Using Slowly Changing Dimensions - SAS Data Integration Studio 3.3 User's Guide - page 198

Figure 12.2 Type 2 SCD Columns in the Customer Dimension Table

The previous diagram shows that customer John Smith has changed his home address
three times. This information, coupled with other data in other columns (such as age
and frequency of purchase), can be used in analyses. One such analysis could determine
if Mr. Smith was a good candidate for a marketing campaign.

SCD and SAS Data Integration Studio

Transformations That Support SCD
SAS Data Integration Studio provides the following transformations that can be used
to implement slowly changing dimensions:
Type 2 SCD Loader
loads dimension tables, detects changes, tracks changes, and generates integer key
values. Generated key values give the target a primary key that is not dependent
on the business key in the source. For more information, see “About the SCD Type
2 Loader Transformation” on page 199. See also “Example: Using Slowly
Changing Dimensions” on page 204.

Lookup
loads source data into fact tables using key values from dimension tables. When
dimension tables are loaded beforehand, and when the dimension tables contain
newly generated primary key columns, the Lookup transformation efficiently pulls
those generated key columns into the fact table to maintain referential integrity.
The lookup process uses the latest hashing techniques for optimal performance.
Exception handling enables selective responses to missing values and missing
tables. WHERE-clause filtering is available to cleanse lookup table data.
Fact Table Lookup
loads source data into fact tables using key values from dimension tables, in a
manner that is similar to the more recent Lookup transformation. Use Fact Table
Lookup instead of Lookup when you want to create and save a lookup table that
you can use in subsequent transformations or jobs.

Key Effective Date
updates dimension tables based on changes to the business key, when change
detection is unnecessary.