A method manages a database system that includes a first database device whose memory content in a storage area is changed based on a command designated through a network from any business terminal device, and a second database device for storing the same memory content as the first database device as a backup. The method makes the first database device execute: creating and storing a logical log that correlates a command content with a memory content in the storage area every time the process is executed; creating a physical log that correlates a position information about the portion that is changed by the process, the memory content after changing by the process, and a class of the process every time the process is executed; and storing command specifying information that specifies the command corresponding to the physical log with the corresponding physical log every time each physical log is created.