Concurrency Control in Real-Time Databases by Dynamic Adjustment of Serialization Order

Time-critical scheduling in real-time database systems has two components: real-time transaction scheduling, which is related to task scheduling in realtime operating systems, and concurrency control, which can be considered as operation level scheduling. Most current research in this area only focuses on the transaction scheduling aspact while the concurrency control part remains untouched. In the paper, a new concurrency control algorithm for real-time database systems is proposed, by which real-time scheduling and concurrency control can be integrated. The algorithm is based on a priority-based locking mechanism to support time-critical scheduling by adjusting the serialization order dynamically in favor of high priority transactions. Furthermore, it does not assume any knowledge about the data requirements or execution time of each transaction. This makes the algorithm very practical.