In a database management system using a shared-nothing architecture and adopting a system takeover in a DB storage area unit, correspondence information is provided which indicates a relation between a DB storage area and a DB processing server in charge of an access to the DB storage area, when a takeover occurs to some DB storage area, the correspondence information is changed in such a manner that an access process to the DB storage area is made in charge of another running DB processing server, and when some DB storage area is accessed in response to an inquiry request from a user, a DB processing server as an access request destination is determined by referring to the correspondence information.