Re: Report planning memory in EXPLAIN ANALYZE

On Thu, Jan 18, 2024 at 4:42 PM Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> wrote:
>
> On 2024-Jan-18, Ashutosh Bapat wrote:
>
> Hmm ... TBH I don't like the "showed_planning" thing very much, but if
> we need to conditionalize the printing of "Planning:" on whether we
> print either of buffers or memory, maybe there's no way around something
> like what you propose.

right.

>
> However, I don't understand this output change, and I think it indicates
> a bug in the logic there:
>
> > diff --git a/src/test/regress/expected/explain.out b/src/test/regress/expected/explain.out
> > index 86bfdfd29e..55694505a7 100644
> > --- a/src/test/regress/expected/explain.out
> > +++ b/src/test/regress/expected/explain.out
> > @@ -331,15 +331,15 @@ select explain_filter('explain (memory) select * from int8_tbl i8');
> > explain_filter
> > ---------------------------------------------------------
> > Seq Scan on int8_tbl i8 (cost=N.N..N.N rows=N width=N)
> > - Planner Memory: used=N bytes allocated=N bytes
> > + Memory: used=N bytes, allocated=N bytes
> > (2 rows)
>
> Does this really make sense?

The EXPLAIN output produces something like below
explain_filter
---------------------------------------------------------
Seq Scan on int8_tbl i8 (cost=N.N..N.N rows=N width=N)
Planning:
Memory: used=N bytes, allocated=N bytes
(3 rows)

but function explain_filter(), defined in explain.sql, removes line
containing Planning: and we end up with output
explain_filter
---------------------------------------------------------
Seq Scan on int8_tbl i8 (cost=N.N..N.N rows=N width=N)
Memory: used=N bytes, allocated=N bytes
(2 rows)

Hence this weird difference.

--
Best Wishes,
Ashutosh Bapat