Re: Default setting for enable_hashagg_disk

On Mon, 13 Jul 2020 at 23:51, Peter Eisentraut
<peter(dot)eisentraut(at)2ndquadrant(dot)com> wrote:
> I have an anecdote that might be related to this discussion.
>
> I was running an unrelated benchmark suite. With PostgreSQL 12, one
> query ran out of memory. With PostgreSQL 13, the same query instead ran
> out of disk space. I bisected this to the introduction of disk-based
> hash aggregation. Of course, the very point of that feature is to
> eliminate the out of memory and make use of disk space instead. But
> running out of disk space is likely to be a worse experience than
> running out of memory. Also, while it's relatively easy to limit memory
> use both in PostgreSQL and in the kernel, it is difficult or impossible
> to limit disk space use in a similar way.

Isn't that what temp_file_limit is for?

David