On 08/29/2011 06:12 PM, Lonni J Friedman wrote:
>
> OK, I'll reduce it to 10GB and see if there's any noticable change in
> performance. thanks
>
I've never heard a report of a Linux system using more than 8GB of
shared_buffers usefully, and peak performance on systems I've tested has
sometimes been far less than that even. (I have one server that's stuck
at 512MB!) The only report of even 10GB helping came from a Solaris test.
I doubt this has anything to do with your problem, just pointing this
out as future guidance. Until there's a breakthrough in the PostgreSQL
buffer cache code, there really is no reason to give more than 8GB of
dedicated memory to the database on Linux via shared_buffers. You're
better off letting the OS do caching with it instead.
--
Greg Smith 2ndQuadrant US greg@2ndQuadrant.com Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.us