Patent attributes
System extracts metadata of system committed change numbers, system change numbers for backup copies. System generates start system change numbers as minimums of committed change numbers, end system change numbers as maximums of change numbers, and identifiers for archive log backup copies. System identifies dependent system change numbers from start number to end number for backup copy. System identifies backed-up system change numbers, from start numbers to end numbers for log backup copies, which are in dependent numbers. If backed-up numbers don't include all dependent numbers, system outputs missing system change numbers. System generates start numbers, end numbers, and identifiers for new archive log backup copies, identifies new backed-up system change numbers, from start numbers to end numbers for new log backup copies, which are in missing numbers. If new backed-up numbers include all missing numbers, system stores backup copy with each log backup copy corresponding to any backed-up numbers.