Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> writes:
> I started work on proposed check statement option and there are a few questions?
> what is sense of this statement for others PL?
IMO you should design this as a call to the PL's validator function.
It's not necessary to make other PLs do anything more than their
existing validators do (at least for now).
regards, tom lane