Re: Skip temporary table schema name from explain-verbose output.

On Tue, Apr 27, 2021 at 7:08 PM Bharath Rupireddy
<bharath(dot)rupireddyforpostgres(at)gmail(dot)com> wrote:
>
> On Tue, Apr 27, 2021 at 6:59 PM Ashutosh Bapat
> <ashutosh(dot)bapat(dot)oss(at)gmail(dot)com> wrote:
> >
> > On Tue, Apr 27, 2021 at 12:23 PM Amul Sul <sulamul(at)gmail(dot)com> wrote:
> > > >
> > > > How about using an explain filter to replace the unstable text
> > > > pg_temp_3 to pg_temp_N instead of changing it in the core? Following
> > > > are the existing explain filters: explain_filter,
> > > > explain_parallel_append, explain_analyze_without_memory,
> > > > explain_resultcache, explain_parallel_sort_stats, explain_sq_limit.
> > > >
> > >
> > > Well, yes eventually, that will be the kludge. I was wondering if that
> > > table is accessible in a query via pg_temp schema then why should
> > > bother about printing the pg_temp_N schema name which is an internal
> > > purpose.
> >
> > Although only the associated session can access objects from that
> > schema, I think, the entries in pg_class have different namespace oids
> > and are accessible from other sessions. So knowing the actual schema
> > name is useful for debugging purposes. Using auto_explain, the explain
> > output goes to server log, where access to two temporary tables with
> > the same name from different sessions can be identified by the actual
> > schema name easily.
> >

Make sense, we would lose the ability to differentiate temporary
tables from the auto_explain logs.

Regards,
Amul