Re: Problem with joining queries. - Mailing list pgsql-performance

From Konstantinos Krikellas
Subject Re: Problem with joining queries.
Date
Msg-id 1171549707.31678.29.camel@kkrik-desktop
Whole thread Raw
In response to Re: Problem with joining queries.  (Richard Huxton <dev@archonet.com>)
List 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.Krikellas@sms.ed.ac.uk
Pnone number: +44 (0) 131 651 3769 

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