Re: Mapping a database completly into Memory

Franco Bruno Borghesi <franco@akyasociados.com.ar> writes:
> wouldn't also increasing shared_buffers to 64 or 128 MB be a good
> performance improvement? This way, pages belonging to heavily used
> indexes would be already cached by the database itself.

Not necessarily.  The trouble with large shared_buffers settings is you
end up with lots of pages being doubly cached (both in PG's buffers and
in the kernel's disk cache), thus wasting RAM.  If we had a portable way
of preventing the kernel from caching the same page, it would make more
sense to run with large shared_buffers.

            regards, tom lane