Patent ID: 7269589

Claim:
A database management method for a database system which stores data divisionally in a plurality of storage areas, the method comprising: setting an access attribute of update to either permission or refusal for a plurality of files, and when changing the access attribute from update permission to update refusal, changing a backup attribute to designate backup; executing an update of data in response to a data update request from an application program when update requested data is for a file having an access attribute of update permission; judging the data update request as an error when the update requested data is for the file having an access attribute of update refusal; implementing a backup operation for each respective file of the plurality of files, according to: making a backup of a file when it has the access attribute of update permission; making a backup of the file when it has the access attribute of update refusal when the backup is the first backup procedure after the access attribute of the file changes from the access attribute of update permission to the access attribute of update refusal, irrespective of whether or not a content of the file has changed since a last backup of the file; and, not making a backup of the file when the backup is not the first backup procedure after the access attribute changes from the access attribute of update permission to the access attribute of update refusal.