Date: Tue, 4 Oct 2011 14:55:36 +0200
From: hubert depesz lubaczewski <depesz@depesz.com>
To: "Soporte @ TEKSOL S.A." <soporte@teksol.com.ar>
Cc: pgsql-performance@postgresql.org
Subject: Re: pkey is not used on productive database
Message-ID: <20111004125536.GA21733@depesz.com>
Reply-To: depesz@depesz.com
References: <014c01cc81f4$a774e140$f65ea3c0$@teksol.com.ar>
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On Mon, Oct 03, 2011 at 02:48:10PM -0300, Soporte @ TEKSOL S.A. wrote:
> Hi, 
> 
>  
> 
> I need help to understand the issue on a productive database for a select
> that takes more time than expected.
> 
>  
> 
> 1-      On a development database I ran the query (select) and I can see on
> Explain Analyze pgAdmin use all the indexes and primary keys defined. Dev db
> has almost 10% of productive data.
> 
> 2-      On productive database the same query on Explain Analyze from
> pgAdmin shows a diferent planning, not using a pkey index and instead uses
> the progressive scan on a million of rows. I can see Primary key is defined
> for the table on pgAdmin.
> 
>  
> 
> What could be the issue on a productive for not use the pkey index for the
> SELECT?

general answer:
http://www.depesz.com/index.php/2010/09/09/why-is-my-index-not-being-used/

but for more details, we'd need to see the query and \d of the table.

Best regards,

depesz

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