Mastering OLAP Reports: Parameterizing Number of “Look Back” Periods with the MDX LastPeriods() Function, Part II

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”), presenting an overview of
its features, with tips and techniques for real-world use. For more
information on the series in general, please see my initial Database Journal article, A New Paradigm for Enterprise Reporting. For the software components, samples and tools
needed to complete the hands-on portion of this article, see BlackBelt
Administration: Linked Reports in Report Manager
, another article within this
series.

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 Analysis Services reporting with this
tool is, to say the least, sparse. As I stated in my article, Mastering
OLAP Reporting: Cascading Prompts
(where I treated the subject of cascading
parameters
for Reporting Services 2000), 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 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, even taking into consideration the
release of several books surrounding Reporting Services 2005 in
recent months, continues to represent a serious “undersell” of Reporting
Services
, from an OLAP reporting perspective. I hope to contribute
to making this arena more accessible for everyone, and to share my
implementation and conversion experiences as the series evolves. In the
meantime, we can rest assured that the OLAP potential in Reporting
Services
will contribute significantly to the inevitable commoditization of
business intelligence, via the integrated Microsoft BI solution.

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
.

Overview

As I
noted in Mastering
OLAP Reports: Parameterizing Number of “Look Back” Periods with the MDX
LastPeriods() Function, Part I
, we have focused, in several recent articles of this series,
upon various aspects of parameterization within the Reporting
Services
environment. In some cases we have supported parameterization from
structures completely contained within Reporting Services, and in others
we have created parameter (predominantly picklist) support
from within other layers of the integrated Microsoft business intelligence
solution. As many of us are aware, enterprise reporting applications
typically allow for parameterization (via what are sometimes known as
“prompts” or “parameter prompts”) to enable information consumers to quickly
find the information they need from a report. These parameters, whose
values are physically passed to an axis specification or a slicer in the dataset
query
, often act to put filters into place “on the fly;” the filters
are thus enacted when the consumer types or selects a value, or a series of
values, at run time.

We emphasized, in Part I, that, because they allow information consumers to assume a
role in guiding the delivery of information – and add a “self-serve” component
to the reporting experience – parameterization in general is a popular
topic in the forums and newsgroups of most enterprise reporting applications.
My continued application of the underlying concepts over many years within Cognos,
Crystal, Business Objects, MicroStrategy,
and a host of other, more specialized applications, has given me a great
appreciation for the opportunities that exist in the business environment for
effective parameterization. Whether the reports are to be printed,
displayed on screen, or any of the other options for production / deployment, it
is challenging to overstate the value that parameterization can add in
making the selection and delivery of enterprise data more focused and
consumer-friendly.

While
I have extended parameterization concepts into many arenas, none have captured
my attention as much as their deployment within the integrated Analysis
Services
/ Reporting Services pairing. These applications work
together to provide business intelligence in a way that is powerful and highly
flexible. As I have noted in
Part I, I often advise clients who are
attempting to locate a consultant to implement the integrated Microsoft BI
solution (composed of MSSQL Server, MSSQL Server Analysis Services,
and Reporting Services) to seek a “multidimensional architect” – a
consultant who has a good working knowledge of each of the components, and who
can determine where, among three or more possible “logical layers,” to
place which components so as to optimize the system as a whole.

NOTE: For details surrounding hands-on
approaches (as you will see, they are Legion) to the mechanics behind
supporting parameterization, (including the generation of picklists)
in Reporting Services, see these articles in
MSSQL Server
Reporting Services
series
here at Database Journal:

Throughout these articles, as well as elsewhere, we have
generated simple lists to provide virtually all we need to support parameterization
within Reporting Services and other enterprise reporting applications.
In this article, we will continue to pursue the objective we stated in Part I: We will perform a more detailed
examination of the mechanics behind parameterizing an MDX function
or more precisely, for parameterizing the variable argument within such
a function. We will illustrate the process using the popular LastPeriods()
function, which we introduced in MDX
Time Series Functions, Part I: PeriodsToDate() and Kindred Functions
(a
member of my MDX Essentials
series at Database Journal), but the same logic can be
extrapolated to many other similar MDX functions, as I have noted, and will
continue to note, in my articles.

In this article, we will continue to get hands-on exposure to
parameterizing LastPeriods() within the sample OLAP report that
we cloned in Part I. Beginning with the general
concepts, in Part I, we began our practice session by
setting up a scenario within which to work with a basic OLAP report in exposing
the steps involved in parameterizing the LastPeriods() function
specifically. We began by opening
the sample Report Server project, AdventureWorks Sample Reports,
and ascertaining connectivity of its shared Analysis Services data source.
Next, we created a clone of an existing
sample report, containing a matrix data region, with which to perform
our practice exercise.

Once we had made structural modifications to the clone report, to
further prepare for our practice exercise session, we performed a brief
overview of the MDX LastPeriods() function, discussing details of the
use we intended for the function to perform in support of the stated reporting
needs of a hypothetical client, as well as touching upon general concepts
surrounding the parameterization of MDX functions in general, and the LastPeriods()
function specifically.

In this, the second part of our article, we will:

  • Ensure the
    adequacy of the datasets, created automatically when we added query
    parameters as a last step in Part I, to support report
    parameters
    and meet business requirements;
  • Add syntax to
    the Month dataset query to enforce cascading, based upon
    the selection made for the Year parameter by an information
    consumer at runtime;
  • Leverage the
    MDX LastPeriods() function, containing index and Month parameter
    placeholders;
  • Discuss the
    interaction of the various components in supporting the runtime parameter
    that the end consumer sees;
  • Discuss the
    results obtained with the development techniques that we exploit.
William Pearson
William Pearson
Bill has been working with computers since before becoming a "big eight" CPA, after which he carried his growing information systems knowledge into management accounting, internal auditing, and various capacities of controllership. Bill entered the world of databases and financial systems when he became a consultant for CODA-Financials, a U.K. - based software company that hired only CPA's as application consultants to implement and maintain its integrated financial database - one of the most conceptually powerful, even in his current assessment, to have emerged. At CODA Bill deployed financial databases and business intelligence systems for many global clients. Working with SQL Server, Oracle, Sybase and Informix, and focusing on MSSQL Server, Bill created Island Technologies Inc. in 1997, and has developed a large and diverse customer base over the years since. Bill's background as a CPA, Internal Auditor and Management Accountant enable him to provide value to clients as a liaison between Accounting / Finance and Information Services. Moreover, as a Certified Information Technology Professional (CITP) - a Certified Public Accountant recognized for his or her unique ability to provide business insight by leveraging knowledge of information relationships and supporting technologies - Bill offers his clients the CPA's perspective and ability to understand the complicated business implications and risks associated with technology. From this perspective, he helps them to effectively manage information while ensuring the data's reliability, security, accessibility and relevance. Bill has implemented enterprise business intelligence systems over the years for many Fortune 500 companies, focusing his practice (since the advent of MSSQL Server 2000) upon the integrated Microsoft business intelligence solution. He leverages his years of experience with other enterprise OLAP and reporting applications (Cognos, Business Objects, Crystal, and others) in regular conversions of these once-dominant applications to the Microsoft BI stack. Bill believes it is easier to teach technical skills to people with non-technical training than vice-versa, and he constantly seeks ways to graft new technology into the Accounting and Finance arenas. Bill was awarded Microsoft SQL Server MVP in 2009. Hobbies include advanced literature studies and occasional lectures, with recent concentration upon the works of William Faulkner, Henry James, Marcel Proust, James Joyce, Honoré de Balzac, and Charles Dickens. Other long-time interests have included the exploration of generative music sourced from database architecture.

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