Updates: The Neglected Operations

Mappings are the main instrument of describing relationships between data located in different independent data sources. The have been successfully used in P2P, information integration and data exchange systems. Unfortunately, most of the existing work has concentrated on data retrieval, partly ignoring changes that may happen to database schemas or their actual instances. In this talk, I claim that changes are of critical importance and the P2P and information integration communities cannot anymore have any more the luxury of ignoring them. I will show ways with which one can deal with changes at the schemas, at the instances and at the semantics of of the mappings.