Re: BUG #17495: Regression in 15beta1 when filtering subquery including row_number window function

On Wed, 25 May 2022 at 12:51, Michael Paquier <michael@paquier.xyz> wrote:
>
> On Tue, May 24, 2022 at 04:17:35PM +0000, PG Bug reporting form wrote:
> > From testing with 15beta1, I think there is a regression in filtering a
> > subquery using the result of the row_number window function.  Here is the
> > code:
> >
> > This was discovered by the tests for Sequel, a Ruby database access
> > library.
>
> Inconsistency reproduced here, thanks for the detailed report and the
> test case!  I have added an open item:
> https://wiki.postgresql.org/wiki/PostgreSQL_15_Open_Items

Thanks for adding. I've put myself as the owner of this and will look
at it soon.

its baserestrictinfo, which is (x_sequel_row_number_x <= 2), when
generating SubqueryScan access paths for it.  As a result, the
WindowFunc target entry is removed as an unused targetlist item.

Thanks
Richard