Bidirectional Mappings for Data and Update Exchange

Abstract

A key challenge in supporting information interchange is not only supporting queries over integrated data, but also updates. Previous work on update exchange has enabled update propagation over schema mappings in a unidirec-tional way-conceptually similar to view maintenance, in that a derived instance gets updated based on changes to a source instance. In this paper, we consider how to support data and update propagation across bidirectional map-pings that enable different sites to mirror each other's data. We show how data and update exchange can be extended to support bidirectional updates, implement an algorithm to perform side-effect-free update propagation in this model, and show preliminary results suggesting our approach is feasible .