Database Reference
In-Depth Information
Figure 3-10.
Displaying dbo.Sales table data in SQL Server Management Studio
2.
Examine the data in each column to determine whether the data represents a measured
value or a descriptive value. In the data warehouse, measured values are translated into
measures, and descriptive values are translated into dimensional attributes.
3.
Close the query window by clicking the
x
on this window's tab.
The obvious measure in the sales table is the sales quantities. All other columns represent descriptive values.
These current descriptive values, such as the title_id, in and of themselves hold little meaning to most clients
using the reports. Therefore, you need to add dimensional attributes to the data warehouse in order to clarify
what items such as title_id really indicate. It is important to include these columns as dimensional keys
within your fact table.
Not
■
The term
dimensional key
defines a column used to identify an individual row of dimensional data. This is
usually used as a primary key in the dimension tables and a foreign key in the fact table. An example here is the title_id.
Reviewing the Data in the Titles Table
We need to look at the data in the various supporting tables. We take a look at the dbo.Titles table next
(Figure
3-11
).
