Chapter 7 Data Transformations Basics

Modeling Data Transformations

You can model a data transformation in PowerDesigner by:

• Creating each transformation object individually (see the Building Data Transformation Diagrams and the Building Transformation Control Flows Diagrams chapters).
• Using a Wizard (see Creating a data transformation with the Transformation Wizard and Creating a data transformation with the Convert Mappings to ETL Wizard).

We recommend that you:

1. Identify any input and output sources. These may be existing PDMs, XSMs, BPMs and flat files or live data sources that can be reversed engineered.
2. Create an ILM and launch one of the following wizards to create your basic transformation environment:
   
   
   • Transformation Wizard – see Creating a data transformation with the Transformation Wizard.
   • Convert Mappings to ETL Wizard [for existing PDM mappings] – see Creating a data transformation with the Convert Mappings to ETL Wizard.
3. Open the created data transformation diagram(s), and specify any other necessary transformation objects, such as data query executions, calculators, etc. (see the Building Data Transformation Diagrams chapter).
4. [optional] Create a control flow diagram to detail the order in which a series of data transformation tasks is executed (see the Building Transformation Control Flow Diagram chapter).

You can use the completed model to guide you in writing a transformation for your ETL engine.

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