Data Analysis Expressions (DAX) is a new calculation language introduced in Microsoft SQL Server 2008 R2 within PowerPivot. DAX is an extension to the Excel formula syntax and offers information workers an intuitive yet powerful tool to add business logic to their PowerPivot applications. In SQL Server code-named “Denali”, with the introduction of the BI Semantic Model, DAX becomes a key component of any Corporate Business Intelligence application built on the Microsoft Business Intelligence stack. The goal of this session is to introduce you to the concepts in DAX, how to add calculated columns and measure to your model, and the new DAX features coming in "Denali".
For more information, check out this course on Microsoft Virtual Academy: