From: Tomas Vondra <tomas.vondra@2ndquadrant.com>
To: Ancoron Luciferis <ancoron.luciferis@googlemail.com>
Cc: pgsql-performance@lists.postgresql.org
Subject: Re: Custom opclass for column statistics?
Date: Sat, 6 Jul 2019 15:38:58 +0200
Message-ID: <20190706133858.n7lj4wrte6ulcvk3@development> (raw)
In-Reply-To: <b0590dd1-5bfb-ad62-c4d0-a7057c04a68b@googlemail.com>
References: <b0590dd1-5bfb-ad62-c4d0-a7057c04a68b@googlemail.com>
On Sat, Jul 06, 2019 at 11:02:27AM +0200, Ancoron Luciferis wrote:
>Hi,
>
>I've been wondering whether it is possible somehow to have the standard
>column statistics to respect a certain operator class?
>
>The reason why I am asking for this is that I have a UUID column with a
>unique index at it using a custom operator class which implies a
>different sort order than for the default UUID operator class.
>
>This results into planner mistakes when determining whether to use the
>index for row selection or not. Too often it falls back into sequential
>scan due to this.
>
Can you share an example demonstrating the issue?
regards
--
Tomas Vondra http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
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To: pgsql-performance@postgresql.org
Cc: tomas.vondra@2ndquadrant.com, ancoron.luciferis@googlemail.com, pgsql-performance@lists.postgresql.org
Subject: Re: Custom opclass for column statistics?
In-Reply-To: <20190706133858.n7lj4wrte6ulcvk3@development>
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