Treffer: Designing a User-Oriented Query Modification Facility in Object-Oriented Database Systems

The introduction of user-assisting features into database systems is discussed along two stages. The first stage involves a basic facility that can be used with standard database systems, whereas in the second stage such features are expanded in order to cope with object-oriented systems, adopting semantically richer data models. Examples involving categorization and role-specialization semantichierarchiesillustratethediscussion.Aclass/metaclassarchitecture,suchas that of the VODAK database system, an algebraic view of query processing and an extension of the object-oriented data model by rule systems are shown to be particularlysuitabletodesignandimplementuserassistanceonthedatabaseschema level. 1 Introduction As increasingly complex databases are designed, end users may find them too difficult to use. One runs the risk to produce systems that are rich in terms of the information they contain, but that no one is able to use appropriately. The problems of accessing data in a databa.