Re: Odd out of memory problem.

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Greg Stark <stark@mit.edu>
Cc: Andrew Dunstan <andrew@dunslane.net>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2012-03-26T17:15:47Z
Lists: pgsql-hackers
Greg Stark <stark@mit.edu> writes:
> I have a sketch for how to handle spilling hash aggregates to disk in
> my head. I'm not sure if it's worth the amount of complexity it would
> require but I'll poke around a bit and see if it works out well.

It'd be awfully nice if those could spill to disk.  I think that
currently that's the only plan type where a misestimate can lead to
hard failure rather than just slower-than-you'd-like.  Which is not
nice considering that the estimates are necessarily just estimates.

Could you give us a brain dump on the sketch?  I've never seen how to
do it without unreasonable overhead.

			regards, tom lane