Database managing method and system having data backup function and associated programs

摘要

A backup method is provided for backing up a data base of an additional storage type that added data is not updated and deleted. An attribute of data update refusal, i.e., an attribute of only data reference permission is set to each storage area in which a table is stored. It is judged for each storage area that a file once backed up is not necessary to be backed up again. Data stored in the storage area and backed up as the collective backup or divisional backup is not backed up again. The backup time can therefore be shortened.