Note: The following description applies both to Postgres-XC and PostgreSQL if not described explicitly.
DROP DOMAIN removes a domain. Only the owner of a domain can remove it.
Do not throw an error if the domain does not exist. A notice is issued in this case.
The name (optionally schema-qualified) of an existing domain.
Automatically drop objects that depend on the domain (such as table columns).
Refuse to drop the domain if any objects depend on it. This is the default.