Real-Time Concurrency Control Protocol Based on Accessing Temporal Data

Concurrency control is one of the main issues in the studies of real-time database systems. On the one hand, it is related closely to active real-time database and real-time application. Concurrency control algorithm seriously affect the performance of the system in real-time, may cause unpredictable consequences. On the other hand, updating data in active real-time database may trigger a new transaction and to further increase the difficulty of the concurrency control. How ensures both the consistency of the database and the finish of the transactions before deadline; it is an important problem to the concurrency control research in the active real-time database systems. In the most literature, the existing research more focuses on the transactions deadline and lack of attention the data temporal constraint. This is mainly due to the real-time data is obtained dynamically by sensors in real-time database, and the transactions of real-time databases read the sensor data only, do not write the sensor data. But the real-time data may miss deadline and become invalid before transaction which reads it committed, most concurrency control algorithms are regardless of the sensor data deadline and its invalid effect to systems. This chapter will further discuss the concurrency control method that transactions access real-time sensor data.