Disclosed herein is a dynamic update cube and hybrid query search method for range-sum queries. The present invention relates to a hybrid query search method, which provides a precise answer or an approximate answer with respect to On-Line Analytic Processing (OLAP) queries by using a delta (.DELTA.)-tree, which has a multidimensional index structure and a prefix-sum cube, so as to effectively support range-sum queries widely used in opinion decisions in enterprises. In the dynamic update cube and hybrid query search method for range-sum queries, a prefixed-sum cube is dense and the dynamic update cube is sparse, such that whenever a data cube changes, the prefixed sum cube is not directly updated and instead, the changes of the data cube are stored in a .DELTA.-Tree and the .DELTA.-Tree is managed.