CDOL: a declarative platform for developing OODB applications

The authors present a rule-based database language known as CDOL (comprehensive declarative object language). CDOL provides sublanguages for the expression of derived data, constraints, updates, and integrity rules. The basic rule language provides an expressive approach to extending the stored database with virtual attributes and classes. The constraint sublanguage of CDOL allows explicit declarative specification of integrity constraints. The update sublanguage of CDOL enables ad-hoc declarative update requests, where the end-user is relieved from database consistency considerations. Integrity rules in CDOL are designed as active, user-transparent agents that supplement the declarative updates to complete update methods that preserve database consistency. An important contribution of CDOL is the active, integrity rule framework it establishes for integrating derived data, constraints and updates in a coherent and easy to use application-development platform for OODBs