Horton

Thread

Commits

  1. Fix miscomputation of direct_lateral_relids for join relations.

  2. Undo mistaken tightening in join_is_legal().

  1. [sqlsmith] Planner error on lateral joins

    Andreas Seltenreich <seltenreich@gmx.de> — 2020-11-29T18:40:50Z

    Hi,

testing with sqlsmith on master at 3df51ca8b3 produced one instance of
the following error:

    ERROR:  failed to build any 6-way joins

I can reproduce it on a fresh regression database with the query below.
These were last logged in 2015.  Back then, it resulted in this commit:

    http://git.postgresql.org/pg/commitdiff/cfe30a72fa80528997357cb0780412736767e8c4

regards,
Andreas

select * from
  (select sample_1.a as c0
      from fkpart5.fk2 as sample_1) as subq_0,
  lateral (select  1
      from
 (select
  subq_0.c0 as c3,
  subq_5.c0 as c7,
  sample_2.b as c9
       from
  public.brin_test as sample_2,
  lateral (select
        subq_3.c1 as c0
      from
        fkpart5.pk3 as sample_3,
        lateral (select
       sample_2.a as c0,
       sample_3.a as c1
     from
       public.rtest_interface as ref_0
     ) as subq_1,
        lateral (select
       subq_1.c1 as c1
     from
       public.alter_table_under_transition_tables as ref_1
     ) as subq_3
      ) as subq_5) as subq_6
   right join public.gtest30_1 as sample_6
   on (true)
      where subq_6.c7 = subq_6.c3) as subq_7;

  2. Re: [sqlsmith] Planner error on lateral joins

    Tom Lane <tgl@sss.pgh.pa.us> — 2020-11-29T20:39:42Z

    Andreas Seltenreich <seltenreich@gmx.de> writes:
> testing with sqlsmith on master at 3df51ca8b3 produced one instance of
> the following error:
>     ERROR:  failed to build any 6-way joins

Thanks for the test case!  The attached modification to use only
longstanding test tables fails back to 9.5, but succeeds in 9.4.
I've not tried to bisect yet.

			regards, tom lane

  3. Re: [sqlsmith] Planner error on lateral joins

    Tom Lane <tgl@sss.pgh.pa.us> — 2020-11-30T02:18:15Z

    I wrote:
> Andreas Seltenreich <seltenreich@gmx.de> writes:
>> testing with sqlsmith on master at 3df51ca8b3 produced one instance of
>> the following error:
>> ERROR:  failed to build any 6-way joins

> Thanks for the test case!  The attached modification to use only
> longstanding test tables fails back to 9.5, but succeeds in 9.4.
> I've not tried to bisect yet.

Seems to be a missed consideration in add_placeholders_to_joinrel.
The attached fixes it for me.

			regards, tom lane