Hey hackers,
According to
http://www.postgresql.org/docs/9.2/static/extend-extensions.html
"PostgreSQL will not let you drop an individual object contained in an
extension, except by dropping the whole extension."
But this rule does not apply to domain constraints, i.e. it is not possible
to drop domain of some extenstion but it is possible to drop any or all of
its constraints. (And in fact drop it.)
I am consider this is a bug. Don't you?
--
// Dmitriy.