Re: per backend WAL statistics

Hi,

On Mon, Feb 17, 2025 at 04:25:46PM +0900, Michael Paquier wrote:
> On Mon, Feb 17, 2025 at 06:59:40AM +0000, Bertrand Drouvot wrote:
> > There is still something that would simplify what is done here: it's the
> > "the elimination of the write & sync columns for pg_stat_wal" mentioned in [2].
> 
> Yeah, still you cannot just remove them because the data tracked in
> pg_stat_io is not entirely the same, right?

I think that we can just remove them. They are tracked and incremented at the
exact same places in issue_xlog_fsync() and XLogWrite(). What differs is the
"bytes" (as pg_stat_wal.wal_bytes somehow "focus" on the wal records size while
the pg_stat_io's unit is the wal_block_size) and we keep them in both places.
Also it looks like we can get rid of PendingWalStats...

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