| From: | Andrei Lepikhov <a(dot)lepikhov(at)postgrespro(dot)ru> |
|---|---|
| To: | Richard Guo <guofenglinux(at)gmail(dot)com>, Nicolas Lutic <n(dot)lutic(at)loxodata(dot)com> |
| Cc: | pgsql-hackers(at)lists(dot)postgresql(dot)org |
| Subject: | Re: planner chooses incremental but not the best one |
| Date: | 2024-02-15 07:35:57 |
| Message-ID: | c6cf3fe8-8179-4b2e-9163-68941de0ed0a@postgrespro.ru |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On 15/12/2023 15:58, Richard Guo wrote:
> With the patch the estimate for the number of distinct 'b' values is
> more accurate.
+1 to commit this patch.
It looks good and resolves kind of a bug in the code.
>
> BTW, this patch does not change any existing regression test results. I
> attempted to devise a regression test that shows how this change can
> improve query plans, but failed. Should I try harder to find such a
> test case?
The test that was changed refers to different features. Its behaviour
can be changed in. the future, and mask testing of this code. IMO, you
should add a test directly checking appendrel->tuples correction.
--
regards,
Andrei Lepikhov
Postgres Professional
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Andy Fan | 2024-02-15 08:38:03 | Re: make add_paths_to_append_rel aware of startup cost |
| Previous Message | Amit Kapila | 2024-02-15 07:19:09 | Re: pg_upgrade and logical replication |