| 摘要 |
PROBLEM TO BE SOLVED: To trace back operation procedures to restore data to the original state, to restore even data changed long ago in a pinpoint form by easy operation, and to collectively restore a lot of data. SOLUTION: Each time data in a cell information file 11 is changed, a CPU 1 stores and manages data before the change and keyword information for retrieval of this data in a change history information file 12 as a change history. When keyword information is inputted as a restoration condition at a request for data restoration, the CPU retrieves keyword information meeting the condition to extract corresponding data before change and restores corresponding data in the cell information file 11 to the original state on the basis of the extracted data. |
