Re: Improve list manipulation in several places
| От | Richard Guo |
|---|---|
| Тема | Re: Improve list manipulation in several places |
| Дата | |
| Msg-id | CAMbWs4-CzhHggsPeTToMQ4K5MMd4y7vcQsP5Cd2DTaoRuyGX+A@mail.gmail.com обсуждение исходный текст |
| Ответ на | Re: Improve list manipulation in several places (Alvaro Herrera <alvherre@alvh.no-ip.org>) |
| Ответы |
Re: Improve list manipulation in several places
|
| Список | pgsql-hackers |
On Tue, May 9, 2023 at 1:26 AM Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:
The problem I see is that each of these new functions has a single
caller, and the only one that looks like it could have a performance
advantage is list_copy_move_nth_to_head() (which is the weirdest of the
lot). I'm inclined not to have any of these single-use functions unless
a performance case can be made for them.
Yeah, maybe this is the reason I failed to devise a query that shows any
performance gain. I tried with a query which makes the 'all_pathkeys'
in sort_inner_and_outer being length of 500 and still cannot see any
notable performance improvements gained by list_copy_move_nth_to_head.
Maybe the cost of other parts of planning swamps the performance gain
here? Now I agree that maybe 0002 is not worthwhile to do.
Thanks
Richard
performance gain. I tried with a query which makes the 'all_pathkeys'
in sort_inner_and_outer being length of 500 and still cannot see any
notable performance improvements gained by list_copy_move_nth_to_head.
Maybe the cost of other parts of planning swamps the performance gain
here? Now I agree that maybe 0002 is not worthwhile to do.
Thanks
Richard
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