About the Series …
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
Note: Service Pack 3 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.
most of us that work with MSAS are aware, dimensions as defined in Analysis
Services contain many properties, one of which is the default member.
The default member can have far-reaching effects from the perspective of
information consumers, because they are often not even aware of the property, usually
cannot control it, and would not likely relish controlling it even if they
could. Yet the default member affects the results of their reporting
and analysis ambitions because it "fills in the blanks" with regard
to the setting of any unspecified dimensions in the MDX queries that they
generate, be it from enterprise reporting systems, the Pivot Table Service (for
example, within the new Excel OLAP add-in, which I plan to discuss in a
subsequent article), or through any other vehicle they use to query an MSAS
clause that lies within every MDX query (whether it is explicit or not) is the
fulcrum of the default member in reporting and analysis. In its job of
describing slicer dimensions, the WHERE clause is "subsidized"
by MSAS itself, because MSAS supplements any dimensions that the WHERE
clause leaves unspecified, and which do not appear in an axis assignment, with
the default member it derives from the dimension properties settings
inside the cube structure. All dimensions are thus accounted for, allowing for
precision in the data retrieval from the OLAP cube.
member, by default, is typically the All level for a given
dimension, unless the "default" empty state of the property is
changed. If the property is empty and there is no All level in place for
the dimension, the default member is an assigned member inside the
highest level of the dimension.
of the setting of the default member property, its use in the WHERE
clause of MDX queries is not often clear to information consumers, many of
which understand little more about MultiDimensional eXpressions than how to
spell "MDX." I constantly encounter cases where those who query
cubes do not realize that all dimensions are specified, whether they
name them or not, and that the impact of MSAS’ "assumptions" can affect
the outcome of the results they obtain in their querying efforts.
becomes particularly noticeable with the Time dimension(s), which, as in
the sample cubes that accompany MSAS, is typically without an All level
in its structure(s). The effects of the default member within the Time
dimension are likely to have to be managed in most business environments.
While we can certainly maintain the default member manually, from an
administrative perspective, this only adds overhead to our already
article, we will explore one approach to enhancing the behavior of the default
member. We will:
existing default member setting for the dimension
simple solution through customization of the default member for a Time
Provide a more
elaborate solution to provide a completely dynamic default member
results we obtain from the MDX that we use to accomplish each solution.