Hi, On Thu, Jul 09, 2026 at 04:19:26AM +0000, Bertrand Drouvot wrote: > Hi, > > On Wed, Jul 08, 2026 at 02:08:00PM -0400, Andres Freund wrote: > > > Unfortunately I'm pretty doubtful that pgstat_backend.c is the right > > architectural direction. It'll just end up implementing all kinds of stats, > > since we'll incrementally want more and more per-backend stats. I think > > what > > we'd want is rather something where for each applicable stats kind we have a > > shared counter for all exited backends and then per-backend counters for > > live > > backends, with helpers to aggregate the exited + live stats to a total. > > That's a very nice proposal that would avoid the double counting. OTOH, that's > also a major re-design that would benefit all existing per-backend stats > kinds. > > I can see 2 options: > > 1/ > > step 1: Implement per-backend AIO stats (like proposed taking into account > your > remark about useless, derivable fields) + a global view. > step 2: work on the re-design > > 2/ > > step 1: work on the redesign > step 2: Add AIO stats based on the re-design > > The pros of 1/ is that step 1 would most probably land in 20, providing more > user > visibility (+ it could be used or improved during the AIO write project). > Step 2 > is a much larger project that might not land in 20. > > The cons, would be double counting (as there is no need to try to implement > something like [1] as we are going to re-design anyway). > > I'll be tempted to vote for 1/ to provide faster added value. What do you > (Andres, > Michael) think?
Actually, there is no rush to merge the per-backend AIO stats (we still have plenty of time for 20). So let's try option 2 and implement the new design first and see where it goes. I'll create a dedicated thread once ready. Regards, -- Bertrand Drouvot PostgreSQL Contributors Team RDS Open Source Databases Amazon Web Services: https://aws.amazon.com
