| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Stephen Frost <sfrost(at)snowman(dot)net> |
| Cc: | Peter Geoghegan <pg(at)bowt(dot)ie>, Jeff Davis <pgsql(at)j-davis(dot)com>, Alvaro Herrera <alvherre(at)2ndquadrant(dot)com>, Andres Freund <andres(at)anarazel(dot)de>, Bruce Momjian <bruce(at)momjian(dot)us>, Robert Haas <robertmhaas(at)gmail(dot)com>, David Rowley <dgrowleyml(at)gmail(dot)com>, Justin Pryzby <pryzby(at)telsasoft(dot)com>, Melanie Plageman <melanieplageman(at)gmail(dot)com>, Tomas Vondra <tomas(dot)vondra(at)2ndquadrant(dot)com>, "pgsql-hackers(at)postgresql(dot)org" <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: Default setting for enable_hashagg_disk |
| Date: | 2020-07-10 21:59:59 |
| Message-ID: | 2165606.1594418399@sss.pgh.pa.us |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-docs pgsql-hackers |
Stephen Frost <sfrost(at)snowman(dot)net> writes:
> I don't see hash_mem as being any kind of proper fix- it's just punting
> to the user saying "we can't figure this out, how about you do it" and,
> worse, it's in conflict with how we already ask the user that question.
> Turning it into a multiplier doesn't change that either.
Have you got a better proposal that is reasonably implementable for v13?
(I do not accept the argument that "do nothing" is a better proposal.)
I agree that hash_mem is a stopgap, whether it's a multiplier or no,
but at this point it seems difficult to avoid inventing a stopgap.
Getting rid of the process-global work_mem setting is a research project,
and one I wouldn't even count on having results from for v14. In the
meantime, it seems dead certain that there are applications for which
the current behavior will be problematic. hash_mem seems like a cleaner
and more useful stopgap than the "escape hatch" approach, at least to me.
regards, tom lane
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Peter Geoghegan | 2020-07-10 23:10:53 | Re: Default setting for enable_hashagg_disk |
| Previous Message | Stephen Frost | 2020-07-10 21:52:02 | Re: Default setting for enable_hashagg_disk |
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Alvaro Herrera | 2020-07-10 23:01:49 | Re: [HACKERS] PATCH: Batch/pipelining support for libpq |
| Previous Message | Daniel Gustafsson | 2020-07-10 21:55:59 | Re: Stale external URL in doc? |