Re: BUG #17871: JIT during postgresql_fdw remote_estimates EXPLAIN have very negatively effect on planning time

On Tue, Mar 28, 2023 at 5:13 PM David Rowley <dgrowleyml@gmail.com> wrote:

> On Tue, 28 Mar 2023 at 17:54, Maxim Boguk <maxim.boguk@gmail.com> wrote:
> > During an attempt to create a minimal test case I discovered an effect
> for which I have no explanation:
> > (all tests with jit=on):
> >
> > Run EXPLAIN on the single partition, so far expected results...
> > explain select * from interview_review_info_archive_p028;
> >                                           QUERY PLAN
> >
> -----------------------------------------------------------------------------------------------
> >  Seq Scan on interview_review_info_archive_p028  (cost=0.00..361819.08
> rows=34546848 width=40)
> >  JIT:
> >    Functions: 2
> >    Options: Inlining true, Optimization true, Expressions true,
> Deforming true
>
> It could be something like a dropped column forcing projection of the
> SELECT *.  You might want to try without SELECT * using some subset of
> columns instead.
>
> Check if columns have been dropped with:
>
> select attnum,attname from pg_Attribute where
> attrelid='interview_review_info_archive_p028'::Regclass;
>
> David
>

Hi David,

You 100% right
negotiation_chat_archive=# explain select
topic_id,review_id,move_to_invitation_state_time,no_interview_reply_time,review_suggestion_chat_message_creation_time
from interview_review_info_archive_p028;
                                          QUERY PLAN

-----------------------------------------------------------------------------------------------
 Seq Scan on interview_review_info_archive_p028  (cost=0.00..361921.00
rows=34563080 width=40)

Exceptionally curious case when select * not equivalent select
list_all_columns from table...
Thank you.

-- 
Maxim Boguk
Senior Postgresql DBA
https://dataegret.com/

Phone UA: +380 99 143 0000
Phone AU: +61  45 218 5678