Transaction management in a mobile data access system

Advances in wireless networking technology and portable computing devices have led to the emergence of the mobile computing paradigm. As a result, the traditional notion of timely and reliable access to global information sources in a distributed system or multidatabase system is rapidly changing. Users have become much more demanding in that they desire and sometimes even require access to information anytime, anywhere. The amount and the diversity of information that is accessible to a user are also growing at an exponential rate. Compounding the access to information is the wide variety of technologies with differing memory, network, power, and display requirements. Within the scope of distributed databases and multidatabases, the issue of concurrency control as a means to provide timely and reliable access to the information sources has been studied in detail. In an MDAS environment, concurrent execution of transaction is more problematic due to the power and resource limitations of computing devices and lower communication rate of the wireless communication medium. This article is intended to address the issue of concurrency control within a multidatabase and an MDAS environment. Similarities and differences of multidatabases and MDAS environment are discussed. Transaction processing and concurrency control issues are analyzed. Finally, a taxonomy for concurrency control algorithms for both multidatabases and MDAS environments is introduced