On the Applicability of Schema Integration Techniques to Database Interoperation

. We discuss the applicability of schema integration techniques developed for tightly-coupled database interoperation to interoperation of databases stemming from different modelling contexts. We illustrate that in such an environment, it is typically quite difficult to infer the real-world semantics of remote classes from their definition in remote databases. However, defining relationships between the real-world semantics of schema elements is essential in existing schema integration techniques. We propose to base database interoperation in such environments on instance-level semantic relationships, to be defined using what we call object comparison rules. Both the local and the remote classifications of the appropriately merged instances are maintained, allowing for the derivation of a global class hierarchy if desired. 1 Introduction Interoperation among pre-existing, heterogeneous, and autonomous databases has been an important research topic in the last few years. Recently, the ..