Re: Physical sites handling large data

Hmmm...

Using the bigmem kernel and RH7.3, we were able to set Postgresql shared
memory to 3.2Gigs (out of 6GB Ram). Does this mean that Postgresql will
only use the first 2Gigs?

Our settings are:

shmmax = 3192000000
shared_buffers = 38500

ipcs output:
0x0052e2c1 98304      postgres  600        324018176  51

- Ericson Smith
eric@did-it.com

On Sun, 2002-09-15 at 11:01, Tom Lane wrote:
> "Shridhar Daithankar" <shridhar_daithankar@persistent.co.in> writes:
> > On this topic, say I decide to devote 8GB to postgres that means 1048576
> > buffers for 8K page size. Need I push available number of shared memory
> > segments beyond this value? Can I tweak size of page? If I can would it help
> > for such an installation?
>
> I do not believe you can push the shared memory size past 2GB, or about
> 250K buffers, because the size calculations for it are done in "int"
> arithmetic.  Of course, this could be fixed if anyone cared to do the
> legwork.  I doubt there's much point in worrying about it though.
> A larger memory is still usable, it's just that the rest of it will be
> used in the form of kernel-level disk cache not Postgres buffers.
>
>             regards, tom lane
>
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