Re: exposing wait events for non-backends (was: Tracking wait event for latches)

On Tue, Oct 4, 2016 at 11:59 AM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> On Mon, Oct 3, 2016 at 8:43 PM, Michael Paquier
> <michael(dot)paquier(at)gmail(dot)com> wrote:
>> The rest looks good to me. Thanks for the feedback and the time!
>
> Thanks for the fixes. I committed this with an additional compile
> fix, but the buildfarm turned up a few more problems that my 'make
> check-world' didn't find. Hopefully those are fixed now, but we'll
> see.

So, one of the problems in this patch as committed is that for any
process that doesn't show up in pg_stat_activity, there's no way to
see the wait event information. That sucks. I think there are
basically two ways to fix this:

1. Show all processes that have a PGPROC in pg_stat_activity,
including auxiliary processes and whatnot, and use some new field in
pg_stat_activity to indicate the process type.

2. Add a second view, say pg_stat_system_activity, to show the
processes that don't appear in pg_stat_activity. A bunch of columns
could likely be omitted, but there would be some duplication, too.

Preferences?

--
Robert Haas
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