MSSQL Server Reporting Services : Mastering OLAP Reporting: Drilling Through Using MDX
October 20, 2005
About the Series ...
This article is a member of the series MSSQL Server Reporting Services. The series is designed to introduce MSSQL Server Reporting Services ("Reporting Services"), with the objective of presenting an overview of its features, together with many tips and techniques for real-world use. For more information on the series, as well as the hardware / software requirements to prepare for the exercises we will undertake, please see my initial Database Journal article, A New Paradigm for Enterprise Reporting.
As I have stated since the charter article of the series, published about the time Reporting Services was first publicly released, my conviction is that Reporting Services will commoditize business intelligence, particularly in its role as a presentation component within an integrated Microsoft BI solution. Having been impressed from my first exposure to this exciting application, when it was in early beta, my certainty in its destiny grows stronger by the day, as I convert formerly dominant enterprise business intelligence systems, such as Cognos, Business Objects, Crystal, and others, to the Reporting Services architecture. I receive constant requests to conduct strategy sessions about these conversions with large organizations in a diverse range of industries the interest grows daily as awareness of the solution becomes pervasive. Indeed, the five- to six-plus figures that many can shave from their annual IT budgets represent a compelling sweetener to examining this incredible toolset.
Basic assumptions underlying the series are that you have correctly installed Reporting Services, including current service packs, along with the applications upon which Reporting Services relies, and that you have access and the other rights / privileges required to complete the steps we undertake in my articles. For details on the specifics of the adjustments necessary to quickly allow full freedom to complete the exercises in this and subsequent articles, as well as important assumptions regarding rights and privileges in general, please see earlier articles in the series, as well as the Reporting Services Books Online.
About the Mastering OLAP Reporting Articles ...
One of the first things that become clear to "early adopters" of Reporting Services is that the "knowledgebase" for OLAP reporting with this tool is, to say the least, sparse. As I stated in my article, Mastering OLAP Reporting: Cascading Prompts, the purpose of the Mastering OLAP Reporting subset of my Reporting Services series is to focus on techniques for using Reporting Services for OLAP reporting. In many cases, which I try to outline in my articles at appropriate junctures, the functionality of the reporting solutions of well-established, but expensive, solutions, such as Cognos PowerPlay, can be met in most respects by Reporting Services at a tiny fraction of the cost. The vacuum of documentation in this arena, to date, represents a serious "undersell" of Reporting Services from an OLAP reporting perspective. I hope to contribute to making this arena more accessible to everyone, and to share my implementation and conversion experiences as the series evolves. In the meantime, rest assured that the OLAP potential in Reporting Services will be yet another reason that the application "commoditizes" Business Intelligence.
For more information about the Mastering OLAP Reporting articles, see the section entitled "About the Mastering OLAP Reporting Articles" in my article Ad Hoc TopCount and BottomCount Parameters.
In my MDX Essentials series at Database Journal, I recently published an article entitled Drilling Through with MDX: The DRILLTHROUGH Statement, where I introduced drillthrough concepts, and then focused on the use of the DRILLTHROUGH statement within MDX. Nowhere is the concept of drillthrough more practical than within a reporting application, and Reporting Services naturally leads the report writer universe in enabling us to fully leverage MDX in reporting from Analysis Services data sources.
As I mentioned in Drilling Through with MDX: The DRILLTHROUGH Statement, practically anyone involved in business intelligence is aware that multidimensional databases contain aggregated information to support rapid query processing. The beauty of OLAP (Online Analytical Processing) is that it stores high-level summaries for virtually instant delivery to our reports and other applications summaries that can, indeed, be assembled directly from an OLTP (Online Transactional Processing) system, but only after it goes through the work of summing what might be millions (or more) transactions to get the same results.
The downside to the otherwise superior reporting scenario of OLAP lies within its very advantage: aggregation. An important consideration within the realm of business intelligence is the provision of the capability of selective focus. More specifically, within the context of this article, the enterprise often needs to be able to see the underlying transactions once he or she identifies a summary that raises questions. An example might exist in the case of a real estate portfolio manager who notes, while looking at monthly performance metrics for a group of properties, that profit margins for a given property within the group seem consistently lower than the rest, or perhaps that, over a three-year period, a property's monthly profit has gradually trended lower, while others remain stable. Because transactional data is not contained within the OLAP cube, the manager needs a mechanism to present the underlying transactions (in this case, the revenues and expense transactions) that make up the margins under examination. This mechanism, to which the business intelligence community refers as drillthrough, allows the property manager to see the transactions that make up the margins, exposing, for example, the tenants, vendors, services, and other entities involved within each, so that focused action can be taken to ultimately control results.
The natively supported drillthrough of MSSQL Server Analysis Services is manifested in the retrieval and return of the underlying source's individual records the "details" that combine to make up the value of the cell upon which drillthrough is performed. As we saw in Drilling Through with MDX: The DRILLTHROUGH Statement, drillthrough from a client application can be accomplished, in the most straightforward approach, through the passage of the MDX DRILLTHROUGH statement to Analysis Services. Drillthrough can mean different things in Reporting Services. The term "drillthrough" can be used to describe two approaches to "drilling through":
In this article, we will explore using the latter of the two approaches, and leverage the DRILLTHROUGH statement that we introduced in Drilling Through with MDX: The DRILLTHROUGH Statement. As a part of our discussion, we will: