Lehrgebiet Informationssysteme

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LG IS

AG DBIS

(C) AG DBIS

On the Modeling Power of Object-Relational Data Models in Technical Applications

Nan Zhang, Theo Härder

University of Kaiserslautern
P.O. Box 3049, 67653 Kaiserslautern, Germany
e-mail: haerder@informatik.uni-kl.de

Full paper (postscript version compressed by gzip)

Abstract:

Technical applications, that is, all kinds of engineering applications (CA*), are distinguished from usual business applications in that they require enhanced data modeling facilities and operations to cope with complex objects and their behavior. Emerging object-relational database management systems (ORDBMSs) which are conforming to the SQL3 standard promise to support technical applications more adequately as compared to conventional relational DBMS (RDBMSs). They offer concepts such as complex object support (that is, reference-based relationships), an extensible type system including set- valued attributes, DB-based abstract data types (ADTs), and more. However, modeling and processing support of complex objects and their versions, large objects, semantic-rich relationships, etc. is only rudimentary or even missing in current ORDBMSs.

Moreover, their architecture, functionality, and implementation are server-centric, that is, all DBMS functions are confined to the server. Technical applications, however, typically run in client/server environments where operation performance enabling interactive design work has to be provided. As a consequence, database management services have to be specialized for these performance requirements and, therefore, have to be dispersed across the server and the client side. Hence, used as database server technology, ORDBMSs have to be complemented by adequate client-side data management and long- running design transactions encapsulating the client processing model, in order to provide satisfactory support for technical applications.

This paper investigates the potential as well as the shortcomings of object-relational database technology for technical applications. Our observations are based on practical experiences with developing an integrated information system in a technical application domain. In this respect, we will evaluate the advantages and disadvantages of the enhanced ORDBMS facilities and identify areas which deserve refinements and improvements in future evolutions of both the standard and the systems.

Published in Proc. of the 1st East-European Symposium on Advances in Databases and Information Systems, St. Petersburg, 1997, pp. 318-325.