Abstract
The use of mobile computers is gaining popularity. The number of users with laptops and notebooks is increasing and this trend is likely to continue in the future where the number of mobile clients will far exceed the number of traditional xed clients. Applications running on mobile clients download information by periodically connecting to repositories of data. Mobile clients constitute a new and different kind of workload and exhibit different access patterns than those seen in traditional client server systems. Though le systems have been modified to handle clients that are capable of downloading information, updating the information while disconnected, and later reintegrating the updates, databases have not been redesigned to accommodate mobile clients. Thus, there is a need to support mobile clients in the context of client server databases. In this paper, we present a new architecture for database systems which takes mobile environments into consideration. This architecture allows us to address issues of concurrency control, disconnection, replica control in mobile databases. We also propose the concept of hoard keys which facilitates hoarding. We present simulation results that illustrate the performance of an example database system with both disconnected and traditional clients.