An optimal construction of invalidation reports for mobile databases

Mobile computing is characterized by frequent disconnection, limited communication capability, narrow bandwidth, etc. Caching can play a vital role in mobile computing by reducing the amount of data transferred. In order to reuse caches after short disconnections, invalidation reports are broadcasted to clients to help update/invalidate their caches. Detailed reports may not be desirable because they can be very long and consume large bandwidth. On the other hand, false invalidations may set in if detailed timing information of updates is not provided in the report. In this research, we aim to reduce the false invalidation rates of the reports. It is found that false invalidation rates are closely related to clients' reconnection patterns (i.e., the distribution of the time spans between disconnections and reconnections). By using Newton's method, we show how a report with a minimal false invalidation rate can be constructed for any given disconnection pattern.

[1]  Kevin Wilkinson,et al.  Maintaining Consistency of Client-Cached Data , 1990, VLDB.

[2]  Michael Stonebraker,et al.  "The Committee for Advanced DBMS Function": Third Generation Data Base System Manifesto , 1990, SIGMOD Conference.

[3]  Miron Livny,et al.  Global Memory Management in Client-Server Database Architectures , 1992, VLDB.

[4]  Lawrence A. Rowe,et al.  Cache consistency and concurrency control in a client/server DBMS architecture , 1991, SIGMOD '91.

[5]  David R. Cheriton,et al.  Leases: an efficient fault-tolerant mechanism for distributed file cache consistency , 1989, SOSP '89.

[6]  Michael J. Franklin.  Global Memory Management , 1996 .

[7]  Miron Livny,et al.  Data caching tradeoffs in client-server DBMS architectures , 1991, SIGMOD '91.

[8]  Ahmed K. Elmagarmid,et al.  Wireless client/server computing for personal information services and applications , 1995, SGMD.

[9]  Tomasz Imielinski,et al.  Sleepers and workaholics: caching strategies in mobile environments , 1994, SIGMOD '94.

[10]  Michael Stonebraker,et al.  Third-generation database system manifesto , 1990, SGMD.

[11]  Beng Chin Ooi,et al.  On incremental cache coherency schemes in mobile computing environments , 1997, Proceedings 13th International Conference on Data Engineering.

[12]  Philip S. Yu,et al.  Energy-efficient caching for wireless mobile computing , 1996, Proceedings of the Twelfth International Conference on Data Engineering.

[13]  M. Franklin,et al.  Global Memory Management in Client-Server DBMS Architectures , 1992 .

[14]  Heinz Schmidt,et al.  Proceedings of the 2nd Australian Workshop on Mobile Computing and Databases and Applications , 1997 .

[15]  Daniel Barbará,et al.  Mobile Computing and Databases - A Survey , 1999, IEEE Trans. Knowl. Data Eng..

[16]  Tomasz Imielinski,et al.  Energy efficient indexing on air , 1994, SIGMOD '94.

[17]  Ahmed K. Elmagarmid,et al.  Bit-Sequences: An adaptive cache invalidation method in mobile client/server environments , 1997, Mob. Networks Appl..

[18]  Haengrae Cho,et al.  Data Caching with Incremental Update Propagation in Mobile Computing Environments , 1998, Aust. Comput. J..