Abstract

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 incorporate into FDBS a exible object migration mechanism to move or duplicate objects from one component database system to another. We present di erent capabilities for "what " and "how " to migrate and consider the migration of both single objects and whole object graphs, i.e. an object together with related objects.