In this presentation, we will describe a collection of new object-relational features that have been added to IBM's DB2 Universal Database (UDB) system. The features to be described include support for structured types, object references, and hierarchies of typed tables and views. These features will be covered from the perspective of a database designer or end user. In addition to presenting the features presently available in DB2 UDB V5.2, which became available in Fall 1998, we will discuss the expected evolution and impact of this technology over time.

Object-relational database systems, a.k.a. “universal servers,” are emerging as the next major generation of commercial database system technology. Products from relational DBMS vendors including IBM, Informix, Oracle, UniSQL, and others, include object-relational features today, and all of the major vendors appear to be on course to delivering full object-relational support in their products over the next few years. In addition, the SQL3 standard is rapidly solidifying in this area. The goal of this tutorial is to explain what the key features are of object-relational database systems, review what today's products provide, and then look ahead to where these systems are heading. The presentation will be aimed at general SIGMOD audience, and should therefore be appropriate for users, practitioners, and/or researchers who want to learn about object-relational database systems.

No abstract available.

Advanced data models and knowledge models together with their powerful query and manipulation languages have already proven to be essential for systems that support non-standard applications such as engineering and knowledge-based application systems. In order to raise their usability and acceptability, it is overly important to provide adequate implementation techniques that guarantee extensible and efficient processing for this advanced DBMS scenario. In this paper we present design alternatives and implementation techniques for such kinds of advanced DBMS, strongly focussing on query and knowledge processing in client/server architectures. To discuss our considerations and implementation technologies, we refer to the knowledge-processing framework of the KBMS KRISYS, although our ideas are generally applicable to (advanced) DBMS.

A great variety of techniques has been developed to optimize and enhance query processing for relational, client/server, distribute~ parallel, and heterogeneous database systems (DBS).Baaed on that work and experience, we investigate how far those techniques are applicable to query processing in Knowledge Base Management Systems (KBMS).Our reference system is the KRISYS KBMS that consists of a knowledge-processing system at the client (clientbaaed processing) and a data-processing system at the server (database backend).We describe a unifying thrnework for query ,processing incorporating both processing systems (as realized in KRISYS).This allows to distribute and balance the amount of work done in the client and in the server.Based on an evaluation of that framework, severaf approaches to further enhance knowledge processing are reported.