Abstract
A crucial consideration in environments where data is broadcast to clients is the low bandwidth available for clients to communicate with servers. Advanced applications in such environments do need to read data that is mutually consistent as well as current. However, given the asymmetric communication capabilities and the needs of clients in mobile environments, traditional serializability-based approaches are too restrictive, unnecessary, and impractical. We thus propose the use of a weaker correctness criterion called update consistency and outline mechanisms based on this criterion that ensure (1) the mutual consistency of data maintained by the server and read by clients, and (2) the currency of data read by clients. Using these mechanisms, clients can obtain data that is current and mutually consistent “off the air”, i.e., without contacting the server to, say, obtain locks. Experimental results show a substantial reduction in response times as compared to existing (serializability-based) approaches. A further attractive feature of the approach is that if caching is possible at a client, weaker forms of currency can be obtained while still satisfying the mutual consistency of data.
- Ach95 S. Acharya, et. al. Broadcast Disks: Data Management for Asymmetric Communications Environments. Proceedings of the A CM SIGMOD Conference, California, May 1995. Google ScholarDigital Library
- Ach96 S. Achaxya, M. Franklin and S. Zdonik. Disseminating Updates on Broadcast Disks Proceedings of the VLDB Conference, Mumbai(Bombay), India, 1996. Google ScholarDigital Library
- Alo90 R. Alonso, D. Barbara and H. Garcia-Molina. Data Caching issues in an Information Retrieval System. A CM 7t~ansactions on Database Systems, 15(3), September 1!990. Google ScholarDigital Library
- Ber87 P. Bernstein, V. Hadzilacos and N. Goodman. Concurrency Control and Recovery in Database Systems. Addison-Wesley, Massachusetts, 1987. Google ScholarDigital Library
- Bob92 P.M. Bober and M.J. Carey. Multiversion Query Locking. Proceedings of the VLDB Conference, Vancouver, Canada, August 1992. Google ScholarDigital Library
- Bob93 P.M. Bober and M.J. Carey. Multiversion Query Locking. Computer Science Technical Report TR 1160, University of Wisconsin-Madison, 1993.Google Scholar
- Car91 M.J. Carey, et. al. Data Caching Tradeoffs in Client-Server DBMS Architectures. Proceedings of the A CM SIGMOD Conference, Denver, June 1991. Google ScholarDigital Library
- Fra93 M.J. Franklin. Caching and Memory Management in Client-Server Database Systems. Ph.D. Thesis, University of Wisconsin-Madison, 1993. Google ScholarDigital Library
- Guk96 S. Gukal, E. Omiecinski and U. Ramachandran. Transient Versioning for Consistency and Concurrency in Client-Server Systems. Proceex!ings of the Conference on Parallel and Distributed l~formation Systems (PDIS), Florida, December 19~'6. Google ScholarDigital Library
- Her87 G. Herman, et. al. The Datacycle Archltecture for Very High Throughput Database Systenas Proceedings of the A CM SIGMOD Conference, 1987. Google ScholarDigital Library
- Imi94 T. Imielinski and B.R. Badrinath. Mobile Wireless Computing: Challenges in Data M~magement. Communications of the ACM, 37(10), 1994. Google ScholarDigital Library
- Kum97 S. Kumar, E. Kwang and D. Agrawal. Caprera: An Activity Framework for Transaction Processing on Wide-Area Networks Proceedings o} the ViSDB Conference, Athens, Greece, August 19.c17. Google ScholarDigital Library
- Mol82 H. Garcia-Molina and G. Wiederhohi. Read- Only Transactions in a Distributed Database. A CM 7~nsactions on Database Systems, 7(2), 1982. Google ScholarDigital Library
- Oki93 B. Oki, et. al. The Information Bus- An Architecture for Extensible Distributed Systems. Proceedings of the SOSP Conference, Nort}l Carolina, December 1993. Google ScholarDigital Library
- Pap88 C.H. Papadimitriou. The Theory of Database Concurrency Control. Computer Science Prq~ss, 1988. Google ScholarDigital Library
- Pit99 E. Pitoura and P. Chrysanthis, Scalable Processing of Read-Only Transactions in Broadcast Push, IEEE International Conference on Distributed Computing Systems, Austin, 1999 Google ScholarDigital Library
- Ram96 K. Ramamritham and P. Chrysanthis. A Ta~onomy of Correctness Criteria in Databa~e Applications. VLDB Journal, 5(1), January 1996. Google ScholarDigital Library
- Sha99 J. Shanmugasundaram, et. al. Efficiellt Concurrency Control for Broadcast Environmqmts Univ. of Massachusetts Technical Report 199g.Google Scholar
- She94 S. Shekar and D. Liu. Genesis and Advanced Traveler Information Systems (ATIS): Killer App}tications for Mobile Computing. MOBID.~.TA Workshop, New Jersey, 1994.Google Scholar
- Vit White Paper, http://www.vitria.com.Google Scholar
- Wan91 W. Wang and L. Rowe. Cache Consi,~tency and Concurrency Control in a Client/Ser~,er DBMS Architecture. Proceedings of the A CM" SIGMOD Conference, June 1991. Google ScholarDigital Library
- Wei87 W. Weihl. Distributed Version Manal,~ement for Read-Only Actions. IEEE Transactior~s on Software Engineering, 13(1), January 1987. Google ScholarDigital Library
- Wil90 W. Wilkinson and M.A. Nemat. Iv{aintaining Consistency of Client Cached Data. JYroceedings of the VLDB Conference, Australia, Au,,ust 1990. Google ScholarDigital Library
- Xua97 P. Xuan, et. al. Broadcast on Demand- Efficient and Timely Dissemination of Data in Mobile Environments. IF, BE Real-Time Tech~wlogy and Applications Symposium, June 1997, pp 38-48. Google ScholarDigital Library
Index Terms
- Efficient concurrency control for broadcast environments
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