Existing federated database systems (FDBS) provide uniform access to multiple heterogeneous DBS, but do not enable objects to move across the DBS while retaining global identity. To ful ll this requirement of industrial users, we provide a framework incorporating a exible object migration mechanism into FDBS. It o ers di erent capabilities for "what" and "how" to migrate: (1) di erent kinds of objects that exist within an FDBS, (2) various migration degrees that determine what data to migrate of an object, and (3) di erent operation primitives to move, replicate, and copy objects.
Elke Radeke, Marc H. Scholl