Re: Add proper planner support for ORDER BY / DISTINCT aggregates
| От | Richard Guo |
|---|---|
| Тема | Re: Add proper planner support for ORDER BY / DISTINCT aggregates |
| Дата | |
| Msg-id | CAMbWs4_+5cP+8xjiAc=hds935ZiiG6oepPDeVNovWhQ66DARJw@mail.gmail.com обсуждение исходный текст |
| Ответ на | Re: Add proper planner support for ORDER BY / DISTINCT aggregates (David Rowley <dgrowleyml@gmail.com>) |
| Ответы |
Re: Add proper planner support for ORDER BY / DISTINCT aggregates
|
| Список | pgsql-hackers |
On Tue, Nov 8, 2022 at 9:31 AM David Rowley <dgrowleyml@gmail.com> wrote:
I've been playing around with the attached patch which does:
1. Adjusts add_paths_to_grouping_rel so that we don't add a Sort path
when we can add an Incremental Sort path instead. This removes quite a
few redundant lines of code.
For unsorted paths, the original logic here is to explicitly add a Sort
path only for the cheapest-total path. This patch changes that and may
add a Sort path for other paths besides the cheapest-total path. I
think this may introduce in some unnecessary path candidates.
I think it's good that this patch removes redundant codes. ISTM we can
do the same when we try to finalize the partially aggregated paths from
partially_grouped_rel.
Thanks
Richard
path only for the cheapest-total path. This patch changes that and may
add a Sort path for other paths besides the cheapest-total path. I
think this may introduce in some unnecessary path candidates.
I think it's good that this patch removes redundant codes. ISTM we can
do the same when we try to finalize the partially aggregated paths from
partially_grouped_rel.
Thanks
Richard
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