On Thu, Jul 22, 2021 at 8:45 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> That is ... weird. Maybe you have found a bug in the spill-to-disk logic;
> it's quite new after all. Can you extract a self-contained test case that
> behaves this way?
I wonder if this has something to do with the way that the input data
is clustered. I recall noticing that that could significantly alter
the behavior of HashAggs as of Postgres 13.
--
Peter Geoghegan