Re: shared_buffers > 284263 on OS X

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.

Brian Wipf