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Re: Problem with joining queries.

From: Konstantinos Krikellas <K(dot)Krikellas(at)sms(dot)ed(dot)ac(dot)uk>
To: Richard Huxton <dev(at)archonet(dot)com>
Cc: pgsql-performance(at)postgresql(dot)org, Stratis Viglas <sviglas(at)inf(dot)ed(dot)ac(dot)uk>
Subject: Re: Problem with joining queries.
Date: 2007-02-15 14:28:27
Message-ID: 1171549707.31678.29.camel@kkrik-desktop (view raw, whole thread or download thread mbox)
Lists: pgsql-performance
> Not happening here (8.2.x, output redirected using "\o /dev/null") - are 
> you sure it's not psql (or whatever client) that's using up your memory, 
> as it tries to build the entire result set before sending it to 
> /dev/null? Don't forget, you've got 5 copies of the columns so that 
> would be ~ 700MB.
> If it is the backend, you'll need to give some of the tuning parameters 
> you're using, since it works here on my much smaller dev server (1GB RAM 
> and plenty of other stuff using it).

You are absolutely right about the result size.

I tried the '\o /dev/null' and worked, I had not realised the client is
buffering the final result. 
Instead, I used to execute the command 'psql < query.sql > /dev/null',
so the psql process consumed all the available memory.

Thank you very much for your immediate and felicitous response.

Kind regards,  
Konstantinos Krikellas
PhD student, Database Group
University of Edinburgh
Email: K(dot)Krikellas(at)sms(dot)ed(dot)ac(dot)uk
Pnone number: +44 (0) 131 651 3769 

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