About the Series ...
This is the sixteenth article 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 needed for getting the most out of the
lessons included, please see the first article, MDX at
First Glance: Introduction to MDX Essentials.
Note: Service Pack 3 updates are assumed for MSSQL
Server 2000, MSSQL Server 2000 Analysis Services, and the related Books
Online and Samples.
What We Accomplished in our Last Article
In the last article of
the series, Basic Set
Functions: The Except() Function,
we explored the useful Except() function, whose purpose is to return the
difference between two sets. In addition to discussing the purpose and
operation of the Except() function, we focused on the treatment of
duplicates by the function. We examined the syntax surrounding its uses, and
illustrated its application in practice exercises, providing hands-on exposure
to the use of Except().
We first undertook a
multi-step example in which we exposed default handling of duplicates by the
function, then explored an additional example where we practiced the use of the
ALL flag to override the Except() function's default duplicate
handling. Throughout the practice exercises, we discussed the results we
obtained with each step's execution, remarking on the distinguishing
characteristics of optional flag settings.
this lesson, we will expose what many consider one of the most useful functions
in the MDX arsenal, the Filter() function. The general purpose of the Filter()
function is to allow us to filter out parts of a set that we do not need in a
given situation, and to return a subset of a larger set as a result. Uses of
the Filter() function, as with many MDX functions, can range from the
sublimely simple to the impressively advanced, and it can be used in many
innovative ways. The objective, of course, is the support of precise analysis
to meet our business needs. We will see in this article how the Filter()
function is a prime example of the efficiency and precision we can attain by using
judiciously chosen functions from our MDX toolsets.
with an introduction to the Filter() function, this lesson will include:
- an examination of the syntax surrounding the function;
- illustrative examples of the uses of the function in practice
- a brief discussion of the MDX results we obtain in the