Optimistic single-phase validation scheme for transaction management in mobile database systems

Abstract

In a mobile computing environment in which communication channels are limited and have low-bandwidths, mobile transactions are long-lived and frequently disconnected with their wireless network in processing. Such peculiarities of mobile transactions make existing transaction scheduling schemes inadequate and raise new challenging research problems. We proposed a new scheduling scheme called Optimistic Single-Phase Validation for transaction scheduling in mobile database management, OSV for short. Compared to other concurrency control schemes of Distributed Database Systems in which the validation of global transaction is achieved in two-phase, OSV decreases the number of messages through wireless communication channels which can be easily delayed and disconnected. OSV has shown to prevent indefinite postponement and cascading delay associated with Optimistic Concurrencty Control scheme and Optimistic Two-Phase Locking Scheme in Mobile Distributed Database Systems. Based on the results of the performance evaluation, we conclude that OSV outperforms the other schemes such as O2PL and OCC for the disconnection toleraable requierment. OSV also has the higher probability of the transaction restart compared to other schemes.