Fig. 4

Flow chart of the database operation – registration of a saved data file. If the user decides to save the currently open file, the corresponding ID_file number is removed from the “OPEN FILES“ registry. jMRUI saves the file and automatically computes the hash sum of the new file. The computed hash sum and the newly generated ID_file are inserted in the table FILES, and the ID_file of the original file is saved in the column child. The new ID_file of the saved file is added to the registry “OPEN FILES”. The file saving operation is recorded in table ACTIONS by adding a new entry with with its actions column set to “SAVE”