From: Manfred Koizar <mkoi-pg@aon.at>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-hackers@postgresql.org
Subject: Re: Correlation in cost_index()
Date: Thu, 03 Oct 2002 09:09:49 +0200
Message-ID: <3mpnpuccoukikseed1e3pedo5t1dfj64cn@4ax.com> (raw)
In-Reply-To: <29475.1033598929@sss.pgh.pa.us>
References: <n6cmpug13b9rk1srebjvhphg0lm8dou1kn@4ax.com>
<29475.1033598929@sss.pgh.pa.us>
On Wed, 02 Oct 2002 18:48:49 -0400, Tom Lane <tgl@sss.pgh.pa.us>
wrote:
>I don't think it's really a good idea to expect users to pick among
>multiple cost functions
The idea is that PG is shipped with a default representing the best of
our knowledge and users are not encouraged to change it. When a user
sends a "PG does not use my index" or "Why doesn't it scan
sequentially?" message to one of the support lists, we advise her/him
to set index_cost_algorithm to 3 (or whatever we feel appropriate) and
watch the feedback we get.
We don't risk anything, if the default is the current behaviour.
Servus
Manfred
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To: pgsql-hackers@postgresql.org
Cc: mkoi-pg@aon.at, tgl@sss.pgh.pa.us
Subject: Re: Correlation in cost_index()
In-Reply-To: <3mpnpuccoukikseed1e3pedo5t1dfj64cn@4ax.com>
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