Introduction to MSSQL Server 2000 Analysis Services: Derived Measures vs. Calculated Measures

About the Series …

This
article is a member of the series Introduction to MSSQL Server 2000
Analysis Services
. The series is designed to provide hands-on
application of the fundamentals of MS SQL Server 2000 Analysis Services,
with each installment progressively adding features and techniques designed to
meet specific real-world needs. 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 article, Creating Our First Cube.

Note: Service Pack 3 / 3a updates are assumed for MSSQL Server 2000, MSSQL
Server 2000 Analysis Services
, and the related Books Online
and Samples. Images are from a Windows 2003 Server
environment, upon which I have also implemented MS Office 2003, but the
steps performed in the articles, together with the views that result, will be
quite similar within any environment that supports MSSQL Server 2000 and MSSQL Server 2000 Analysis Services ("Analysis
Services"
or "MSAS"). The same is generally true,
except where differences are specifically noted, when MS Office 2000 and
above are used in the environment, in cases where MS Office components are
presented in the article.

Overview

In
dealing with MSAS implementations on a daily basis, and especially when being
called upon to tune MSAS implementations performed by others, I come across the
less-than-optimal use of calculated members quite often. As most of us
know, calculated members are dimensions or measures (depending
upon the designated parent dimension) that are constructed, using a formula,
from other dimensions or measures in our cubes. A typical example of a calculated
member that is designed for a measure, to which we will refer in this article
as a calculated measure, is a Profit calculated measure that is
created by subtracting a cost / expense measure from a sales /
revenue
measure. Another common calculated measure is a variance
measure, which is created by taking a difference between an actual and a
budgeted value (or similar kinds of values), among other approaches.

If the calculation /
formula that we use in creating the calculated measure consists of a simple
match between two measures, we can often use a derived measure instead.
In this article, we will discuss the advantages and disadvantages involved, and
compare and contrast the methods of adding these sorts of measures to our
cubes. In examining the use of derived
measures to enhance cube response times, we will:

  • Discuss the
    drawbacks in using calculated members in cases where a derived measure might be
    substituted;

  • Discuss
    benefits and disadvantages that might accrue through the use of derived
    measures;

  • Describe an
    illustrative scenario, upon which we will determine that a derived measure can
    offer a tuning solution for a group of hypothetical information consumers;

  • Implement a
    simple solution through creation of a derived measure to replace an existing calculated
    measure;

  • Explain the
    results we obtain from the steps we take to accomplish the solution.
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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