The Type 2 Dimension/Effective Date Range mapping filters source rows based on user-defined comparisons and inserts both new and changed dimensions into the target. Changes are tracked in the target table by maintaining an effective date range for each version of each dimension in the target. In the Type 2 Dimension/Effective Date Range target, the current version of a dimension has a begin date with no corresponding end date.
Use the Type 2 Dimension/Effective Date Range mapping to update a slowly changing dimension table when you want to keep a full history of dimension data in the table. An effective date range tracks the chronological history of changes for each dimension.
When you use this option, the Designer creates the following additional fields in the target:
For each new and changed dimension written to the target, the Integration Service uses the system date to indicate the start of the effective date range for the dimension.
For each dimension being updated, the Integration Service uses the system date to indicate the end of the effective date range for the dimension.
The Integration Service generates a primary key for each row written to the target.