A methodology for interschema relationship identification in heterogeneous databases

information shoring among databases, scientific or business, requires the development of techniques for accessing data porn multiple heterogeneous databases. Orie approach to providing interoperability among these databases, is to de$ne one or more federated schemas which represent a coherent view of the underlying databases. A review of existing research on schema integration, the process of generating integrated schemas, points to the need for development of techniques for identifying objects in multiple databases that may be related This process of interschema relationship identification is the focus of this paper. In this paper, we present a methodology for utilizing schematic as well as integrity constraint knowledge for interschsma relationship identification. We present the details of a comprehensive set of heuristics for schematic interschema relationship identification. We also introduce the concept of constraint-based relationships and describe how such relationships can be generated. Finally, we describe heuristics for generating “real world” interschema relationships based on the schematic and constraint-based relationships generated.