Using Slowly Changing Dimensions - SAS Data Integration Studio 3.3 User's Guide - page 195

CHAPTER

12

Using Slowly Changing
Dimensions

About Slowly Changing Dimensions

195

SCD Concepts 195
Type 2 SCD Dimensional Model 196
SCD and SAS Data Integration Studio 198
Transformations That Support SCD 198
About the SCD Type 2 Loader Transformation

199

Change Tracking Techniques 199
Selecting Columns for Change Detection 200

Generating Surrogate Keys 201
How Source Data Is Loaded a Dimension Table 202

Example: Using Slowly Changing Dimensions 204

Preparation 204
Check Out Existing Metadata That Must Be Updated 205

Create and Populate the Job 205
Add SCD Columns to the Dimension Table 206
Specify the Primary Key for the Dimension Table 207

Specify the Business Key for the SCD Loader 208

Specify the Generated Key for the SCD Loader

209

Set Up Change Tracking in the SCD Loader

210

Set Up Change Detection in the SCD Loader 211

Run the Job and View the Results 212

Check In the Metadata 213

About Slowly Changing Dimensions

SCD Concepts

A dimension is a category of contextual data or detail data that is implemented in a
data model such as a star schema. For example, in a star schema, a dimension named
Customers might associate customer data with transaction identifiers and transaction
amounts in a fact table.
A dimension table is a table that contains data about a particular dimension in a
star schema or a snowflake schema. A primary key connects a dimension table to a
related fact table. For example, if a dimension table named Customers has a primary
key column named Customer ID, then a fact table named Customer Sales might specify
the Customer ID column as a foreign key.