The Study Of An Enhanced Multi-Copy Distributed Concurrency Control

Concurrency Control mechanism is an important component of a database transaction management and one of important symbols of measuring functional strength and quality of database system. The purpose of distributed concurrency control is to ensure the consistency of distributed transaction and distributed database, realize the serializability of distributed transaction and make the transaction has a good concurrency to ensure the distributed system with a satisfied efficiency. The data in distributed system is distributed in the different sites linked by network. In order to improve the system availability, reliability and efficiency, distributed database always stored plenty of copies. Therefore, it increases the complexity of concurrency control.The article mainly studies the concurrency control mechanism of distributed transaction. The point is the multi-copy concurrency control. According to the distribution of data and multi-copy characteristics, it analyzes the method of traditional primary-copy blockage and put forward an enhanced primary-copy blockage concurrency control method and improves on the traditional method for the character of read and write. Experiment shows that compared with the traditional primary-copy blockage, the enhanced one can effectively reduce traffic and delays, increase the concurrency and avoid deadlock.