On Wed, May 7, 2014 at 11:38 AM, Andres Freund <andres@2ndquadrant.com> wrote:
>> *) raising shared buffers does not 'give more memory to postgres for
>> caching' -- it can only reduce it via double paging
>
> That's absolutely not a necessary consequence. If pages are in s_b for a
> while the OS will be perfectly happy to throw them away.
The biggest problem with double buffering is not that it wastes
memory. Rather, it's that it wastes memory bandwidth. I think that
lessening that problem will be the major benefit of making larger
shared_buffers settings practical.
--
Peter Geoghegan
