Migrating Data-Oriented Applications to a Relational Database Management System

The need to update and reengineer legacy information systems to improve business processes and upgrade technology is becoming increasingly desirable for many organizations in the current economic climate. This involves migrating systems from centralized to distributed client-server architectures. These information systems are often written in COBOL, their data is stored on files and they use text-based user interfaces. In this paper, a method to migrate such an information system is presented. The target environment in our case is a relational database management system. In our method, the migration is carried out in an incremental way and by small steps. The migration process is driven by the data files. These files are previously arranged and then migrated in a defined order. An algorithm that defines the order of migration of the data files is described and an example is presented to clearly illustrate our method.