Transaction Processing in Mobile Database Systems

In a mobile computing environment, a potentially large number of mobile and fixed users may simultaneously access shared data; therefore, there is a need to provide a means to allow concurrent management of transactions. Specific characteristics of mobile environments make traditional transaction management techniques no longer appropriate. This is due the fact that the ACID properties of transactions are not simply followed, in particular the consistency property. Thus, transaction management models adopting weaker form of consistency are needed and these models can now tolerate a limited amount of consistency. In this paper we have proposed (execution framework based on common ground shared by most of mobile transaction models found in the literature and investigate it under different execution strategies. More over, the effects of the fixed host transaction are identified and included in the evaluation The integration between wired and wireless environments confirms that the execution strategy is critical for the performance of a system. Neither MHS nor FHS are optimal in all situations and the performance penalties and wasted wireless resources can be substantial. A combined strategy CHS at least matches the best performance of the FHS and MHS and shows better performance than both in many cases.