Object-Oriented Data Integration

Large IS shops often work with three or more generations of database technology. It is very common to find some pilot projects, using object technology while the mass of software is still being produced using 3GL technologies and relational databases. Parallel to this application portfolio, older applications have to be maintained. These applications often use hierarchical or even older database technology. In most cases hierarchical databases still manage the main workload of commercial data processing. It is therefore important to be able to federate all the above generations of database technology. Object-oriented application development has to be able to reach data provided by other software generations. This may not result in changes to older applications. Objectoriented databases as a technology are not sufficient to provide this kind of parallel data integration. This article introduces an integration framework for several generations of database technology. The framework can be filled with multiple categories of database, middleware and other products. These are introduced and discussed in a separate section. As an example we will discuss a solution of the data integration problem for a large German financial institution, using an object-oriented access layer for heterogeneous databases. The focus here was on integration of all existing data sources. Object-oriented client/server applications have to coexist with classical host environments. This article features special conditions and requirements that can be found in a large IS shop. These requirements and the characteristic software environments that can be found there still rule out most commercially available integration products such as access layer products or object-oriented databases with relational gateways. About the authors Dipl.-Inform. Wolfgang Keller is a consultant with sd&m, software design & management GmbH & Co. KG in Munich/Germany. Dipl.-Inform. (BA) Christian Mitterbauer works for Bayerische Hypothekenund Wechselbank AG also in Munich/Germany. Dr. Klaus Wagner is also a consultant with sd&m. Authors can be reached via the Internet: [email protected], [email protected] and [email protected]. This work has been partially sponsored by the German Ministry of Research and Technology under contract 01 IS 508 A 0 . We would like to express our thanks. Special thanks to Dr. Thomas Becker for proof-reading. You must have had a horrible time Thomas. Object Oriented Data Integration Work in Progress, Printed 26.03.2001 Page i