A Structural Approach to Specify Data Transformations in Data Warehouses

One of the major challenges in designing a data warehouse, is to design the data transformation sub-system, which transfers data from source database to a target database. The target database usually contains summarized data derived from the various source database. The transformation requires the system to transfer data at the attribute level. Traditional process specification methods, such as DFD, Functional Decomposition, and Process Dependence Diagram, can not specify the process of finding the relationships. To overcome these problems, we propose a method called DID (Data Integration Diagram). DID is a hierarchical graphic representation system that allows users to document dependence relationships between source and target data at the attribute level. With the hierarchical representation mechanism, DID works smoothly with structural analysis methods, such as top-down, and bottom-up methods.