Re: Tuning for mid-size server - Mailing list pgsql-performance

From Bruce Momjian
Subject Re: Tuning for mid-size server
Date
Msg-id 200312140542.hBE5gLI21410@candle.pha.pa.us
Whole thread Raw
In response to Re: Tuning for mid-size server  (Andrew Sullivan <andrew@libertyrms.info>)
Responses Re: Tuning for mid-size server
List pgsql-performance
Andrew Sullivan wrote:
> On Tue, Oct 21, 2003 at 03:11:17PM -0600, scott.marlowe wrote:
> > I think where it makes sense is when you have something like a report
> > server where the result sets may be huge, but the parellel load is load,
> > i.e. 5 or 10 users tossing around 100 Meg or more at time.
>
> In our case, we were noticing that truss showed an unbelievable
> amount of time spent by the postmaster doing open() calls to the OS
> (this was on Solaris 7).  So we thought, "Let's try a 2G buffer
> size."  2G was more than enough to hold the entire data set under
> question.  Once the buffer started to fill, even plain SELECTs
> started taking a long time.  The buffer algorithm is just not that
> clever, was my conclusion.
>
> (Standard disclaimer: not a long, controlled test.  It's just a bit
> of gossip.)

I know this is an old email, but have you tested larger shared buffers
in CVS HEAD with Jan's new cache replacement policy?

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