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, please see my first article, MDX at
First Glance: Introduction to MDX Essentials.
follow along with the steps we undertake within this and prospective articles
of the series, the following components, samples and tools are recommended, and
should be installed according to the respective documentation that accompanies MSSQL
Microsoft SQL Server 2005 Database Engine (for the accompanying
SQL Server Management Studio);
Microsoft SQL Server 2005 Analysis Services;
Business Intelligence Development Studio;
The Analysis Services AdventureWorks DW sample
database (fully deployed to Analysis Services from the AdventureWorks
DW Analysis Services project that accompanies Analysis Services 2005).
Server 2005 and Analysis Services 2005 samples to which I refer
above are available within a Microsoft Windows Installer package that
accompanies the respective applications on the installation CDs, or which can
be downloaded from Microsoft and perhaps elsewhere. The samples are not
installed by default. If you did not install the samples and the AdventureWorks
sample database during SQL Server 2005 Setup, you can install them
after Setup finishes. For more information, see the topic "Running
Setup to Install AdventureWorks Sample Databases and Samples" in the SQL
Server Books Online. Make sure that you read and follow the
installation instructions in the Readme files that accompany the samples
that you want to install. For a list of samples, see the topic "Samples"
in the SQL Server Books Online.
To successfully replicate
the steps of the article, you also need to be a member of the appropriate group
/ role in Analysis Services to access the sample cube for our
exercises. Read permissions are assumed for the samples upon which we
will base our practice exercises, where we will often be using the AdventureWorks
cube, which arrives with Analysis Services 2005 within the AdventureWorks
DW Analysis Services project.
Current Service Pack updates
are assumed for the operating system, MSSQL Server 2005 ("MSSQL
Server"), MSSQL Server 2005 Analysis Services ("Analysis
Services"), MSSQL Server 2005 Reporting Services ("Reporting
Services") and the related Books Online and Samples.
Images are from a Windows 2003 Server environment, but the steps
performed in the articles, together with the views that result, will be quite
similar within any environment that supports MSSQL Server 2005 and its
Within MSSQL Server Analysis Services 2000, we had
somewhat limited options (namely, the MDX Sample Application) for easily
querying our cube data sources with MDX (at least, that is, options that
were available "out of the box" to anyone who had simply installed Analysis
Services and its samples). MSSQL Server 2005 offers us numerous
means for querying our OLAP data sources. In the interest of working within the
current environment, in this and the prospective articles of the series, we
will construct and execute our MDX queries, in the most part, from the SQL
Server Management Studio, but we will occasionally do so from the SQL
Server Business Intelligence Studio, and perhaps from other vantage points,
to further enrich the learning experience within the subject matter involved.
For more in-depth information on any of these various "points of approach"
themselves, see the relevant sections of the Books Online.
Virtually all of the MDX we constructed in earlier articles
can now be used in the SQL Server Management Studio, SQL Server
Business Intelligence Studio, and in various other areas within the Microsoft
integrated Business Intelligence solution. In addition, much of what we
construct going forward can be executed in the MDX Sample Application (assuming
connection to an appropriate Analysis Services 2000 OLAP data source). MDX
as a language continues to evolve and expand: we will focus on many new
features in articles to come, while still continuing to consider business uses
of MDX in general. The use of MDX to meet the real-world needs of our business
environments will continue to be my primary focus within the MDX Essentials series.
article, we will continue our examination, begun in Set
Functions: The DRILLDOWNMEMBER() Function, of the MDX surrounding drilling
up and down within our Analysis Services cubes. As we have noted,
drilling up or down occurs along the lines of drilling paths that are
defined within the physical structures of our cubes, and comprises an analytical
technique by which an information consumer can maneuver between
summarized ("drilling up") and detailed ("drilling
down") levels of data. While these drilling paths are typically
defined by the cube's dimensional hierarchies, they can also be based upon
alternative relationships that exist within or between dimensions.
A general example, which I have used within sister articles
surrounding the MDX "drilling" functions, might be extended as
follows, based upon an engagement within which I have recently been involved.
An executive within a state Department of Education wishes to examine
annual Graduation Rates within a cube constructed primarily to allow
comparison and analysis of those rates at various levels. The executive can
examine national rates and numbers of graduates, and then perform a
drilldown operation within a Geography dimension that might then present
the data by states. He could then perform subsequent drilldowns to
display state regions (or perhaps congressional districts), counties
/ school systems, and more. Depending upon the design of the cube, the drilldown
process could ultimately take the information consumer to the level of the
individual schools perhaps even to the individual students
themselves (assuming a world without privacy concerns, of course).
Set Functions: The DRILLDOWNMEMBER() Function,
we discussed that, underneath the capability of Analysis Services to
meet this common need is the DrillDownMember() function. Another "staple"
support function underpinning drill down capabilities is the DrillDownLevel()
function, which will form the subject of this article. DrillDownLevel()
drills down the members of a set to a lower level, and additionally offers us
the flexibility to specify which level below a given member in the set,
as we shall see. In its simplest use, based upon a set we specify, DrillDownLevel()
returns a set of child members, each of which is included immediately under
its respective parent member. DrillDownLevel() also affords us the
option to narrow the children we return to only the members of a given level,
if that is desirable.
In addition to its default behavior of taking a set
specification as an argument, and drilling down to reveal the members of
the level underneath (where appropriate), DrillDownLevel() can
accept an additional Level argument to allow us to direct drilldown to a
specific level, instead of simply drilling to the immediately "next"
level, as we shall see. (We can alternatively supply an index to
further control the behavior of the DrillDownLevel() function in
targeting a specific level).
manner similar to other functions that we have examined in the MDX
Essentials series, DrillDownLevel() can be useful in a host of
different reporting and analysis applications. DrillDownLevel(), along with other "navigational"
functions like it (virtually all of which we examine in other articles of this
series) allows us to exercise a great deal
of presentation sleight of hand, in working with MDX in Analysis Services,
as well as within Reporting Services and various other reporting
applications that can access an Analysis Services cube.
As we have
seen to be the case with other members of the "family" of drill-related
functions, as well as with many other MDX functions in general, the DrillDownLevel() function can be leveraged, within
and among the various "layers" of the Microsoft integrated Business
Intelligence solution, to support sophisticated presentations and features. We
will introduce the function, commenting upon its operation and touching upon
examples of effects that we can employ it to deliver. As a part of our
discussion, we will:
Examine the syntax surrounding the function;
Undertake illustrative examples of the uses of the function in
Briefly discuss the results datasets we obtain in the practice