Re: Add RESPECT/IGNORE NULLS and FROM FIRST/LAST options - Mailing list pgsql-hackers

On Mon, Jan 20, 2025 at 12:31 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
> Tatsuo Ishii <ishii@postgresql.org> writes:
> >> I would think that
> >> IGNORE NULLS is potentially useful for user-defined window functions,
> >> and we should not be building anything that restricts the feature to
> >> specific functions.
>
> > So you want to allow to use IGNORE NULLS to other built-in window
> > functions?
>
> No, there needs to be a way for the individual window function to
> throw error if that's specified for a function that can't handle it.
> I'm just saying I don't want that to be hard-wired in some centralized
> spot.

Would it be acceptable to add a bool column to pg_proc, say
"pronulltreatment"? It would default to false, and an error would be
thrown if the null clause is specified for a function where it's set
to false?