wickro <robwickert@gmail.com> writes:
> I have a largish table (> 8GB). I'm doing a very simple single group
> by on. I am the only user of this database. If I set work mem to
> anything under 2GB (e.g. 1900MB) the postmaster process stops at that
> value while it's peforming it's group by. There is only one hash
> operation so that is what I would expect. But anything larger and it
> eats up all memory until it can't get anymore (around 7.5GB on a 8GB
> machine). Has anyone experienced anything of this sort before.
It's possible that you've found a bug, but you have not provided nearly
enough information to let anyone reproduce it for investigation.
What Postgres version is this exactly? Is it a 32- or 64-bit build?
What is the exact query you're executing, and what does EXPLAIN show
as its plan?
regards, tom lane