On Mon, Jul 27, 2020 at 12:52 PM Alvaro Herrera
<alvherre@2ndquadrant.com> wrote:
> On 2020-Jul-27, Peter Geoghegan wrote:
> > The v4-0001-Remove-hashagg_avoid_disk_plan-GUC.patch changes are
> > surprisingly complicated. It would be nice if you could take a look at
> > that aspect (or confirm that it's included in your review).
>
> I think you mean "it replaces surprisingly complicated code with
> straightforward code". Right? Because in the previous code, there was
> a lot of effort going into deciding whether the path needed to be
> generated; the new code just generates the path always.
Yes, that's what I meant.
It's a bit tricky. For example, I have removed a redundant
"cheapest_total_path != NULL" test in create_partial_grouping_paths()
(two, actually). But these two tests were always redundant. I have to
wonder if I missed the point. Though it seems likely that that was
just an accident. Accretions of code over time made the code work like
that; nothing more.
--
Peter Geoghegan