Re: BUG #18261: Inconsistent results of SELECT affected by joined subqueries

On Mon, Jan 8, 2024 at 3:10 PM Alexander Korotkov <aekorotkov(at)gmail(dot)com> wrote:
> On Mon, Jan 8, 2024 at 2:49 PM Alexander Korotkov <aekorotkov(at)gmail(dot)com> wrote:
> > On Mon, Jan 8, 2024, 13:51 Richard Guo <guofenglinux(at)gmail(dot)com> wrote:
> >> On Fri, Jan 5, 2024 at 11:32 AM Andrei Lepikhov <a(dot)lepikhov(at)postgrespro(dot)ru> wrote:
> >>>
> >>> The regression test shows where two fully equal join clauses, applied on
> >>> different join levels, differ by the only required_relids. It covers the
> >>> problem and can be helpful by itself. IMO, one line in this test is
> >>> redundant (see attachment).
> >>
> >>
> >> Hmm, I don't think the insert statement in the test case is redundant.
> >> It's needed to verify that the query in the test case gives the correct
> >> result. Without the insert statement, the wrong plan would give the
> >> same result as the correct plan, i.e., an empty set in this case.
> >>
> >> IMO, if we make some code changes and add a test case for that, we need
> >> to ensure the test can give a different (and correct of course) result
> >> than what came before.
> >
> > Thank you for pointing this. Yes, veryfying query result not just plan is strengthening the test. I'll recheck this and push the fix later today.
>
> Pushed. Thanks again, Richard.

I also noticed my indent oversight. Will fix that later today.

https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=koel&dt=2024-01-08%2014%3A19%3A03

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Regards,
Alexander Korotkov