On Mon, Jul 27, 2020 at 5:54 PM David Rowley <dgrowleyml@gmail.com> wrote:
> hmm. I'm not sure. I think this should follow the same logic as what
> "Disk Usage" follows, and right now we don't show Disk Usage unless we
> spill. Since we only use partitions when spilling, I don't think it
> makes sense to show the estimated partitions when we don't plan on
> spilling.
I'm confused about what the guiding principles for EXPLAIN ANALYZE
output (text or otherwise) are.
> I think if we change this then we should change Disk Usage too.
> However, I don't think we should as Sort will only show "Disk" if the
> sort spills. I think Hash Agg should follow that.
I don't follow your remarks here.
Separately, I wonder what your opinion is about what should happen for
the partial sort related EXPLAIN ANALYZE format open item, described
here:
https://www.postgresql.org/message-id/flat/20200619040358.GZ17995%40telsasoft.com#b20bd205851a0390220964f7c31b23d1
ISTM that EXPLAIN ANALYZE for incremental sort manages to show the
same information as the sort case, aggregated across each tuplesort in
a fairly sensible way.
(No activity over on the incremental sort thread, so I thought I'd ask
again here, while I was reminded of that issue.)
--
Peter Geoghegan