REAL-TIME TRANSACTION SCHEDULING: A COST-CONSCIOUS APPROACH By DONG-KWEON HONG A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE UNIVERSITY OF FLORIDA

of Thesis Presented to the Graduate School of the University of Florida in Partial Ful llment of the Requirements for the Degree of Master of Science REAL-TIME TRANSACTION SCHEDULING: A COST-CONSCIOUS APPROACH By DONG-KWEON HONG DECEMBER, 1992 Chairman: Dr. Sharma Chakravarthy Cochairman: Dr. Theodore Johnson Major Department: Computer and Information Sciences Real-time databases are an increasingly important component of embedded realtime systems. In a real-time database context, transactions must not only maintain the consistency constraints of the database but also satisfy the timing constraints speci ed for each transaction. Although several approaches have been proposed to integrate real-time scheduling and database concurrency control methods, none of them take into account the dynamic cost of scheduling a transaction as proposed in this thesis. In this thesis, we propose a new cost-conscious pre-analysis based realtime transaction scheduling algorithm which considers dynamic costs associated with a transaction. Our dynamic priority assignment algorithm adapts to changes in the system load without causing excessive numbers of transaction restarts. CHAPTER