Serving as both a tutorial and a reference guide to the MDX (Multidimensional Expressions) query language, this book shows data warehouse developers what they need to know to build effective multidimensional data warehouses After a brief overview of the MDX language and a look at how it is used to access data in sophisticated, multidimensional databases and data warehousing, the authors move directly to providing practical examples of MDX in use New material covers changes in the MDX language itself as well as major changes in its implementation with the latest software releases of Microsoft SQL Server Analysis Services 2005 and Hyperion Essbase Also covers more advanced techniques, like aggregation, query templates, and MDX optimization, and shows users what they need to know to access and analyze data to make better business decisions