DROP DOMAIN — remove a domain
DROP DOMAIN [IF EXISTS ] name [, ...] [ CASCADE | RESTRICT ]
IF EXISTSDo not throw an error if the domain does not exist. A notice is issued in this case.
nameThe name (optionally schema-qualified) of an existing domain.
CASCADEAutomatically drop objects that depend on the domain (such as table columns).
RESTRICTRefuse to drop the domain if any objects depend on it. This is the default.