Re: compute_query_id and pg_stat_statements

On Thu, May 13, 2021 at 09:41:42PM -0400, Bruce Momjian wrote:
> On Fri, May 14, 2021 at 09:40:15AM +0800, Julien Rouhaud wrote:
> > On Fri, May 14, 2021 at 8:13 AM Bruce Momjian <bruce@momjian.us> wrote:
> > >
> > > On Thu, May 13, 2021 at 08:04:37PM -0400, Álvaro Herrera wrote:
> > > > Here's a first attempt at what was suggested.  If you say "auto" it
> > > > remains auto in SHOW, but it gets enabled if a module asks for it.
> > > >
> > > > Not final yet, but I thought I'd throw it out for early commentary ...
> > >
> > > I certainly like this idea better than having the extension change the
> > > output of the GUC.
> > 
> > Oh, I didn't understand that it was the major blocker.  I'm fine with it too.
> 
> I think if we keep the output as 'auto', and document that you check
> pg_stat_activity for a hash to see if it is enabled, that gets us pretty
> far.

I think keeping the output as 'auto', and documenting that this query
must be run to determine if the query id is being computed:

    SELECT query_id
    FROM pg_stat_activity
    WHERE pid = pg_backend_pid();

is the right approach.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

  If only the physical world exists, free will is an illusion.