On Fri, Mar 6, 2020 at 6:59 PM Kirill Bychik <kirill.byc...@gmail.com> wrote: > > пт, 6 мар. 2020 г. в 20:14, Julien Rouhaud <rjuju...@gmail.com>: > > > > On Thu, Mar 5, 2020 at 8:55 PM Kirill Bychik <kirill.byc...@gmail.com> > > wrote: > > > I wanted to keep the patch small and simple, and fit to practical > > > needs. This patch is supposed to provide tuning assistance, catching > > > an io heavy query in commit-bound situation. > > > Total WAL usage per DB can be assessed rather easily using other means. > > > Let's get this change into the codebase and then work on connecting > > > WAL usage to (auto)vacuum stats. > > > > I agree that having a view of the full activity is a way bigger scope, > > so it could be done later (and at this point in pg14), but I'm still > > hoping that we can get insight of other backend WAL activity, such as > > autovacuum, in pg13. > > How do you think this information should be exposed? Via the > pg_stat_statement?
That's unlikely, since autovacuum won't trigger any hook. I was thinking on some new view for pgstats, similarly to the example I showed previously. The implementation is straightforward, although pg_stat_database is maybe not the best choice here. > Anyways, I believe this change could be bigger than FPI. I propose to > plan a separate patch for it, or even add it to the TODO after the > core patch of wal usage is merged. Just in case, if the problem is a lack of time, I'd be happy to help on that if needed. Otherwise, I'll definitely not try to block any progress for the feature as proposed. > Please expect a new patch version next week, with FPI counters added. Thanks!
