Re: 8.3rc1 Out of memory when performing update

I don't have a PostgreSQL build environment.

It is now Friday night for me. I left the alternate query running, and will find out on Monday what happened.

If I drop the fk constraint, and/or its index, would I still be affected by the leak you found?

Regards,
Stephen Denne.

________________________________

From: Tom Lane [mailto:tgl(at)sss(dot)pgh(dot)pa(dot)us]
Sent: Fri 25/01/2008 5:50 p.m.
To: Stephen Denne
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: [PERFORM] 8.3rc1 Out of memory when performing update

"Stephen Denne" <Stephen(dot)Denne(at)datamail(dot)co(dot)nz> writes:
> I altered the update statement slightly, and reran the query.
> The altered query has been running over 3 hours now,
> without using lots of memory (38M private bytes).
> 2046 temp files were created (2.54GB worth),
> which have recently changed from slowly growing in size
> to very very slowly reducing in number.

Hmm. I think what that really means is you haven't got to the part of
the query where the leak is :-(. In my attempt to reproduce this
I found that 8.3 has introduced a memory leak into the RI trigger
support, such that even if an UPDATE doesn't change the FK columns
it's still likely to leak a few dozen bytes per updated row.

Please see if the attached patch makes it better for you.

regards, tom lane

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