The bitmap index advantages on the data warehouses

Abstract

The data warehouse designer should consider the effectiveness of the data query while the selection of relevant indexes and their combination with materialized views, this, because the data query is the only way to get this information from a data warehouse. The index selection is considered an NP-complete problem, because of the number of indexes is exponential in the total attributes in the data warehouse tables. So, the choose of the suitable index type is considered as the main step to start the data warehouse design. In this paper we are making a comparison study between the B-tree index as traditional index type, and the Bitmap index. this comparison are based on three factors : index size, clustering factor and compression, and we illustrate this with a real experiment.