A New Method for Unifying Heterogeneous Databases

In this article we present a new method for unifying heterogeneous databases. We propose the unification at the level of conceptual schemas in a two-step process. First, the internal database schemas are mapped to conceptual schemas in a user interactive process. These schemas are then automatically integrated, creating a virtual repository. Virtual repositories give users the feeling of working with single, local databases and can be used for epidemiological research (e.g. data analysis) or clinical practice. We implemented the proposed method in a tool for accessing medical information from remote databases located at different machines with different technological platforms in the Internet.