| From: | Peter Geoghegan <pg(at)bowt(dot)ie> |
|---|---|
| To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Cc: | Tomas Vondra <tomas(dot)vondra(at)enterprisedb(dot)com>, "kuroda(dot)hayato(at)fujitsu(dot)com" <kuroda(dot)hayato(at)fujitsu(dot)com>, PostgreSQL Hackers <pgsql-hackers(at)lists(dot)postgresql(dot)org> |
| Subject: | Re: Question: test "aggregates" failed in 32-bit machine |
| Date: | 2022-10-01 19:26:30 |
| Message-ID: | CAH2-Wzm8+4=zopa0Ee=TbeC12_b7xYH63sCc0O2EMZC=nPC98w@mail.gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On Sat, Oct 1, 2022 at 12:14 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> I spent some time today looking into the question of what our qsort
> code actually does. I wrote a quick-n-dirty little test module
> (attached) to measure the number of comparisons qsort really uses
> for assorted sample inputs.
Reminds me of the other sort testing program that you wrote when the
B&M code first went in:
https://www.postgresql.org/message-id/18732.1142967137@sss.pgh.pa.us
This was notable for recreating the tests from the original B&M paper.
The paper uses various types of test inputs with characteristics that
were challenging to the implementation and worth specifically getting
right. For example, "saw tooth" input.
--
Peter Geoghegan
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Andres Freund | 2022-10-01 19:44:15 | Re: [PATCH v1] [meson] add a default option prefix=/usr/local/pgsql |
| Previous Message | Tom Lane | 2022-10-01 19:13:59 | Re: Question: test "aggregates" failed in 32-bit machine |