Simulating ETL Projects Interactively

Start and simulate an ETL project interactively.

1. To start a simulation, click Start on the toolbar:

   • All components of the project are initialized.

   • All connections within the project are validated.

   • All preprocessing SQL statements in the projects are executed.

   • Data for all static lookup components is retrieved and cached. Any change of data in lookup tables during simulation is not reflected in the simulation process.

2. Select a component and click the Step icon on the toolbar to execute the component.

   “Stepping a component” means executing or processing a single component. The data records that are processed during a single step are the records currently populating the IN-ports of the component.

   If a component is stepped multiple times and no other components are stepped in between, the number of records received or forwarded remains constant. Many components can be stepped from both inside the component and outside in the project view.

3. View the data flow on the connecting link or within the component.

   • To view data throughout transformation, examine the link between components or the ports of a component. Other components such as the Data Calculator and the Data Splitter include built-in preview capabilities.

   • To view data on the connecting link, right-click and select Preview.

   • To view data currently at the port, right-click the port, and select Preview.

     Note:

     The Preview option is disabled when there are no processed records or when no simulation data is available.

   • To view data from inside the component, double-click the component, or click the Rule icon in the Property window. Use this option to see the impact of transformation rules from within components, such as the Data Calculator or the Data Splitter.

4. Modify and initialize the component.

   After you modify a component, you can reinitialize the component to continue simulating the data flow. You need not restart a complete simulation for the current project.

   1. Double-click the component to modify its properties in the Properties window.
   2. Save the changes.
   3. Right-click the component and select Initialize.
5. When all data has been processed, select one of:

   • Execute Post-Processing as for successful execution – to commit all tasks performed by the transactional components and to reset the project to its initial state.

   • Execute Post-Processing as for failed execution – to rollback all tasks performed by the transactional components and to reset the project to its initial state.

   Click Yes to confirm resetting of the interactive trace. This clears all port buffers, releases temporary tables, and closes all database connections and temporary files.

   If you click No, all open database connections and port buffers are retained. You can inspect, reconfigure, and then restep individual components.

   To reset trace to commit or roll back data for the transactional components, click Reset on the toolbar, or select Run > Reset. Click Yes to confirm.

• Setting the Trace Delay
  You can control the simulation rate by setting the simulation interactive trace delay option.
• Viewing Current Mappings
  The Mapping Definition window shows the current mapping between attributes of adjacent input structures and output structures.
• Managing Port Attributes
  You can add and delete port attributes, or modify the settings or existing attributes in the Structure Viewer window.
• Viewing a Simulation Flow
  View a simulation flow.
• Controlling Multiple Data Streams
  Set up a single project that has multiple unconnected data streams. You cannot predict the order in which the streams are processed. In general, most projects consist of a single stream of components connected through links.