Re: BUG #19435: Error: "No relation entry for relid 2" Triggered by Complex Join with Self-Referencing Tables

On Tue, Mar 17, 2026 at 2:14 PM Fujii Masao <masao.fujii@gmail.com> wrote:
>
> On Tue, Mar 17, 2026 at 7:34 PM PG Bug reporting form
> <noreply@postgresql.org> wrote:
> >
> > The following bug has been logged on the website:
> >
> > Bug reference:      19435
> > Logged by:          Hang ammmkilo
> > Email address:      ammmkilo@163.com
> > PostgreSQL version: 18.3
> > Operating system:   Ubuntu 22.04
> > Description:
> >
> > A user encountered an error when attempting to execute a query involving
> > multiple RIGHT JOIN operations and a NATURAL JOIN on the same table
> > (pg_table_a). The error message returned was:
> > [XX000]ERROR: no relation entry for relid 2
> > This error seems to be an internal one and should not be triggered by users.
> > It might be a bug.
> > ```sql
> > DROP TABLE IF EXISTS pg_table_a;
> >
> > CREATE TABLE pg_table_a (
> >     id INTEGER PRIMARY KEY,
> >     col_bool BOOLEAN
> > );
> >
> > INSERT INTO pg_table_a (id, col_bool)
> > VALUES (5, TRUE);
> >
> > SELECT  1 AS c1
> > FROM (
> >     pg_table_a AS tom0
> >     RIGHT JOIN (
> >         (pg_table_a AS tom1 NATURAL JOIN pg_table_a AS tom2)
> >         RIGHT JOIN pg_table_a AS tom3
> >         ON tom1.col_bool IS NOT NULL
> >     )
> >     ON tom1.col_bool
> > );
> > ```
>
> Thanks for the report!
>
> I was able to reproduce this issue on the master. git bisect that I ran pointed
> to commit fc069a3a631 as the likely cause. So I've CC'd its committer,
> Alexander, on this thread.

Thank you for adding me to the thread.  I'm lookin at this.

------
Regards,
Alexander Korotkov
Supabase