Professional SQL Server™ Analysis Services 2005 with MDX

3.6. MDX Functions

MDX functions can be used in MDX expressions or in MDX queries as you carve up axis dimensions like a Thanksgiving turkey. MDX forms the bedrock of Analysis Services 2005; BIDS builds MDX expressions that typically include MDX functions to retrieve data from the Analysis Services database based upon your actions like browsing dimensions or cubes. MDX functions help address some of the common operations that are needed in your MDX expressions or queries. Including ordering tuples in a set, counting the number of members in a dimension, and string manipulation required to transform user input into corresponding MDX objects.

This section splits the MDX functions into various categories and provides some basic examples. The best way to learn MDX functions is to understand their use in business scenarios so that you can apply the right MDX function in analogous cases. In this book, you will often see MDX which the product generates; paying attention to and experimenting with such MDX is critical to your transition from basic understanding of Analysis Services 2005 to complete mastery — and though it is a profound challenge, mastery is attainable. You can do it. Again, when you slice a dimension in any cube-viewing software, like Office Web Components, it is MDX that is generated and executed to back-fill the newly exposed cells. Also, when you create a report based on a cube (UDM) using Excel (to be seen in Chapter 15) or using Reporting Services (Chapter 17) it ...