An attribute that belongs to neither the Parent nor
Key roles, a Regular attribute is used to support our dimensions
with additional adjectives. That is, the regular attribute allows us
to associate additional information with the dimension to support analysis of
characteristics we deem important within our respective analytical
environments. (We address Regular attributes throughout my Introduction to MSSQL Server Analysis Services
A Parent attribute is used to support the
recursive, parent-child relationships among the members of a dimension
requiring such support. Each dimension is limited to only one attribute
of this usage type. (We address parent-child dimensions within other
articles of my Introduction to MSSQL Server
Analysis Services series.)
Every dimension contains a single Key attribute.
The attribute member key serves as the link that associates its
containing dimension to a given measure group. Throughout the Analysis
Services documentation, as well as within numerous books and periodicals
based upon the subject matter, the attribute key is likened to the
primary key within a relational table: a relationship, similar to a join within
the relational world (relating two tables), is established between the dimension
and measure group(s) through the presence of the attribute key.
The attribute member key for a
representative dimension, the Geography dimension within the AdventureWorks sample cube, appears as
shown in Illustration
Illustration 1: A
Representative Key Attribute ...
Our focus within this article will be the attribute member key. The attribute member key is critical to the identification
of unique attribute members within Analysis Services. The key,
as we shall see, is specified within the KeyColumns setting, within the Source
group of a dimensions Attribute properties. (We overviewed the Source
properties in my Database Journal article Dimension
Attributes: Introduction and Overview, Part V.)
The members of an attribute in Analysis Services
can have one of two types of keys: a simple key or a composite key.
In this, the first half of this article, we will consider the characteristics
and properties of a simple key. In Part II, we will consider the
characteristics and properties of a composite key. A simple key
can be of any data type allowed within an Analysis Services database. It
must, of course, be unique, and is defined by a single value.
Before we get started working within a sample cube clone,
we will need to prepare the local environment for the practice session. We
will take steps to accomplish this within the section that follows.
Preparation: Locate and Open the Sample Basic UDM Created Earlier
In Dimensional Model Components: Dimensions Part I, we created a sample basic UDM within which to perform the
steps of the practice sessions we set out to undertake in the various articles
of this subseries. Once we had ascertained that the new practice database
appeared to be in place, and once we had renamed it to ANSYS065_Basic AS DB,
we began our examination of dimension properties. We continued with our
examination of attributes within the same practice environment, which we
will now access (as we did within Dimensional Model Components: Dimensions Part I and Dimensional Attributes: Introduction
and Overview Parts I through
by taking the following steps within the SQL Server Business Intelligence
NOTE: Please access the UDM
which we prepared in Dimensional Model Components: Dimensions Part I before proceeding with this
article. If you have not completed the preparation to which I refer in the
previous article, or if you cannot locate / access the Analysis Services
database with which we worked there, please consider taking the preparation
steps provided in Dimensional Model Components: Dimensions Part I before continuing, and prospectively
saving the objects with which you work, so as to avoid the need to repeat the
preparation process we have already undertaken for subsequent related articles
within this subseries.
and click, the SQL
Server Business Intelligence Development Studio, as appropriate.
briefly see a splash page that lists the components installed on the PC, and
then Visual Studio .NET 2005 opens at the Start page.
Close the Start
page, if desired.
-> Open from the main menu.
Services Database ... from the cascading menu, as depicted in Illustration
Illustration 2: Opening
the Analysis Services Database ...
to Database dialog appears.
the Connect to existing database radio button is selected, type the Analysis
Server name into the Server input box atop the dialog.
selector just beneath, labeled Database, select ANSYS065_Basic AS DB, as shown in Illustration 3.
Selecting the New Basic Analysis Services Database ...
settings on the dialog at default, click OK.
Server Business Intelligence Development Studio briefly reads the database from
the Analysis Server, and then we see the Solution Explorer
populated with the database objects. Having overviewed the properties of dimension
attributes in previous articles, we will continue to get some hands-on
exposure to properties for an example attribute member key, from
within our sample UDM.