MDX in Analysis Services: Introducing DISTINCT COUNT
April 26, 2004
About the Series ...
This is the fourteenth tutorial article of the series, MDX in Analysis Services. The series is designed to provide hands-on application of the fundamentals of MDX from the perspective of MS SQL Server 2000 Analysis Services ("MSAS"); our primary focus is the manipulation of multidimensional data sources, using MDX expressions, in a variety of scenarios designed to meet real-world business intelligence needs.
For more information on the series, as well as the hardware / software requirements to prepare for the tutorials we will undertake, please see the first lesson of this series: MDX Concepts and Navigation.
Note: At the time of writing, Service Pack 3 updates are assumed for MSSQL Server 2000, MSSQL Server 2000 Analysis Services, and the related Books Online and Samples. The screen shots that appear in this article were taken from a Windows 2003 Server, and may appear somewhat different from coinciding views in other operating systems.
In our last tutorial, Named Sets in MDX: An Introduction, we introduced named sets in MDX queries, focusing on their creation through use of the WITH clause, to allow us to gain an understanding of the general capabilities of static and dynamic named sets. We introduced the concepts behind named sets, and then examined the MDX syntax required to create them and to specify them for presentation in our results. Next, we discussed the nature of static and dynamic named sets, and then activated what we had learned through an illustrative practice example for each of the two types. Finally, we discussed the results we obtained in each hands-on example, illustrating the value that named sets can offer us.
In this article, we introduce the concept of distinct counts, discussing why they are useful - indeed, often required - in our organizational analysis efforts. Throughout our session, we will describe some of the challenges that are inherent in distinct counts, and then we will undertake practice exercises to illustrate solutions to meet our business needs. As a part of the practical exercises, built around a hypothetical business need, we will provide an introduction to the approach afforded us by the MSAS user interface, and then to an alternative approach we can take using MDX.