On Mon, Jul 20, 2020 at 09:17:21AM -0400, Tom Lane wrote:
>Tomas Vondra <tomas.vondra@2ndquadrant.com> writes:
>> There's a minor problem here, though - these stats were collected before
>> we fixed the tlist issue, so hashagg was spilling about 10x the amount
>> of data compared to sort+groupagg. So maybe that's the first thing we
>> should do, before contemplating changes to the costing - collecting
>> fresh data. I can do that, if needed.
>
>+1. I'm not sure if we still need to do anything, but we definitely
>can't tell on the basis of data that doesn't reliably reflect what
>the code does now.
>
OK, will do. The hardware is busy doing something else at the moment,
but I'll do the tests and report results in a couple days.
regards
--
Tomas Vondra http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services