n Support for some object-oriented concepts The FDM is capable of supporting object
identity, inheritance through entity class hierarchies, function name overloading, and
navigational access.
n Support for referential integrity The FDM is an entity-based data model and implicitly
supports referential integrity.
n Irreducibility The FDM is composed of a small number of simple concepts that represent
semantically irreducible units of information. This allows a database schema to
be depicted graphically with relative ease thereby simplifying conceptual design.
n Easy extensibility Entity classes and functions can be added/deleted without requiring
modification to existing schema objects.
n Suitability for schema integration The conceptual simplicity of the FDM means that
it can be used to represent a number of different data models including relational,
network, hierarchical, and object-oriented. This makes the FDM a suitable model for
the integration of heterogeneous schemas within multidatabase systems (MDBSs) discussed
in Section 22.1.3.
n Declarative query language The query language is declarative with well-understood
semantics (based on lambda calculus). This makes the language easy to transform and
optimize.