Database synchronization

摘要

Synchronization of data items between parties A and B. A maintains copies of data items and an A change count and a B change count for each data item. The A change count indicates the number of changes made by A, and the B change count indicates the number of changes made by B and known to A. After a synchronization trigger, A sends to B each data item that A has changed, plus the A change count and the B. change count for each sent data item. A receives from B each data item that B has changed, plus the A change count and the B change count for each received data item. A detects a conflict if the received A change count differs from the maintained A change count.

主权项

1. A method for synchronizing a first data storage and a second data storage, the method comprising:
maintaining by a processor a first change count and a second change count for a data item a first data storage, wherein the first change count maintained the processor indicates a number of changes made to the data item at the first data storage, wherein the second change count maintained by the processor indicates a number of changes made to a corresponding data item at a second data storage; and responsive to a synchronization trigger that is generated when the data item is changed and a data connection is available:
receiving an identifier for the changed data item along with a first change count and a second change count maintained at the second data storage;detecting a conflict in the data item between the first and second data storages based on the maintained first and second change counts and the received first and second change counts; andresolving the conflict according to a set of predetermined rules, wherein applicable rules of the set of predetermined rules are displayed as a menu on a user interface for selection by a user; and wherein one application is responsible for receiving the identifier for the changed data item and another application is responsible for the changes made to the data item at the first data storage.