Date: Mon, 21 Oct 2013 08:05:33 -0700 (PDT)
From: sparikh <sparikh@ecotality.com>
To: pgsql-performance@postgresql.org
Message-ID: <1382367933794-5775257.post@n5.nabble.com>
In-Reply-To: <526460B7.3020008@fuzzy.cz>
References: <1381869626548-5774673.post@n5.nabble.com>
 <1382291901534-5775181.post@n5.nabble.com> <526460B7.3020008@fuzzy.cz>
Subject: Re: Hot Standby performance issue
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Stupid question - when you say that a query is fast on primary but slow 
on standby, are you referring to exactly the same query, including 
parameter values? 

Yes . It is exactly and exactly the same query with the same parameters. 
Yes, it sounds stupid  but that is what happening. Though plan says it is
18ms it runs for more than 15-20 mins and finally returns with conflict
error : " ERROR: canceling statement due to conflict with recovery "

Even the to run execute plan itself takes very long on standby. Just to get
the execute plan on standby is turning out big deal. 

Regarding IO spike, yes I can understand that if data is not available in
the memory then it has to get it from disk. But the thing is it remains
there as much time until query returns with Query conflict error.

Thanks again.


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