ORDB via Prototype Delegation
An Extended ERD (EERD) can be implemented as either a relational RDB, object-oriented OODB, or object-relational ORDB. An OODB is supported by its own class-based data representations.
An ORDB can be class-based or prototype-based with delegation. (GEN is prototype-based.)
Prototype delegation does not rely on Class membership for method inheritance - it creates object-level relationships to support method delegation: ANY client object can ‘delegate’ any of its behavior to another server object via the oid equivalent of an fkey.
To make disciplined use of delegation requires some policy other than anarchy.