Propagation of semantic modifications to an integrated schema

Abstract

We present a methodology to semi-automatically propagate semantic modifications on local schemas of a federated database to the integrated schema. Our approach is based on a declarative schema integration methodology, called SIM, which accomplishes schema integration by resolving a set of equivalence correspondences between arbitrarily complex local subschemas. This paper extends this methodology with a more diversified set of semantic correspondences and with an approach to integrate schemas incrementally. On this basis, local schema changes can be modelled as semantic correspondences between subschemas, which extend or alter the correspondences that have led to the existing integrated schema. Propagating these changes to the integrated schema then amounts in incrementally revising the affected original schema correspondences and reintegrating the affected portions of the integrated schema.