The dimensions of many data sets have a complex-level structure in current multidimensional data ware-house models. But the data warehouse can't implement all the data at every node of these dimension levels because of the large amount of data,so it's necessary to judge whether a data request is satisfiable in a complex-level-structure multidimensional data warehouse. In this paper,a method is presented to solve this problem. The characteristics of prime number are applied.
The technology of virtual data warehouses catches more and more interests of people. In this paper,aQuery-Optimization Based Virtual Data Warehouse (QVDW)model is presented,which not only has all the advantagesthat a virtual data warehouse has,but also can change bottom layer data structures and the model itself according tousers' various query requests. The aim is to offer customized service to OLAP (on-line analysis processing)users.
