Re: WAL usage calculation patch

> > There is a higher-level Instrumentation API that can be used with
> > INSTRUMENT_WAL flag to collect the wal usage information. I believe
> > the instrumentation is widely used in the executor code, so it should
> > not be a problem to colelct instrumentation information on autovacuum
> > worker level.
> >
> > Just a recommendation/chat, though. I am happy with the way the data
> > is collected now. If you commit this variant, please add a TODO to
> > rework wal usage to common instr API.
>
>
> The instrumentation is somewhat intended to be used with executor nodes, not
> backend commands. I don't see real technical reason that would prevent that,
> but I prefer to keep things as-is for now, as it sound less controversial.
> This is for the 3rd patch, which may not even be considered for this CF anyway.
>
>
> > > > As for the tests, please get somebody else to review this. I strongly
> > > > believe checking full page writes here could be a source of
> > > > instability.
> > >
> > >
> > > I'm also a little bit dubious about it. The initial checkpoint should make
> > > things stable (of course unless full_page_writes is disabled), and Cfbot also
> > > seems happy about it. At least keeping it for the temporary tables test
> > > shouldn't be a problem.
> >
> > Temp tables should show zero FPI WAL records, true :)
> >
> > I have no objections to the patch.
>
>
> I'm attaching a v5 with fp records only for temp tables, so there's no risk of
> instability. As I previously said I'm fine with your two patches, so unless
> you have objections on the fpi test for temp tables or the documentation
> changes, I believe those should be ready for committer.

No objections on my side either. Thank you for your review, time and efforts!