From: Bruce Momjian <pgman@candle.pha.pa.us>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: PostgreSQL-documentation <pgsql-docs@postgresql.org>
Subject: Re: Default shared memory SGML mention
Date: Tue, 8 May 2001 14:01:43 -0400 (EDT)
Message-ID: <200105081801.f48I1ho19055@candle.pha.pa.us> (raw)
In-Reply-To: <17050.988841325@sss.pgh.pa.us>
> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > so by my computations, we need about 700k added to the shared buffer
> > cache area. The documentation says to add 512k, not 700k.
>
> This would depend on your -N setting.
>
> A little experimentation shows that the present multiplier for -B is
> about 8350 bytes and the multiplier for -N about 14580 bytes on my
> system (HPUX), which extrapolates to a fixed base of about 250K plus
> the -B and -N contributions. In reality I believe the computation
> is somewhat nonlinear, but that's probably close enough for starters.
I have updated the SGML sources to say for default shared memory values:
250 kB + 8192 * buffers or infinity
Of course, buffers is 2 * connections by default.
--
Bruce Momjian | http://candle.pha.pa.us
pgman@candle.pha.pa.us | (610) 853-3000
+ If your life is a hard drive, | 830 Blythe Avenue
+ Christ can be your backup. | Drexel Hill, Pennsylvania 19026
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To: pgsql-docs@postgresql.org
Cc: pgman@candle.pha.pa.us, tgl@sss.pgh.pa.us
Subject: Re: Default shared memory SGML mention
In-Reply-To: <200105081801.f48I1ho19055@candle.pha.pa.us>
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