Horton

Re: [HACKERS] Changing the default configuration (was Re:

Christopher Kings-Lynne <chriskl@familyhealth.com.au>

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From: "Christopher Kings-Lynne" <chriskl@familyhealth.com.au>
To: "Tom Lane" <tgl@sss.pgh.pa.us>, "Peter Eisentraut" <peter_e@gmx.net>
Cc: "Merlin Moncure" <merlin.moncure@rcsonline.com>, "PostgresSQL Hackers Mailing List" <pgsql-hackers@postgresql.org>, <pgsql-advocacy@postgresql.org>
Date: 2003-02-12T05:32:41Z
Lists: pgsql-hackers, pgsql-performance 
> >> We could retarget to try to stay under SHMMAX=4M, which I think is
> >> the next boundary that's significant in terms of real-world platforms
> >> (isn't that the default SHMMAX on some BSDen?).  That would allow us
> >> 350 or so shared_buffers, which is better, but still not really a
> >> serious choice for production work.
>
> > What is a serious choice for production work?
>
> Well, as I commented later in that mail, I feel that 1000 buffers is
> a reasonable choice --- but I have to admit that I have no hard data
> to back up that feeling.  Perhaps we should take this to the
> pgsql-perform list and argue about reasonable choices.

Damn. Another list I have to subscribe to!

The results I just posted indicate that 1000 buffers is really quite bad
performance comaped to 4000, perhaps up to 100 TPS for selects and 30 TPS
for TPC-B.

Still, that 1000 is in itself vastly better than 64!!

Chris