A STUDY OF INTEGRATED CONCURRENCY CONTROL PROTOCOLS FOR MRTDBS

Abstract

Although many efficient concurrency control protocols have been proposed in the literature for real-time database systems, they are mainly designed for the systems with a single type of real-time transactions. Not much work has been done in the joint scheduling of traditional non real-time transactions with combination of hard and soft real-time transactions. Du( to different performance requirement of each type of real-time transactions, these proposed protocols may not be suitable for Mixed Real-time Database Systems_ (M.R-TDBS) where soft, firm or hard real-time transactions, and even non real-time transactions, may co-exist in the systems at the same time. In this dissertation, we study the concurrency control problems for mixed real-time database systems, in which hard real-time, soft real-time and non real-time transactions exist simultaneously. We then study an Integrated Concurrency Control Protocol, which combines two phase locking and optimistic concurrency control protocols, for resolving inter-class conflicts among the real-time and non real-time transactions. We then evaluate the performance of the Integrated Concurrency Control Protocol under different real-time and non real-time supports, which aims to meet the deadline of soft real-time transactions and at the same time, minimize the response time of non real-time transactions.