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Message-ID: <47909577.4070704@careerjunction.co.za>
Date: Fri, 18 Jan 2008 14:03:03 +0200
From: Adrian Moisey <adrian@careerjunction.co.za>
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To: pgsql-performance@postgresql.org
Subject: Re: strange pauses
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	<4790863E.4000309@careerjunction.co.za>
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Hi

>>> If I tail the logs, I see a steady stream of functions that took 
>>> longer then 5 seconds.  But every now and then I see nothing for 3 
>>> minutes and after that a whole bunch (about 20 - 30) queries all 
>>> finishing at the same second.
>>
>> Search this list for references to "checkpoints". If you run 
>> vmstat/iostat for a bit you should see bursts of disk activity at 
>> those times.
>>
>> Counter-intuitively you probably want *more* checkpoints (with less 
>> data to write out each time), but see the list archives for 
>> discussion. Also check the manuals for some background info.
> 
> We use a lot of checkpoints in our database, we don't care about these 

We use a lot of temporary tables in our database, sorry.

> much.  We think this is causing the checkpoint to write a lot of data at 
> checkpoint time.  Can we stop this behavior ?
> 

-- 
Adrian Moisey
System Administrator | CareerJunction | Your Future Starts Here.
Web: www.careerjunction.co.za | Email: adrian@careerjunction.co.za
Phone: +27 21 686 6820 | Mobile: +27 82 858 7830 | Fax: +27 21 686 6842