Dimension Design - Professional SQL Server Analysis Services 2005 with MDX - page 164

Chapter 5: Dimension Design
Prior to the advent of cable, when you brought home a new television, the first
order of business was to manually tune in one of the few existing local chan-
nels. To accomplish this you manipulated the dials, rabbit-ear antennae posi-
tioning, and other controls to eventually obtain an optimal picture, audio, and
vertical hold configuration. The process of designing a data warehouse using
Analysis Services 2005 is similar to this. Analysis Services 2005 provides you
with various wizards that help you build the initial framework, just like the rotary
tuner on the television got you close to the desired channel. With the basic in-
frastructure in place, some fine-tuning can optimize the initial framework to
your needs. In fact, you saw this approach in the previous chapter when you
learned about creating data sources and DSVs. Likewise, here you learn creat-
ing dimensions using the Dimension Wizard and then using the Dimension
Designer to fine-tune the dimension based on your business needs.
Cubes are made of dimensions and measures where the measures are ag-
gregated along each dimension. Without an understanding of dimensions and
how measures are aggregated along dimensions, you can't create and exploit
the power of cubes, so let's jump right in learning about building and viewing
dimensions. Once the dimensions are created they need to be added to the
cube and the right relationship type between the fact data and dimension
needs to be defined. Analysis Services 2005 supports six relationship types
which you learn in this chapter and Chapter 8. In addition you learn the attrib-
utes and hierarchies that form an integral part of dimensions. You learn to
model the Time dimension and Parent-Child dimensions in Analysis Services
2005 which are unique from regular dimensions and quite often found in many
data warehouses. Finally, you find out how to process and browse the dimen-
sions.