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Re: Caching of Queries

From: Josh Berkus <josh(at)agliodbs(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: "Jason Coene" <jcoene(at)gotfrag(dot)com>,"'Mr Pink'" <mr_pink_is_the_only_pro(at)yahoo(dot)com>,"'Scott Kirkwood'" <scottakirkwood(at)gmail(dot)com>,pgsql-performance(at)postgresql(dot)org
Subject: Re: Caching of Queries
Date: 2004-09-23 18:56:31
Message-ID: 200409231156.31450.josh@agliodbs.com (view raw or flat)
Thread:
Lists: pgsql-performance
Tom,

> I think you are probably looking at the same problem previously reported
> by Josh Berkus among others.  Does the rate of context swaps shown by
> vmstat go through the roof when this happens?  If you strace or ktrace
> one of the backends, do you see lots of semop()s and little else?

That would be interesting.   Previously we've only demonstrated the problem on 
long-running queries, but I suppose it could also affect massive concurrent 
query access.

-- 
Josh Berkus
Aglio Database Solutions
San Francisco

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