| From: | David Rowley <dgrowleyml(at)gmail(dot)com> |
|---|---|
| To: | Nathan Bossart <nathandbossart(at)gmail(dot)com> |
| Cc: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, andrewbille(at)gmail(dot)com, pgsql-bugs(at)lists(dot)postgresql(dot)org |
| Subject: | Re: BUG #19086: pg_dump --data-only selects and do not uses index definitions for the dumped tables. |
| Date: | 2025-10-15 21:38:09 |
| Message-ID: | CAApHDvrcM4G0==52jFoAvmxk6ZRjXKq7nkik=fqq6BH=dSJsYA@mail.gmail.com |
| Views: | Whole Thread | Raw Message | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-bugs |
On Thu, 16 Oct 2025 at 05:24, Nathan Bossart <nathandbossart(at)gmail(dot)com> wrote:
> I tried this with ignore_system_indexes = on, too, but it was very slow.
Seems to be due to pg_get_indexdef / pg_get_constraintdef operating on
a cold cat cache. Getting rid of those the rewritten version runs in
1.8 seconds with 100k tables for me.
That invalidates my timings from yesterday as I must have run the
rewritten query once the catcache was populated. Here are updated
results.
ignore_system_indexes = on 1.5k tables:
master: Execution Time: 26167.741 ms
rewritten: Execution Time: 16661.774 ms
ignore_system_indexes = off 1.5k tables:
master: Execution Time: 105.415 ms
rewritten: Execution Time: 97.030 ms
So not as good.
David
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Tom Lane | 2025-10-15 21:55:28 | Re: BUG #19086: pg_dump --data-only selects and do not uses index definitions for the dumped tables. |
| Previous Message | Masahiko Sawada | 2025-10-15 18:35:07 | Re: TRAP: failed Assert("outerPlan != NULL") in postgres_fdw.c |