Re: cataloguing NOT NULL constraints

On 2022-Aug-22, Amit Langote wrote:

> Yeah, I think it makes sense to think of the NOT NULL constraints on
> their own in this case, without worrying about the PK constraint that
> created them in the first place.

Cool, that's enough votes that I'm comfortable implementing things that
way.

> BTW, maybe you are aware, but the legacy inheritance implementation is
> not very consistent about wanting to maintain the same NULLness for a
> given column in all members of the inheritance tree. For example, it
> allows one to alter the NULLness of an inherited column:

Right ... I think what gives this patch most of its complexity is the
number of odd, inconsistent cases that have to preserve historical
behavior. Luckily I think this particular behavior is easy to
implement.

> IIRC, I had tried to propose implementing the same behavior for legacy
> inheritance back in the day, but maybe we left it alone for not
> breaking compatibility.

Yeah, that wouldn't be surprising.

--
Álvaro Herrera PostgreSQL Developer — https://www.EnterpriseDB.com/
"The problem with the facetime model is not just that it's demoralizing, but
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