About the Series …
This article is a member of the series, MDX
Essentials. The series is designed to provide handson
application of the fundamentals of the Multidimensional Expressions (MDX) language,
with each tutorial progressively adding features designed to meet specific
realworld needs.
Virtually all of the MDX we have constructed in earlier
articles can now be used in the SQL Server Management Studio, SQL
Server Business Intelligence Studio, and various other areas within
the Microsoft integrated Business Intelligence solution, and much of
what we construct going forward can be executed in the Analysis Services
2000 MDX Sample Application (assuming connection to an appropriate Analysis
Services 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 examine business uses of MDX in general. The use of MDX to meet the
realworld needs of our business environments will continue to be my primary
concentration within the MDX Essentials series.
For more information about the series in general, as well as
the software and systems requirements for getting the most out of its member
lessons, please see Set
Functions: The DrillDownMember() Function,
where important information is detailed regarding the applications, samples
and other components required to complete our practice exercises.
Overview
In
this article, we will continue the examination of "MDX for drilling up
and down" that we began in Set Functions: The DrillDownMember() Function. We have discussed the nature of drilling,
in general, in previous articles of our subseries, stating that it comprises
an analytical technique through which means an information consumer can
maneuver between summarized ("drilling up") and detailed ("drilling
down") levels of data. We noted that either of drilling up or drilling
down occurs along the lines of drilling paths that are defined within
the structure of our cubes, and which are typically specified by the cube’s dimensional
hierarchies. We mentioned, too, that these paths can be based upon
alternative relationships that exist within or between dimensions.
To repeat an example I have used to illustrate the general
concept, drilling down might be described 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 Adequate Yearly Progress (AYP)
data within a cube constructed primarily to allow comparison and analysis of
those results at various levels. The executive can examine national averages,
numbers of test takers, and various other measures, 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 even congressional districts), counties
/ school systems, and more. Depending upon the design of the cube, the drilldown
process could ultimately take the consumer to the level of the individual schools
– perhaps even to the individual students themselves.
Drilling up is a capability that might be taken for
granted in a drilldown scenario such as the foregoing. From any of the drilled
down levels at which the information consumer finds himself or herself, a
corresponding capability to navigate upward, from more detailed
levels of data to more summarized levels of data, would be an
expected complementary feature.
In the earlier articles, Set
Functions: The DrillDownMember() Function and Set
Functions: The DrillUpMember() Function,
we introduced the "primary," memberdirected MDX drilldown functions,
DrillDownMember() and DrillUpMember(), respectively. In this
article, we will examine a function, ToggleDrillState(), that compounds
the actions of these two functions, and whose objective, like that of most of
the other drill functions that we have examined within this series, is to serve
as a mechanism to transform the actions of information consumers, within an end
user application (at, say, the reporting layer), into a corresponding MDX
operation.
In a
manner similar to that of other functions that we have examined in the MDX
Essentials series, ToggleDrillState() can be useful in a host of
different reporting and analysis applications. Along with other "navigational"
functions like it (virtually all of which we examine in other articles of this
series) ToggleDrillState() 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. Like other MDX functions in general, the ToggleDrillState() 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
practice exercises; -
Briefly discuss the results datasets we obtain in the practice
examples.
