On using epsilon serializable locking protocol for concurrency control in real-time databases

New non-serializable protocols based on incorporating epsilon serializability (ESR) into the real-time concurrency control protocol, Hybrid Two Phase Locking (Hb2PL) are proposed. The protocols try to maximize the values of the transactions by making a compromise between meeting transaction deadlines and maintaining consistent transaction view. Two different ways of incorporating ESR into Hb2PL are suggested. One is called Partial ESR Hb2PL and the other is called Full ESR Hb2PL. Performance studies with simulation models indicate that their performance is much better than the SR based protocols, High Priority 2PL (H2PL) (R. Abbott and H. Garcia-Molina, 1992)