Intensional and extensional integration and abstraction of heterogeneous databases

This paper presents two techniques to integrate and abstract database schemes. The techniques assume the existence of a collection of interscheme properties describing semantic relationships holding among input database scheme objects. The former technique uses interscheme properties to produce an integrated scheme encoding a global, unified view of the whole semantics represented within input schemes. The latter one takes a (integrated) scheme as the input and yields in output an abstracted scheme encoding the same semantics as the input scheme, but represented at an higher, application-dependent abstraction level. In addition, the paper illustrates a possible application of these algorithms to the construction of a data repository. Finally, the paper presents the application of proposed techniques to some database schemes of Italian Central Governmental Offices. (C) 2000 Elsevier Science B.V. All rights reserved.