On incremental cache coherency schemes in mobile computing environments

Re-examines the cache coherency problem in a mobile computing environment in the context of relational operations (i.e. selection, projection and join). We propose a taxonomy of cache coherency schemes, and as case studies, we pick several schemes for further study. These schemes are novel in several ways. First, they are incremental. Second, they are an integration of (and built on) techniques in view maintenance in centralized systems and cache invalidation in client-server computing environments. We conducted extensive studies based on a simulation model. Our study shows the effectiveness of these algorithms in reducing uplink transmission and average access times. Moreover, the class of algorithms that exploit collaboration between the client and server performs best in most cases. We also study extended versions of this class of algorithms to further cut down on the work performed by the server.