From: Vlad Arkhipov <arhipov@dc.baikal.ru>
To: Albe Laurenz <laurenz.albe@wien.gv.at>
Cc: pgsql-performance@postgresql.org
Subject: Re: Optimizer's issue
Date: Thu, 24 Apr 2008 18:47:37 +0900
Message-ID: <48105739.30900@dc.baikal.ru> (raw)
In-Reply-To: <D960CB61B694CF459DCFB4B0128514C202043E0F@exadv11.host.magwien.gv.at>
References: <480FDF0E.3000909@dc.baikal.ru>
<D960CB61B694CF459DCFB4B0128514C202043E0F@exadv11.host.magwien.gv.at>
Albe Laurenz пишет:
> Vlad Arkhipov wrote:
>
>> I found strange issue in very simple query.
>>
>
> You forgot to mention what your problem is.
>
> Yours,
> Laurenz Albe
>
It was written below in my first post:
"These queries are part of big query and optimizer put them on the leaf
of query tree, so rows miscount causes a real problem. "
actual rows count for the first query is 294, estimate - 11; for the
second -- 283 and 0. Postgres tries to use nested loops when it should
use merge/hash join and vice versa.
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To: pgsql-performance@postgresql.org
Cc: arhipov@dc.baikal.ru, laurenz.albe@wien.gv.at
Subject: Re: Optimizer's issue
In-Reply-To: <48105739.30900@dc.baikal.ru>
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