Re: per backend WAL statistics

Hi,

On Mon, Mar 03, 2025 at 09:17:30AM +0000, Bertrand Drouvot wrote:
> hmm, that would work as long as PGSTAT_BACKEND_FLUSH_ALL represents things
> that need to be called from pgstat_report_wal(). But I think that's open
> door for issue should be add a new PGSTAT_BACKEND_FLUSH_XXX where XXX is not
> related to pgstat_report_wal() at all. So, I'm tempted to keep it as it is.

I just realized that pgstat_flush_backend() is not correct in 0001. Indeed
we check:

"
if (pg_memory_is_all_zeros(&PendingBackendStats,
sizeof(struct PgStat_BackendPending)))
return false;
"

but the WAL stats are not part of PgStat_BackendPending... So we only check
for IO pending stats here. I'm not sure WAL stats could be non empty if IO
stats are but the attached now also takes care of pending WAL stats here.

Regards,

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