Re: pg_stat_statements requires compute_query_id

po 10. 5. 2021 v 19:03 odesílatel Maciek Sakrejda <m(dot)sakrejda(at)gmail(dot)com>
napsal:

> On Mon, May 10, 2021 at 7:43 AM Julien Rouhaud <rjuju123(at)gmail(dot)com> wrote:
> > On Mon, May 10, 2021 at 04:36:16PM +0200, Pavel Stehule wrote:
> > > I expected just an empty column query_id and workable extension. This
> > > doesn't look well.
> > >
> > > More, it increases the (little bit) complexity of migration to
> Postgres 14.
> >
> > This was already raised multiple times, and the latest discussion can be
> found
> > at [1].
> >
> > Multiple options have been suggested, but AFAICT there isn't a clear
> consensus
> > on what we should do exactly, so I've not been able to send a fix yet.
> >
> > [1]:
> https://www.postgresql.org/message-id/flat/35457b09-36f8-add3-1d07-6034fa585ca8%40oss.nttdata.com
>
> Before it petered out, the thread seemed to be converging toward
> consensus that the situation could be improved. I work on pganalyze,
> and our product requires pg_stat_statements to be enabled for a lot of
> its functionality. We guide our users through enabling it, but if
> additional steps are required in 14, that may be confusing. I don't
> have any strong feelings on the particular mechanism that would work
> best here, but it would be nice if enabling pg_stat_statements in 14
> did not require more work than in 13. Even if it's just one extra
> setting, it's another potential thing to get wrong and have to
> troubleshoot, plus it means all existing pg_stat_statements guides out
> there would become out of date.
>

+1

minimally it requires extra notes in some migration guide.

I understand so queryid is one from key values. So it is not possible to
merge data with and without a queryid. My idea about the best solution is
something like pg_stat_statements can work without a queryid, and when the
compute_query_id is changed, then the values stored in pg_stat_statements
are resetted. I have no idea if it can be implemented. Current state is not
user friendly. The people who know the previous behaviour can be very
confused.

Regards

Pavel

> Thanks,
> Maciek
>