1. A database management method in a database management system comprising an auxiliary storage device having a storage area for storing a database therein, the method comprising the steps of: a processing request acceptor accepts a processing request as a data query; a data operation executor analyzes the accepted processing request and executing a plurality of data operations on the basis of the analyzed result; a resource manager manages the data operations allocated to generated processes or threads; and an each-processing-request each-request resources-count determiner obtains schema definition information including information about a table structure of the database, storage arrangement information including mapping of a storage area for storing data in the database and of an area of the auxiliary storage device, mapping information of a scheme and storage arrangement, and a reference resources count, indicating a processes count or a threads count producing a predetermined performance when a processes count or a threads count is varied to the auxiliary storage device, and the each-processing-request resources count determiner calculates on the basis of the number of the auxiliary storage devices and the reference resources count and determines an upper limit of the processes or threads count used by the accepted processing request for each execution of the processing request, wherein, when data as a target of the data operations is stored in a plurality of the storage areas, the each-processing-request resources count determiner determines an upper limit in the processes or threads count on the basis of the number of the auxiliary storage devices having the data as the data operation target stored therein for each storage area, wherein the each-processing-request resources count determiner determines a sum of upper limits in the processes or threads count found for the respective storage areas as an upper limit for the entire processing request, and wherein, when an execution request of a linkage process of linking a plurality of associated data is accepted, the each-processing-request resources count determiner sets the upper limit value in the processes or threads count at a value in such a manner that the upper limit value for data later in a linkage order of the linkage process is set to be larger than the upper limit value for data earlier in the linkage order when linking data are stored in the different storage areas upon execution of the linkage process.