1. A computer for use in a computer system including said computer and a storage system having at least one storage device including multiple physical storage areas for storing a database having database data, the database data of the database including component information having a reference item having plural value ranges, the database data being dividable according to value ranges of the reference item, the computer comprising: a database management system (DBMS) for managing said database; an access frequency obtaining module configured to obtain, for each value range of the reference item in the component information, an estimated access frequency for data of the component information by said DBMS; and a data allocation module configured to perform a process of data allocation to allocate, based on the obtained estimated access frequency, data of the component information divided according to the value ranges of the reference item to the physical storage areas to be stored, wherein each value range of the reference item corresponds to a database area defined and managed by said DBMS, and wherein the process of data allocation includes: obtaining a table/disk group correspondence which is information indicating a relationship between a table and disk groups including the physical storage areas that can be used to store the table, obtaining a key value-specific access frequency which is information indicating estimated access frequency to a table for a range of key values, obtaining a data allocation condition which is an access frequency-related condition that is applied when the allocation of database data is set, said data allocation condition is set by the administrator, setting data groups each being a collection of table data stored in a disk group, wherein the setting includes: setting the same number of data groups as the number of disk groups that can be used for storage of table data and allocating the table divided by key value range to each data group, calculating loads on the data groups set in the setting step, wherein a load is defined as an access frequency total with regard to the table data belonging to a data group and the calculation is performed based on the obtained key value-specific access frequency, determines whether the setting of data groups in the setting step satisfies the obtained data allocation condition, if the setting of the data groups in the setting step does not satisfy the obtained data allocation condition, then conducting again the setting and calculating steps, if the setting of the data groups in the setting step does satisfy the obtained data allocation condition, then performing disk group allocation and creating map information, wherein disk group allocation is a process in which one disk group is allocated to each of the data groups set in the setting steps, and carrying out a data allocation instruction which is a process in which the DBMS is instructed to store the table data in accordance with the map information created in the performing step.