| From: | Peter Eisentraut <peter(dot)eisentraut(at)enterprisedb(dot)com> |
|---|---|
| To: | Richard Guo <guofenglinux(at)gmail(dot)com>, Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> |
| Cc: | PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>, David Rowley <dgrowleyml(at)gmail(dot)com>, Ranier Vilela <ranier(dot)vf(at)gmail(dot)com> |
| Subject: | Re: Improve list manipulation in several places |
| Date: | 2023-07-03 09:41:07 |
| Message-ID: | 81332e7b-6672-048b-3c0d-6a4c3735cdea@enterprisedb.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On 09.05.23 05:13, Richard Guo wrote:
>
> On Tue, May 9, 2023 at 1:26 AM Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org
> <mailto:alvherre(at)alvh(dot)no-ip(dot)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.
I have committed patch 0001. Since you have withdrawn 0002, this closes
the commit fest item.
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Peter Eisentraut | 2023-07-03 09:53:03 | Re: [PATCH] Remove unnecessary unbind in LDAP search+bind mode |
| Previous Message | Tomas Vondra | 2023-07-03 09:40:58 | Re: Should heapam_estimate_rel_size consider fillfactor? |