On 2021-Mar-31, Tom Lane wrote:
> Yeah, that's been on the to-do list for a long time. The current
> theory about it is that NOT NULL constraints ought to be represented
> as entries in pg_constraint like CHECKs are, so that the inheritance
> count and so forth could be managed the same way. We could keep
> attnotnull for convenience but it'd just mirror the existence of
> the pg_constraint entry.
>
> IIRC Alvaro had a WIP patch for this, but I've not heard anything
> about it lately.
That one is the first thing on my list for the next cycle.
--
Álvaro Herrera Valdivia, Chile