From: Miguel Silva <miguel.silva@tactis.pt>
To: Merlin Moncure <mmoncure@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Query performance - normal on 9.0.4, slow from 9.0.5 onwards
Date: Mon, 02 Jan 2012 11:44:43 +0000
Message-ID: <4F0198AB.6030405@tactis.pt> (raw)
In-Reply-To: <CAHyXU0yStki+BSncowz5TZVqYXQcfm6j1i1qsHBED84a_-cpgQ@mail.gmail.com>
References: <4EFDE928.50807@tactis.pt>
<CAHyXU0yStki+BSncowz5TZVqYXQcfm6j1i1qsHBED84a_-cpgQ@mail.gmail.com>
On 30-12-2011 19:35, Merlin Moncure wrote:
> try this (curious):
> create table pos as select n from generate_series(1,32) n;
>
> and swap that for the in-query generate series call. your statistics
> in the query are completely off (not 100% sure why), so I'm thinking
> to replace that since it lies to the planner about the # rows
> returned. also the join on the array element probably isn't helping.
>
> merlin
>
Tried it. The query still takes around the same amount of time but, out
of curiosity, here's the explain analyze of it:
http://explain.depesz.com/s/MvE .
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To: pgsql-performance@postgresql.org
Cc: miguel.silva@tactis.pt, mmoncure@gmail.com
Subject: Re: Query performance - normal on 9.0.4, slow from 9.0.5 onwards
In-Reply-To: <4F0198AB.6030405@tactis.pt>
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