Art Tennick has worked in relational database design and SQL queries for more than 20 years. He has been involved in multi-dimensional database design, cubes, data mining, DMX, and MDX for 10 years. Art is the author of Practical MDX Queries for Microsoft SQL Server Analysis Services 2008 and Practical PowerPivot & DAX Formulas for Excel 2010. His website is www.MrCube.net.