Re: Flush pgstats file during checkpoints

Hi,

On Mon, Aug 26, 2024 at 01:56:40PM +0900, Michael Paquier wrote:
> On Fri, Aug 02, 2024 at 02:11:34AM +0900, Michael Paquier wrote:
> > Applied 0003 for now to add the redo LSN to the pgstats file, adding
> > the redo LSN to the two DEBUG2 entries when reading and writing while
> > on it, that I forgot. (It was not 01:57 where I am now.)
> >
> > Attached is the last one.
>
> The CF bot has been complaining in injection_points as an effect of
> the stats remaining after a crash, so rebased to adapt to that.

Thanks!

Checking the V7 diffs as compared to V4:

1. In pgstat_write_statsfile():

- elog(DEBUG2, "writing stats file \"%s\"", statfile);
+ elog(DEBUG2, "writing stats file \"%s\" with redo %X/%X", statfile,
+ LSN_FORMAT_ARGS(redo));

2. and the ones in injection_points/t/001_stats.pl:

+# On crash the stats are still there.
$node->stop('immediate');
$node->start;
$numcalls = $node->safe_psql('postgres',
"SELECT injection_points_stats_numcalls('stats-notice');");
-is($numcalls, '', 'number of stats after crash');
+is($numcalls, '3', 'number of stats after crash');
$fixedstats = $node->safe_psql('postgres',
"SELECT * FROM injection_points_stats_fixed();");
-is($fixedstats, '0|0|0|0|0', 'fixed stats after crash');
+is($fixedstats, '1|0|2|1|1', 'fixed stats after crash');

They both LGTM.

Regards,

--
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com