Re: Removing unneeded self joins - Mailing list pgsql-hackers

On Mon, Jan 8, 2024 at 10:20 PM Alexander Korotkov <aekorotkov@gmail.com> wrote:
> On Mon, Jan 8, 2024 at 10:00 PM Alexander Lakhin <exclusion@gmail.com> wrote:
> > Please look at the following query which produces an incorrect result since
> > d3d55ce57:
> > CREATE TABLE t(a int PRIMARY KEY, b int);
> > INSERT INTO t VALUES  (1, 1), (2, 1);
> > SELECT * FROM t WHERE EXISTS (SELECT * FROM t t2 WHERE t2.a = t.b AND t2.b > 0);
> >
> >   a | b
> > ---+---
> >   1 | 1
> > (1 row)
> >
> > I think that the expected result is:
> >   a | b
> > ---+---
> >   1 | 1
> >   2 | 1
> > (2 rows)
>
> Thank you for your report.  I'm looking at this now.

Fixed in 30b4955a46.

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Regards,
Alexander Korotkov