Re: log_autovacuum in Postgres 14 -- ordering issue

On Wed, Aug 25, 2021 at 2:07 PM Stephen Frost <sfrost(at)snowman(dot)net> wrote:
> I generally like the idea though I'm not sure about changing things in
> v13 as there's likely code out there that's already parsing that data
> and it might suddenly break if this was changed.

Agreed -- I won't backpatch anything to v13.

> Given that such code would need to be adjusted for v14 anyway, I don't
> really see changing it in v14 as as being an issue (nor do I feel that
> it's even a big concern at this point in the release cycle, though
> perhaps others feel differently).

BTW, I noticed one thing about the track_io_time stuff. Sometimes it
looks like this:

I/O timings:

i.e., it doesn't show anything at all after the colon. This happens
because the instrumentation indicates that no time was spent on either
read I/O or write I/O.

I now wonder if we should just unconditionally report both things
(both "read:" and "write:"), without regard for whether or not they're
non-zero. (We'd do the same thing with ANALYZE's equivalent code too,
if we actually did this -- same issue there.)

--
Peter Geoghegan