Semantic cooperation of legacy information systems: An object-oriented framework

When several legacy information systems have to cooperate, the issue is to define a global framework providing both semantic interoperability nad loose coupling among heterogeneous local information sources. To conciliate such requirements we propose an object oriented framework dedicated to global queries semantic evaluation and respecting local autonomy. Several layers insure interoperability through Application Objects and actual cooperation at a meta-level composed of Federative Objects. A unified description of local data allows structural and semantic evaluations during queries processing. To preserve the local autonomy, the description is dynamically derived from local data structures. Federative Objects exploit a cooperation protocol to coordinate the exchanges during queries evaluation.