17. The system of claim 15 wherein said view generator updates the database view when a relevant business rule is changed.
15. The system of claim 14 further comprising a view generator communicating with the schema-to-ontology generator, wherein the view generator generates a database view of the plurality of inter-related data sources, using the federated schema, wherein the database view is formulated in terms an expression language that uses the classes, the properties, the inheritances, and the business rules, and wherein said query generator generates a query for the database view.