Re: pg_stat_reset_slru(name) doesn't seem to work as documented

On Fri, May 01, 2020 at 07:10:23PM +0900, Atsushi Torikoshi wrote:
>Hi,
>
>When I tried to reset a counter in pg_stat_slru using
>pg_stat_reset_slru(name),
>not only the specified counter but all the counters were reset.
>
> postgres=# SELECT * FROM pg_stat_slru ;
> name | blks_zeroed | blks_hit | blks_read | blks_written |
>blks_exists | flushes | truncates | stats_reset
>
>------------------+-------------+----------+-----------+--------------+-------------+---------+-----------+-------------------------------
> async | 3 | 0 | 0 | 3 |
> 0 | 0 | 0 | 2020-05-01 17:36:26.073433+09
> clog | 0 | 56 | 0 | 0 |
> 0 | 0 | 0 | 2020-05-01 17:36:26.073433+09
> commit_timestamp | 0 | 0 | 0 | 0 |
> 0 | 0 | 0 | 2020-05-01 17:36:26.073433+09
> (snip)
>
>
> postgres=# SELECT pg_stat_reset_slru('clog');
>
>
> postgres=# SELECT * FROM pg_stat_slru ;
> name | blks_zeroed | blks_hit | blks_read | blks_written |
>blks_exists | flushes | truncates | stats_reset
>
>------------------+-------------+----------+-----------+--------------+-------------+---------+-----------+-------------------------------
> async | 0 | 0 | 0 | 0 |
> 0 | 0 | 0 | 2000-01-01 09:00:00+09
> clog | 0 | 0 | 0 | 0 |
> 0 | 0 | 0 | 2020-05-01 17:37:02.525006+09
> commit_timestamp | 0 | 0 | 0 | 0 |
> 0 | 0 | 0 | 2000-01-01 09:00:00+09
> (snip)
>
>
>Attached a patch.
>

Yeah, that memset is a left-over from some earlier version of the patch.
Thanks for the report and patch, I'll push this shortly.

regards

--
Tomas Vondra http://www.2ndQuadrant.com
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