Message-ID: <50FDE039.3030601@dunslane.net>
Date: Mon, 21 Jan 2013 19:41:29 -0500
From: Andrew Dunstan <andrew@dunslane.net>
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To: rudi <rudolone@gmail.com>
CC: pgsql-performance@postgresql.org
Subject: Re: High CPU usage after partitioning
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On 01/21/2013 10:05 AM, rudi wrote:
> Hello,
>
> I'm running postgresl 9.0. After partitioning a big table, CPU usage 
> raised from average 5-10% to average 70-80%.
>
> - the table contains about 20.000.000 rows
> - partitions are selected using a trigger, based on an indexed field, 
> a date (IF date_taken >= x AND date_taken < y)
> - I created 5 partitions, the 2012 one now contains most of the rows. 
> The 2013 partition is the "live" partition, mostly insert, a few 
> select based on the above indexed field. The 2013, 2014, 2015 
> partitions are empty
> - constraint execution is on.
> I have 2 weeks CPU usage reports and the pattern definately changed 
> after I made the partitions. Any idea?
>
>

Well, the first question that comes to my mind is whether it's the 
inserts that are causing the load or the reads. If it's the inserts then 
you should show us the whole trigger. Does it by any chance use 'execute'?

cheers

andrew


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