| From: | John Naylor <john(dot)naylor(at)enterprisedb(dot)com> |
|---|---|
| To: | Robert Haas <robertmhaas(at)gmail(dot)com> |
| Cc: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Yura Sokolov <y(dot)sokolov(at)postgrespro(dot)ru>, Andres Freund <andres(at)anarazel(dot)de>, David Rowley <dgrowleyml(at)gmail(dot)com>, Tomas Vondra <tomas(dot)vondra(at)enterprisedb(dot)com>, Heikki Linnakangas <hlinnaka(at)iki(dot)fi>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: PG15 beta1 sort performance regression due to Generation context change |
| Date: | 2022-06-02 08:20:40 |
| Message-ID: | CAFBsxsG1Gv4q0vsfb9WTx2EfnhGiC=m32seLnWSMu7K+Jgz6fQ@mail.gmail.com |
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| Lists: | pgsql-hackers |
I ran a shorter version of David's script with just 6-9 attributes to
try to reproduce the problem area (spreadsheet with graph attached).
My test is also different in that I compare HEAD with just reverting
40af10b57. This shows a 60% increase in HEAD in runtime for 64MB
workmem and 64 byte tuples. It also shows a 20% regression for 32MB
workmem and 64 byte tuples.
I don't have anything to add to the discussion about whether something
needs to be done here for PG15. If anything, changing work_mem is an
easy to understand (although sometimes not practical) workaround.
--
John Naylor
EDB: http://www.enterprisedb.com
| Attachment | Content-Type | Size |
|---|---|---|
| Sort benchmark PG15 vs revert gen ctx JCN.ods | application/vnd.oasis.opendocument.spreadsheet | 34.9 KB |
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