Research And Application Of Embedded Mobile Database Synchronization Model Based On Time And Cache Weighting

Mobile database technology is a branch of distributed database and distributed computing. The creation and development of mobile database in order to meet the requirements of data access in mobile computing environment, mobile database is extension and expansion of Traditional Distributed Database. At present, mobile database is a new research directions about Distributed Database, it involved Database Technology,Distributed Computing Technology,Mobile communication technology and many other fields.Maintain data consistency is the important issues of mobile database Research. Great differences between mobile computing environment and traditional distributed environment, make data processing technology of Traditional Distributed Database difficult to effectively apply of mobile database, this requires how to resolve the question of data consistency about mobile database, according to characteristics of mobile computing environment itself.The so-called data consistency is Data consistency between data of mobile terminals cache and data of servers, when the update the data of servers can reflect to the mobile terminals timely, mobile terminals update the data can reflect to the servers also, and Sent to the corresponding mobile terminals.The article to solve the problem of data consistency based on the mobile database replication and caching technology research. On the basis of analysis the inadequate about problem of data consistency, with characteristics of mobile computing environment cache weakly consistency, proposed a synchronization model about mobile database of based on time and cache weighting, to solve consistency question between server database and mobile database.Firstly, mobile terminal update local database in the circumstances disconnect, when the modify more than the limit of tolerance deviation, mobile terminal Applications re-connection to server, then past the statement of update through GPRS, and update local date according to the statement the other updated timestamp order, to maintain data consistency. Secondly, when the number of mobile terminals requested synchronization operation with the server at the same time online, use the priority algorithm of mobile terminals cache weighting, to determine the largest cache weighting of mobile terminals first synchronization with the server, avoid someone mobile terminal caused the backlog because unable to get synchronization. Finally, when the mobile terminal synchronization with the server, may be there conflict of inserted,modify and delete, according to various types of conflict, and use different strategies of the reconciliation and the rollback to solve these conflicts, in order to improve the accuracy of data submitted and the updating data success rate.This article also used the mobile database synchronization model in application about "Power Patrol Task System", by the synchronization mechanisms, to effectively solved the Weak consistency question between power patrol computer terminals and server, gained preferably results.