Re: shared_buffers > 284263 on OS X

["Jim C. Nasby" <jim(at)nasby(dot)net>]

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)