MDX Set Functions: The ToggleDrillState() Function
May 1, 2006
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.
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: