Patent ID: 7509317

Claim:
A file system, comprising: a processing apparatus configured to apply data processing to document data, said processing apparatus being configured to assign additional data to the document data when the document data is processed; a storage device configured to store the document data and the additional data processed and assigned by the processing apparatus; a similarity determining device configured to determine similarity of newly processed document data to the document data already processed and stored in the storage device; and a storage control device configured to associate link information with both of additional data assigned to the newly processed document data in accordance with a result of the determination of the similarity determining device, wherein said storage control device is configured to insert same link information into respective additional data assigned to the newly processed document data and the document data already processed and stored in the storage device, and to erase one of the newly processed document data and the document data already processed, when the similarity determining device determines that the newly processed document data and the document data already processed and stored in the storage device are identical.