elein <elein(at)varlena(dot)com> writes:
> But I like the idea of centralizing the check in the input/output
> functions. It seems clearer and cleaner.
I remembered the problem with doing it that way: an input function can't
enforce a domain NOTNULL constraint, because it won't even get invoked
for a null input value. So there seems no way around having a special
case for domains in all places where I/O conversion is done.
regards, tom lane