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Re: Default cost variables in postgresql.conf

From: Andrew Sullivan <andrew(at)libertyrms(dot)info>
To: PostgreSQL Mailing List <pgsql-performance(at)postgresql(dot)org>
Subject: Re: Default cost variables in postgresql.conf
Date: 2002-10-21 14:16:21
Message-ID: (view raw, whole thread or download thread mbox)
Lists: pgsql-performance
On Mon, Oct 21, 2002 at 12:04:58AM -0700, Ludwig Lim wrote:
> Hi:
>   Are the "cost" variables (e.g.
> random_page_cost,cpu_tuple_cost,cpu_index_tuple_cost)
> in postgresql.conf optimal for a particular set of
> platform / hardware requirements? (i.e. the configs

Not exactly.  They're best guesses.  If you check the admin guide,
you'll see that there's a note about these which says that there is
not a well-defined method for calculating these things, so you are
encouraged to experiment and share your findings.  They _are_ known
to be conservative defaults, like everything else in the system.


Andrew Sullivan                         204-4141 Yonge Street
Liberty RMS                           Toronto, Ontario Canada
<andrew(at)libertyrms(dot)info>                              M2P 2A8
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