A Replication Schema to Support Weak Connectivity in Mobile Information Systems

. We present a replication schema, appropriate for distributed environments where connectivity is weak, partial or variant such as in mobile information systems. The schema is based on augmenting the database interface with operations with weaker consistency guarantees. An implementation of the schema based on distinguishing copies into quasi and core is presented and protocols for enforcing it are introduced. Then, practical examples of its applicability are described. The performance of the weak consistency schema is evaluated for various networking conditions by using an analytical model developed for this purpose. 1 Introduction Advances in telecommunications and in the development of portable computers have provided for wireless communications that permit users to actively participate in distributed computing even while moving. The resulting distributed environment is subject to restrictions imposed by the nature of the wireless medium [5, 6, 11]. Mobile computing is susceptible ..