From: Tom Lane <tgl@sss.pgh.pa.us>
To: Alex Stapleton <alexs@advfn.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: random_page_cost = 1?
Date: Thu, 09 Jun 2005 12:55:22 -0400
Message-ID: <14199.1118336122@sss.pgh.pa.us> (raw)
In-Reply-To: <E272DAB0-E99F-45E2-9461-99E0FD40F2AC@advfn.com>
References: <E272DAB0-E99F-45E2-9461-99E0FD40F2AC@advfn.com>
Alex Stapleton <alexs@advfn.com> writes:
> Is this advisable?
Only if your database is small enough that you expect it to remain fully
cached in RAM. In that case random_page_cost = 1 does in fact describe
the performance you expect Postgres to see.
People occasionally use values for random_page_cost that are much
smaller than physical reality would suggest, but I think this is mainly
a workaround for deficiencies elsewhere in the planner cost models.
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, alexs@advfn.com
Subject: Re: random_page_cost = 1?
In-Reply-To: <14199.1118336122@sss.pgh.pa.us>
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