SCD3 – store something, if not everything!
To implement SCD3 using wizard, perform the following steps:
In the designer, navigate to Tools | Mapping Designer | Mapping | Wizard | Slowly Changing Dimensions, as shown in the following screenshot:
A new window will pop up, asking you the name (
m_SCD3) of the new SCD mapping. Also, select the type of SCD you wish to implement. Select Type 3 Dimension - keep the current and previous value in the target, as we are implementing SCD3, and click on Next.
The next screen will ask you to select the source. Select a source from the dropdown. We are using
EMP_FILE.txtas the source file for our reference. We will name the target asEMPLOYEE_SCD3in this book for our reference. Then, click on Next.
In the next window, select
EMPLOYEE_IDas Logical Key Field. Also, addLOCATIONunder Fields to compare the changes and click on Next.
In the next window, select the target columns that you wish to compare in order to detect changes. In our case, the
LOCATIONcolumn...