Re: Question: test "aggregates" failed in 32-bit machine
Peter Geoghegan <pg@bowt.ie>
From: Peter Geoghegan <pg@bowt.ie>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Tomas Vondra <tomas.vondra@enterprisedb.com>, "kuroda.hayato@fujitsu.com" <kuroda.hayato@fujitsu.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2022-10-01T19:26:30Z
Lists: pgsql-hackers
On Sat, Oct 1, 2022 at 12:14 PM Tom Lane <tgl@sss.pgh.pa.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
Commits
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Revert "Optimize order of GROUP BY keys".
- f4c7c410ee4a 16.0 landed
- 443df6e2db93 15.0 landed