Implementing Relationships and Constraints in an Object-Oriented Database Using a Monitor Construct

Semantic models have shown the utility of arbitrary user-defined relationships for defining the semantics of database information, while object-oriented models have developed a strong paradigm for the expression of individual database entities. The SORAC project merges the strengths of these two models by extending the object-oriented model through the addition of active semantic relationships. These active relationships express and enforce the constraints imposed on an object by the participation of the object in some group of related objects. The SORAC system is supported by the data definition language OIL (Object Interaction Language), which automatically maps schema specifications to a database implementation supported by the ONTOS Object Database Management System. By providing an automatic mapping from the semantic data model to the object-oriented database, the SORAC system provides a consistent semantic and structural view of the data.