1. Field of the Invention
The present invention relates to a technology for a multiclient-support client-server type document management system.
2. Description of the Related Art
In a document management system that is used by a plurality of client Personal Computers (PC) in a network, a document management server stores therein data to be displayed in the form of a list or the like on the display screen of each client PC. Some of the client PCs may refer to a list containing the same data in the document management server. In this case, a user of a client PC is not informed in real-time of changes in attributes or status of the-data caused by another user, and is not able to carry out optimal operation on the data in the list.
For example, suppose that the document management server includes multiple storages. If a user A transfers any data stored in a storage 1 to another storage 2, a user B who is referring to a list containing the data is not aware that the data has been transferred by the user A to the storage 2 because the list referred to by the user B indicates that the data is still stored in the storage 1. Due to this, the user B performs operation on the data as it is in the storage 1.
In a technology disclosed in Japanese Patent Laid-Open Publication No 2003-337813, a client-server type document management system includes a client PC and a document management server that are connected via a network. The document management server includes a notifying unit that allows, when management contents at a server side are changed by a client PC, a document manager to easily learn the change of the management contents. In a technology disclosed in Japanese Patent Laid-Open Publication No 2003-85024, a document management program and method are applied to a server connectable to a network for updatably managing a document file in the server on a World Wide Web (WWW) system.
As described above, in a document management system that is used by multiple client PCs on a network, a document management server stores therein data to be displayed in the form of a list or the like on the display screen of each client PC. Some of the client PCs may refer to a list containing the same data in the document management server. In this case, a user of a client PC is not informed in real-time of changes in attributes or status of the data caused by another user, and is not able to carry out optimal operation on the data in the list.
One approach to the problem is to send a message, from the document management server to each client PC, informing that a client PC has transferred data in the document management server. With the message, each client PC can update the list. However, there are document management systems in which the document management server does not issue such a message or the client PC is not able to process the message issued from the document management server. Thus, there is a need of a technology for allowing each client PC to voluntarily confirm status of data in the document management server.