| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a technique capable of updating data with less communication traffic volume.SOLUTION: A difference retrieval system is a client server type system comprising a server which has a first database and manages a change history of data as versions and a client which is connected to the server via a communication line network and has a second database composed of the data and the version acquired from the server by synchronizing. The client in the difference retrieval system transmits only update notification to the server in a first network environment, and transmits updated data to the server and executes synchronization of the first database and the second database in a second network environment which is more advantageous environment for communication than the first network environment.</p> |
