Re: BUG #14900: MView not null constraint

On 2017-11-12 12:12 PM, Tom Lane wrote:
> neil(at)postgrescompare(dot)com writes:
>> This is probably not a bug
>
> Nope, it isn't.
>
>> If it's not a bug should postgres support
>> ALTER MATERIALIZED VIEW ALTER COLUMN column SET NOT NULL syntax?
>
> Doesn't seem like a great idea to me. What's supposed to happen
> if a view update would result in a violation of the constraint?
> It's way too late to undo whatever change of the underlying data
> caused that, so it seems like the only possible answer is for
> REFRESHes to fail, resulting in the view getting more and more
> out of date until and unless something manual is done to resolve
> the problem. I can't see that that's a useful behavior to have.
>
> regards, tom lane
>
>

Makes sense. Seems like the scaffolding tool's problem and in fact they
do have a way to declare it non-nullable via comments now
https://github.com/gajus/postloader#handling-non-nullable-columns-in-materialized-views

Thanks for the info!

--
Neil Anderson
neil(at)postgrescompare(dot)com
http://www.postgrescompare.com