ADAPTIVE CONCURRENCY CONTROL SCHEMES SUPPORTING MOBILE CLIENT CACHING

In mobile client-server database systems, caching of frequently accessed data is an important technique that will reduce the contention on the narrow bandwidth wireless channel. As the server in mobile environments may not have any information about the state of its clients' cache (stateless server), using broadcasting approach to transmit the list of updated data to numerous concurrent mobile clients is an attractive approach. In this paper, two caching methods are proposed to support transaction semantics at mobile clients. Proposed protocols adopt asynchronous broadcasting and adaptive broadcasting as the way of sending invalidation reports, in order to dynamically adapt to system workload (update pattern, data locality). We study the performance of the proposed protocols by means of simulation experiments.