From: | Alexander Lakhin <exclusion(at)gmail(dot)com> |
---|---|
To: | "Hayato Kuroda (Fujitsu)" <kuroda(dot)hayato(at)fujitsu(dot)com>, 'Amit Kapila' <amit(dot)kapila16(at)gmail(dot)com> |
Cc: | 'Michael Paquier' <michael(at)paquier(dot)xyz>, 'Robert Haas' <robertmhaas(at)gmail(dot)com>, 'Jeff Davis' <pgsql(at)j-davis(dot)com>, 'Heikki Linnakangas' <hlinnaka(at)iki(dot)fi>, "'pgsql-hackers(at)postgresql(dot)org'" <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: Is this a problem in GenericXLogFinish()? |
Date: | 2023-11-30 11:00:01 |
Message-ID: | 9aa385d8-fe75-c35b-cf91-31bb3647d977@gmail.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
Hello Kuroda-san,
30.11.2023 10:28, Hayato Kuroda (Fujitsu) wrote:
> Again, good catch. Here is my analysis and fix patch.
> I think it is sufficient to add an initialization for writebuf.
I agree with the change. It aligns hash_xlog_squeeze_page() with
hash_xlog_move_page_contents() in regard to initialization of writebuf.
Interestingly enough, the discrepancy exists since these functions
appeared with c11453ce0, and I can't see what justified adding the
initialization inside hash_xlog_move_page_contents() only.
So I think that if this doesn't affect performance, having aligned coding
(writebuf initialized in both functions) is better.
> I want to add a test case for it as well. I've tested on my env and found that proposed
> tuples seems sufficient.
> (We must fill the primary bucket, so initial 500 is needed. Also, we must add
> many dead pages to lead squeeze operation. Final page seems OK to smaller value.)
>
> I compared the execution time before/after patching, and they are not so different
> (1077 ms -> 1125 ms).
>
> How do you think?
I can confirm that the test case proposed demonstrates what is expected
and the duration increase is tolerable, as to me.
Best regards,
Alexander
From | Date | Subject | |
---|---|---|---|
Next Message | Gabriele Bartolini | 2023-11-30 11:01:54 | Re: Extend pgbench partitioning to pgbench_history |
Previous Message | Alena Rybakina | 2023-11-30 10:57:26 | Re: POC, WIP: OR-clause support for indexes |