Re: FW: [ADMIN] Shared_buffers and kernel parameters, tuning

Rune,

> > shared_buffers = 117248 (shmmax / 2 / 1024 / 8 ) This I got from this
> > forum.
> > Does this sound right or am I totally out of bounds here? I have, as said

Out of bounds, through no fault of your own .... I'm still working on
documentation for this.  However, let me qoute the upcoming supplimentary
docs:

SHARED_BUFFERS
Sets the size of Postgres' memory buffer where queries are held before being
fed into the Kernel buffer of the host system.  It's very important to
remember that this is only a holding area, and not the total memory available
for the server.  As such, resist the urge to set this number to a large
portion of your RAM, as this will actually degrade performance on many OSes.
Members of the pgsql-performance mailing list have found useful values in the
range of 1000-6000, depending on available RAM, database size, and number of
concurrent queries. No one has yet reported positive results for any number
over 6000.

--
Josh Berkus
Aglio Database Solutions
San Francisco