Re: [PATCH] Don't block HOT update by BRIN index

On Tue, Nov 30, 2021 at 08:11:03PM +0100, Tomas Vondra wrote:
> OK,
>
> I've polished the last version of the patch a bit (added a regression test
> with update of attribute in index predicate and docs about the new flag into
> indexam.sgml) and pushed.

brin.sql's new brin_hot test is failing sometimes.

I saw a local failure and then found this.
https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=serinus&dt=2021-12-01%2003%3A00%3A07

SELECT pg_stat_get_tuples_hot_updated('brin_hot'::regclass::oid);
pg_stat_get_tuples_hot_updated
--------------------------------
- 1
+ 0
(1 row)

Evidently because:
| 2021-12-01 04:02:01.096 CET [61a6e587.3106b1:4] LOG: wait_for_hot_stats delayed 33.217301 seconds

It seems like maybe the UDP packet lost to the stats collector got lost ?
It fails less than 10% of the time here, probably depending on load.

BTW there's a typo in brin.sql: precicates

--
Justin