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From: Robert Klemme <[email protected]>
To: pgsql-performance <[email protected]>
Subject: Re: Database transaction with intermittent slow responses
Date: Sat, 14 May 2016 11:47:30 +0200
Message-ID: <CAM9pMnPenVHAg0BB4vKDmGOTSyef4stOGAgYSWAwgc-EtME7Jw@mail.gmail.com> (raw)
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On Sat, May 14, 2016 at 1:11 AM, Gerardo Herzig wrote:
> Oh, so *all* the transactions are being slowed down at that point...What about CPU IO Wait% at that moment? Could be some other processes stressing the system out?

Or the database has just grown pass the size where disk caching is
efficient. Usually these are nonlinear processes, i.e. it works good
until a certain moment and then cache hit ratio decreases dramatically
because all of a sudden content starts heavily competing about space
in the cache.

> Now im thinking about hard disk issues...maybe some "smart" messages?
>
> Have some other hardware to give it a try?

Can we please see the full DDL of table and indexes?

The only additional idea I can throw up at the moment is looking at a
combined index on (primarykeyofchange, category) - maybe replacing
changehistory_idx4 - but that of course depends on the other SQL used
against that table.

Kind regards

robert

-- 
[guy, jim, charlie].each {|him| remember.him do |as, often| as.you_can
- without end}
http://blog.rubybestpractices.com/


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