A system for managing and querying a plurality of data sources, including an interface to a plurality of inter-related data sources of diverse types, each of the plurality of data sources having a schema that describes its data structure, a schema generator communicating with the interface, for generating a federated schema that describes the structures of the plurality of data sources and their inter-relationships, and for modifying the federated schema over time as the plurality of data sources undergo changes, and a query generator communicating with the schema generator, for generating a query for the federated schema. A method and a computer-readable storage medium are also described.