About the Series …
This article is a member of the series, MDX Essentials.
The series is designed to provide hands-on application of the fundamentals of
the Multidimensional Expressions (MDX) language, with each tutorial
progressively adding features designed to meet specific real-world needs.
For more information about the series in general, as well as
the software and systems requirements for getting the most out of the lessons
included, please see my first article, MDX at
First Glance: Introduction to MDX Essentials.
Note: Current updates are assumed for MSSQL
Server, MSSQL Server Analysis Services, and the related Books
Online and Samples.
Overview
In this article, we will examine the TopCount() function,
whose highest value lies in its capability to enable us to isolate best
performers from among hundreds or thousands of fellow members. This ranking
capability is critical in data analysis and decision support scenarios: In many
business situations, we seek to report upon "best performers" for
various reasons. TopCount() facilitates our doing so, allowing us to
sort on a numeric value expression that we can provide. We can tell the
function how many "top" members we wish to retrieve (say, the "top
ten," or the "top twenty"), for a "custom-fit" approach,
that matches our needs precisely.
In
this article, we will introduce and overview the TopCount() function. We
will first comment upon the general operation of TopCount(), and then we
will:
- Examine the syntax surrounding the function;
-
Undertake illustrative examples of the rudimentary uses of the
function in practice exercises; -
Briefly discuss the results datasets we obtain in the practice
examples.
