An Approach for Deriving a Global Representation of Data Sources Having Different Formats and Structures

In this paper we propose an approach for deriving a global representation of data sources having different formats and structures. The proposed approach is based on the exploitation of a particular conceptual model for both uniformly representing such data sources and reconstructing both their intra-source and their inter-source semantics. Along with the global representation, our approach returns two support structures which improve the access transparency to stored information, namely, a set of mappings, encoding the transformations carried out during the construction of the global representation, and a set of views, allowing to obtain instances of the concepts of the global representation from instances of the concepts of the input data sources. The paper also describes a prototype which implements the proposed approach.A preliminary and partial version of this paper appears under the title A semi-automatic technique for constructing a global representation of information sources having different formats and structure in the Proceedings of the Conference Database and Expert System Applications (DEXA 2001), Munich, September 2001.