Concurrency Control in Real-Time Database System: Optimistic Scheme vs. Two-Phase Locking

The two-phase locking approach widely used for concurrency control in database systems have some inherent disadvantages such as deadlock and unpredictable blocking time. These appear to be serious problems with respect to real-time transaction processing, since in a real-time environ- ment transactions need to meet their time constraints as well as their consistency requirements. Integrated with CPU scheduling, we investigate an optimistic concurrency control approach for real- time transaction processing, which possesses the properties of deadlock freedom and predictable blocking time. We also give solutions to the problem of transaction starvation. The proposed optimistic concurrency control scheme is implemented on a real-time database testbed. The per- formance results show that the optimistic scheme outperforms two-phase locking even when the system is CPU bound.

[1]  Lui Sha,et al.  Concurrency control for distributed real-time databases , 1988, SGMD.

[2]  Umeshwar Dayal,et al.  Time-critical database scheduling: a framework for integrating real-time scheduling and concurrency control , 1989, [1989] Proceedings. Fifth International Conference on Data Engineering.

[3]  Jiandong Huang.  Real-time transaction processing: design, implementation, and performance evaluation , 1991 .

[4]  J. Stankovic,et al.  Buuer Management in Real-time Databases , 1990 .

[5]  John A. Stankovic,et al.  Buffer Management in Real-Time Databases , 1990 .

[6]  Gunter Schlageter,et al.  Redesign of optimistic methods: Improving performance and applicability , 1986, 1986 IEEE Second International Conference on Data Engineering.

[7]  Miron Livny,et al.  Concurrency control performance modeling: alternatives and implications , 1987, TODS.

[8]  Hector Garcia-Molina,et al.  Scheduling real-time transactions , 1988, SGMD.

[9]  John A. Stankovic,et al.  On real-time transactions , 1988, SGMD.

[10]  Irving L. Traiger,et al.  The notions of consistency and predicate locks in a database system , 1976, CACM.

[11]  J. T. Robinson,et al.  On optimistic methods for concurrency control , 1979, TODS.

[12]  Donald F. Towsley,et al.  Experimental evaluation of real-time transaction processing , 1989, [1989] Proceedings. Real-Time Systems Symposium.

[13]  Hector Garcia-Molina,et al.  Scheduling real-time transactions: a performance evaluation , 1988, TODS.

[14]  Michael Stonebraker,et al.  The Performance of Concurrency Control Algorithms for Database Management Systems , 1984, VLDB.

[15]  K.-J. Lin,et al.  Consistency issues in real-time database systems , 1989, [1989] Proceedings of the Twenty-Second Annual Hawaii International Conference on System Sciences. Volume II: Software Track.

[16]  David J. DeWitt,et al.  Integrated concurrency control and recovery mechanisms: design and performance evaluation , 1985, TODS.

[17]  Daniel A. Menascé,et al.  Optimistic versus pessimistic concurrency control mechanisms in database management systems , 1982, Inf. Syst..

[18]  Sang Hyuk Son,et al.  Using Replication for High Performance Database Support in Distributed Real-Time Systems , 1987, RTSS.