AN EXECUTABLE META MODEL FOR RE-ENGINEERING OF DATABASE SCHEMAS

A logical database schema, e.g. a relational one, is the implementation of a specification, e.g. an entity-relationship diagram. Upcoming new data models require a cost-effective method for mapping from one data model to the other. We present an approach where the mapping process is divided into three parts. The first part reformulates the source and target data models into a so-called meta model. The second part classifies the input schema into the meta model, yielding a data model-independent representation. The third part synthesizes the output schema in terms of the target data model. The meta model, the data models as well as the schemas are all represented in the logic-based formalism of O-Telos. Its ability to quantify across data model concepts is the key to classifying schema elements independently of their data model. A prototype has been implemented on top of the deductive object base manager ConceptBase for the mapping of relational schemas to entity-relationship diagrams. From this, a C++-based tool has been derived as part of a commercial CASE environment for database applications.