Learn More
Deductive object bases attempt to combine the advantages of deductive relational databases with those of object-oriented databases. We review modeling and implementation issues encountered during the development of ConceptBase, a prototype deductive object manager supporting the Telos object model. Significant features include: I) The symmetric treatment of(More)
ConceptBase is a deductive object-oriented database system intended for the management of metadata. A distinguishing feature of the Telos language underlying ConceptBase is the ability to manage rules and constraints across multiple levels of instantiation in so-called meta formulas, thus offering uniform consistency management across heterogeneous(More)
Most work on query optimization in relational and object-oriented databases has concentrated on tuning algebraic expressions and the physical access to the database contents. The attention to semantic query optimization, however, has been restricted due to its inherent complexity. We take a second look at the problem for queries in object-oriented databases(More)
Metadata has been identified as a key success factor in data warehouse projects. It captures all kinds of information necessary to analyse, design, build, use, and interpret the data warehouse contents. In order to spread the use of metadata, enable the interoperability between repositories, and tool integration within data warehousing architectures, a(More)
The ideal query language for a knowledge base will probably never be found: easy formulation and easy evaluation of queries are two connicting goals. Easy formulation asks for a exible, expressive language near to human language or gestures. The second goal requires an eeective mapping to machine code which computes the correct answer in a nite number of(More)