Research On Quality Of Service Of Temporal Consistency In Real-time Database System

With Real-time Database System integrates real-time technology and database technology deeply, its complexities are reflected in many terms such as theory, function, application and characteristic etc. It can not only support the demands of managing data objects in real-time environment, but also provide the service of updating data objects timely. In recent years, as Internet technology develops, real-time database technology has been applied in applications of service class such as video transmission and multi-management etc.It is an ideal scenario that guaranteeing all of the temporal consistency of the real-time data objects in the research of Real-time Database System. Hard Real-time Database System must satisfy with the ideal scenario strictly, but it may become more difficult to maintain the performance when the number of transactions released at the same time increased. However, Soft Real-time Database System need not satisfy the ideal scenario. Generally, in order to maintain quality of service of temporal consistency(Qo S) at some level user-required, the scheduling system will give up some jobs which may influence the proper execution of other jobs. So, Soft Real-time Database System can adapt the working state well. Therefore, the topic about optimizing Qo S has certain theoretical and practical significance in Soft Real-time Database System research.The characteristics of Real-time Database System are discussed in terms of management module and operation in this thesis. Then the problem of Qo S is studied in Soft Real-time Database System. Secondly, four traditional algorithms about temporal consistency of data objects are studied systematically in Hard Real-time Database System and both SML and DS-PS algorithms are researched especially in Soft Real-time Database System. At last, an optimization method named SDS-OPT which combined deferrable scheduling of DS-PS algorithm with increasing filtered base-values mind of SML-OPT algorithm has been proposed. Meanwhile, the schedulable condition of DS-PS algorithm is researched and improved. The algorithm analysis and experimental results show that the new algorithm SDS-OPT can promote Qo S effectively.