From: Jan Dittmer <jdi@l4x.org>
To: Scott Marlowe <scott.marlowe@gmail.com>
Cc: Bruno Rodrigues Siqueira <bruno@ravnus.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: select on 1milion register = 6s
Date: Wed, 01 Aug 2007 19:37:11 +0200
Message-ID: <46B0C4C7.7000202@l4x.org> (raw)
In-Reply-To: <dcc563d10707282151m7a2de11ex5f593cfc19b98095@mail.gmail.com>
References: <46ABA01E.8000802@emolecules.com>
<002001c7d153$944f3c60$e900a8c0@brunolaptop>
<dcc563d10707282151m7a2de11ex5f593cfc19b98095@mail.gmail.com>
Scott Marlowe wrote:
>> random_page_cost = 1 # units are one sequential page
>> fetch
>
> Seldom if ever is it a good idea to bonk the planner on the head with
> random_page_cost=1. setting it to 1.2 ot 1.4 is low enough, but 1.4
> to 2.0 is more realistic.
Which is probably the reason why the planner thinks a seq scan is
faster than an index scan...
Jan
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To: pgsql-performance@postgresql.org
Cc: jdi@l4x.org, scott.marlowe@gmail.com, bruno@ravnus.com
Subject: Re: select on 1milion register = 6s
In-Reply-To: <46B0C4C7.7000202@l4x.org>
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