM -0700, Brian Wipf wrote:
> >>It certainly is unfortunate if Guido's right and this is an upper
> >>limit for OS X. The performance benefit of having high shared_buffers
> >>on our mostly read database is remarkable.
> >
> >Got any data about that you can share? People have been wondering
> >about
> >cases where drastically increasing shared_buffers makes a difference.
>
> Unfortunately, there are more differences than just the
> shared_buffers setting in production right now; it's a completely
> different set up, so the numbers I have to compare against aren't
> particularly useful.
>
> When I get the chance, I will try to post data that shows the benefit
> of having a higher value of shared_buffers for our usage pattern
> (with all other settings being constant -- well, except maybe
> effective_cache_size). Basically, in our current configuration, we
> can cache all of the data we care about 99% of the time in about 3GB
> of shared_buffers. Having shared_buffers set to 512MB as it was
> originally, we were needlessly going to disk all of the time.

Disk or to the kernel cache?
--
Jim Nasby jim(at)nasby(dot)net
EnterpriseDB http://enterprisedb.com 512.569.9461 (cell)