Skip to main content
SpringerLink
Log in

Algorithm to Process Read-only Transactions in Real-time Environments

  • Published:
Journal of Systems Integration

Abstract

In this study, we investigate a different approach to maintaining serializability in real-time database systems (RTDBS) such that concurrency among transactions can be increased. The study is motivated by the dominance of read only transactions (ROTs) in many real-time applications. Given the knowledge about the read/write characteristics of transactions, it can be more efficient and effective to process ROTs separately from update transactions (UTs). In particular, we have devised an independent algorithm to process ROTs while a conventional concurrency control protocol such as optimistic concurrency control (OCC) can be employed to process UTs. Using a separate algorithm to process ROTs can reduce the interference between UTs and ROTs. The undesirable overhead caused by transaction restart and blocking due to concurrency control can be alleviated. Consequently, the timeliness of the system can be improved. The performance of using this approach is examined through a series of simulation experiments. The results showed that the performance of ROTs in terms of miss rate and restart rate is improved significantly while the performance of UTs is also improved slightly. As a result, separate processing of ROTs is a viable approach that achieves better performance and resource utilization than using solely the OCC protocol, one of the best performing protocols in the literature of real-time database.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. H. Garcia-Molina and G. Wiederhold, “Read-only transactions in a distributed database,” ACM Transactions on Database Systems 7(2), pp. 209–234, 1982.

    Google Scholar 

  2. T. W. Kuo, Y. T. Kao, and L. Shu, “A two-version approach for real-time concurrency control and recovery,” Proceeding of the Third IEEE International High Assurance Systems Engineering Symposium, 1998.

  3. V. C. S. Lee, K. W. Lam, and S. H. Son, “Maintaining data consistency using timestamp ordering in real-time broadcast environments,” Proceedings of 6th International Conference on Real-time Computing Systems and Applications (RTCSA '99), pp. 29–36, 1999b.

  4. J. R. Haritsa, M. J. Carey, and M. Livny, “Data access scheduling in firm real-time database systems,” Real-time Systems 4(3), pp. 203–242, 1992.

    Google Scholar 

  5. J. Huang, J. A. Stankovic, K. Ramaritham, and D. Towley, “Experimental evaluation of real-time optimistic concurrency control schemes,” Proceedings of the 17th International Conference on Very Large Data Bases, pp. 35–46, 1991.

  6. K. Y. Lam, V. C. S. Lee, B. C. M. Kao, and S. L. Hung, “Priority assignment in distributed real-time databases using optimistic concurrency control,” IEE Proceedings Computers and Digital Techniques 144(5), pp. 324–330, 1997a.

    Google Scholar 

  7. K. W. Lam, S. H. Son and S. L. Hung, “A priority ceiling protocol with dynamic adjustment of serialization order,” Proceedings of the 13th International Conference on Data Engineering (ICDE'97), Birmingham, UK, April 7–11, 1997b.

  8. J. Lee and S. H. Son, “Using dynamic adjustment of serialization order for real-time database systems,” Proceedings of 14th IEEE Real-time Systems Symposium, 1993.

  9. V. C. S. Lee, K. Y. Lam, and B. Kao, “Priority scheduling of transactions in distributed real-time databases,” Real-time Systems 16(1), pp. 31–62, 1999a.

    Google Scholar 

  10. P. A. Bernstein, V. Hadzilacos, and N. Goodman, Concurrency Control and Recovery in Database Systems. Addison-Wesley: Reading, Mass, 1987.

    Google Scholar 

  11. J. Huang, J. A. Stankovic, K. Rammritham, D. Towsley, and B. Purimetla, “Priority inheritance in soft real-time databases,” Real-Time Systems 4(3), pp. 243–268, 1992.

    Google Scholar 

  12. L. Sha, R. Rajkumar, and J. Lehoczky, “Priority inheritance protocols: an approach to real-time synchronization,” IEEE Transactions on Computers 39(9), pp. 1175–1185, 1990.

    Google Scholar 

  13. T. W. Kuo and A. K. Mok, “Application semantics and concurrency control of real-time data intensive applications,” Proceedings of 13th IEEE Real-time Systems Symposium, 1992.

  14. T. W. Kuo and A. K. Mok, “SSP: a semantics-based protocol for real-time data access,” Proceedings of 14th IEEE Real-time Systems Symposium, 1993.

  15. S. H. Son and S. Kouloumbis, “A token-based synchronization scheme for distributed real-time databases,” Information Systems 18(6), 1993.

  16. K. L. Wu, P. S. Yu, and C. Pu, “Divergence control for epilson serializability,” Proceedings of the 8th International Conference on Data Engineering, 1992.

  17. N. C. Audsley, A. Burns, A., Richardson, M. F., and A. J. Wellings, “Data consistency in hard real-time systems,” Technical Report Department of Computer Science, University of York, 1993.

  18. K. J. Lin, S. Natarajan, and J. Liu, “Imprecise results: utilizing partial computations in real-time systems,” Proceedings of the 8th IEEE Real-Time Systems Symposium, 1987.

  19. K. Lin, “Consistency issues in real-time database systems,” Proceedings of the 22nd Hawaii International Conference on Systems Science, 1989.

  20. R. Abbott and H. Garcia-Molina, “Scheduling real-time transactions: a performance evaluation,” ACM Transactions on Database Systems 17, pp. 513–560, 1992.

    Google Scholar 

  21. J. R. Haritsa, M. J. Carey, and M. Livny, “Dynamic real-time optimistic concurrency control,” Proceedings of 11th Real-time Systems Symposium, pp. 94–103, 1990b.

  22. H. T. Kung and J. T. Robinson, “On optimistic methods for concurrency control,” ACM Transactions on Database Systems 6(2), pp. 213–226, 1981.

    Google Scholar 

  23. A. Datta, I. R. Viguier, S. H. Son, and V. Kumar, “A study of priority cognizance in conflict resolution for firm real time database systems,” in A. Bestavros and V. Fay-Wolfe (eds.), Real-Time Database and Information Systems: Research Advances, No. 10. Kluwer Academic Publishers, 1997.

  24. T. Haerder, “Observations on optimistic concurrency control schemes,” Information Systems 9(2), 1984.

  25. J. R. Haritsa, M. J. Carey, and M. Livny, “On being optimistic about real-time constraints,” Proceedings of the ACM SIGACT-SIGART-SIGMOD Symposium on Principles of Database Systems, 1990a.

  26. K. W. Lam, K. Y. Lam, and S. L. Hung, “Real-time optimistic concurrency control protocol with dynamic adjustment of serialization order,” Proceedings of IEEE Symposium on Real-time Technology and Applications, pp. 174–181, 1995.

  27. P. Konana, J. Lee, and S. Ram, “Updating timestamp interval for dynamic adjustment of serialization order in optimistic concurrency control-time interval (OCC-TI) protocol,” Information Processing Letters 63(4), pp. 189–193, 1997.

    Google Scholar 

  28. R. Abbott and H. Garcia-Molina, “Scheduling real-time transactions: a performance evaluation,” Proceedings of the 14th VLDB Conference, 1988.

  29. J. Lee and S. H. Son, “Concurrency control algorithms for real-time database systems,” in V. Kumar (ed.), Performance of Concurrency Control Mechanisms in Centralized Database Systems. Prentice Hall, 1996.

Download references

Author information

Authors and Affiliations

  1. Department of Computer Science, City University of Hong Kong, Hong Kong

    Victor C. S. Lee & Kwok-Wa Lam

Authors
  1. Victor C. S. Lee
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Kwok-Wa Lam
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Lee, V.C.S., Lam, KW. Algorithm to Process Read-only Transactions in Real-time Environments. Journal of Systems Integration 10, 355–373 (2001). https://doi.org/10.1023/A:1011253917819

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1023/A:1011253917819

Keywords

Search

Navigation