Manipulating disk cache (buf) settings

Vivek Khera vivek at
Tue May 24 07:14:48 PDT 2005

On May 23, 2005, at 7:29 PM, John-Mark Gurney wrote:

> Vivek Khera wrote this message on Mon, May 23, 2005 at 17:17 -0400:
>> Cool... So what would you recommend telling an application like
>> Postgres what the cache size is?  All of RAM?  That seems unlikely
>> given much of the ram is used for other things.  Is there no upper
>> bound in how much RAM will be used for the cache?
> I'm not familar host Postgres uses the cache number to change it's
> behavior, but I would say choose a responable amount of memory that
> you expect to regularly have available on the system...   If you are
> only using it for db, and a few other small processes, 512meg less
> than ram is probably reasonable...

Thanks.  Since PG also uses a bunch of RAM for internal ops like  
sorting and such, I suspect telling it that 50% of RAM is available  
for cache will be good.  Testing theory now... :-)

Vivek Khera, Ph.D.
+1-301-869-4449 x806

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