Refinement preservation for rule selection in active object-oriented database systems

Rule selection in active object-oriented database systems is complicated because of the refinement preservation problem in traditional object-oriented paradigm. As a result, rules are not automatically inherited, and it is easy for the user to by-pass the rule checking mechanism and violate the semantic constraints defined by the application domain. We identify the above problem which is often neglected in existing active object-oriented database systems. We propose a dynamic inheritance mechanism and an operation/rule point of view notation in a generalized object-oriented model in which each object could have multiple representations in different classes. While the operation point of view enables the user to manipulate objects from different class point of view, the rule point of view ensures the correct selection of rules automatically. An overview of the rule execution model and system implementation is also given