Data warehouses differ significantly from traditional transaction-oriented operational database applications. Indexing techniques and index structures applied in the transaction-oriented context are not feasible for data warehouses. This work develops specific heuristic indexing techniques, which process range queries on aggregated data more efficiently than those traditionally used in transaction-oriented systems. The book presents chapters on: - the state of the art in data warehouse research - data storage and index structures - finding optimal tree-based index structures - aggregated data in tree-based index structures - performance models for tree-based index structures - and techniques for comparing index structures.