Re: BUG #17233: Incorrect behavior of DELETE command with bad subquery in WHERE clause

On Sunday, October 17, 2021, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
>
> There might be an opportunity here to improve the error message's hint:
>
> regression=# SELECT CTID
> regression-# FROM tmp1
> regression-# INNER JOIN tmp2 ON tmp1.id = tmp2.id;
> ERROR: column "ctid" does not exist
> LINE 1: SELECT CTID
> ^
> HINT: There is a column named "ctid" in table "tmp1", but it cannot be
> referenced from this part of the query.
>
> "cannot be referenced" is probably a shade misleading, given the
> availability of the qualified-name alternative.
>
>
I was actually wondering why the error wasn’t an ambiguous column name
error. For a pure select query we already allow duplicate column names in
the result.

David J.