Designing the Data Warehouse: Key Steps and Crucial Issues

Abstract

Though designing a data warehouse requires techniques completely different from those adopted for operational systems, no significant effort has been made so far to develop a complete and consistent design methodology for data warehouses. In this paper we outline a general methodological framework for DW design discussing the relationships between the different steps and the difficulties in carrying them out. Within this framework, conceptual design is based on the Dimensional Fact Model, while logical design exploits multiple cost functions at increasing levels of detail in order to improve both the efficiency and efficacy of the algorithms. A workload is characterized in terms of data volumes and expected queries, to be used as the input of the logical and physical design phases whose output is the final scheme for the data warehouse. In particular, drill-across queries are explicitly taken into account throughout the design steps. Keywords Data warehouse, design methodology, conce...