To perform data search from a multiphase viewpoint in a circumstance where a multidimensional database if only one partitioning key is used all data is to be subject of searching. Also, the improvement of the same is dependent on the system configuration of hardware. The partitioning table is defined by specifying a partitioning condition for each of respective partitioning keys to simultaneously specifying a plurality of storage areas of multi-dimension made of a combination of these partitioning ranges. From the partitioning definition information stored in the dictionary table on the same layer, the storage area to be searched may be narrowed to the least necessary even when any partitioning key value is specified as the search condition.