1. A device for setting cache space in a data processing system including a computer on which a database management system runs, a storage device which includes a cache and stores data in databases which the database management system manages, and administrative device which manages the computer and the storage device, wherein the computer, the storage device, and the administrative device are interconnected via a network, the device comprising: means for acquiring information about process details to be executed by the data management system; means for acquiring information about data mapping from the computer and the storage device; means for creating planned cache space settings, using the acquired information; and means for directing the storage device to activate cache space settings according to the planned cache space settings.