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Re: "Slow" query or just "Bad hardware"?

From: PFC <lists(at)peufeu(dot)com>
To: "Jesper Krogh" <jesper(at)krogh(dot)cc>, pgsql-performance(at)postgresql(dot)org
Subject: Re: "Slow" query or just "Bad hardware"?
Date: 2008-03-27 16:57:06
Message-ID: (view raw, whole thread or download thread mbox)
Lists: pgsql-performance
Also, sometimes offine TOASTing is evil :
Say you have a forum, you want the posts table to be CLUSTER'ed on  
(topic_id, post_id) so displaying 1 page with 30 posts on it uses 1 seek,  
not 30 seeks. But CLUSTER doesn't touch the data that has been pushed  
offline in the toast table. So, in that case, it can pay (big time  
actually) to disable toasting, store the data inline, and benefit from  

So basically :

Data that is seldom used or used only in queries returning/examining 1 row  
bu otherwise eats cache -> push it away (toast or partition)
Data that is used very often in queries that return/examine lots of rows,  
especially if said rows are in sequence (cluster...) -> keep it inline

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Subject: Re: "Slow" query or just "Bad hardware"?
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Subject: Re: "Slow" query or just "Bad hardware"?

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