Simulating a project is a highly interactive process that lets you monitor and validate your transformation process step by step. In contrast to executing a project, you can view the data during a simulation at any stage of the transformation process. During the final steps of a simulation, data is written into the data sinks. Many transformation components (such as the Data Calculator) allow you to change transformation rules and sample values on-the-fly to validate your rule base for all potential content.
A project can only be simulated after all components
have been properly initialized.
The basic functions of a simulation consist of the following high-level steps:
Start a simulation
Step through a component
View the data flow on the connecting Link or within the component
Modify and re-initialize the component to continue to simulate the data flow
In simulation, at a more detailed level, you can:
View data content on connecting links
View input data and output data inside a component
Modify properties or calculations on-the-fly, so that you can change transformation rules and sample values to validate your rule base
Re-step a component after modifying a calculation or property
Perform “what-if” scenarios
Take multiple steps through the project
Click Start to start a simulation. When you click Start:
All components of the project become initialized.
All connections within the project are validated.
All pre-SQL statements in the projects are executed.
All data for all static Lookup components are retrieved and cached. Any change of data in lookup tables that happens while the project is simulated is not reflected in the simulation process.
Select a component and click Step to execute the component.
Stepping a component means to execute or process a single component with the data that is currently available at its input ports. The data records that are being processed during a single step are the records currently populating the IN-port 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.
View the data flow on the connecting link or within the component.
To view data throughout the transformation process, you can examine the link between components or the ports of a component. There are also components with built-in preview capabilities, such as the Data Calculator and the Data Splitter.
To view data on the link, right-click the connecting link and select Preview from the pop-up menu.
To view data currently at the port, right-click the port and select Preview from the pop-up menu.
Some components, such as the Data Calculator or the Data Splitter, allow you to see the impact of transformation rules from within the component. To view data from inside the component, double-click the component, or click Rule in the Property section.
Modify and initialize the component.
After you modify a component and decide not to restart a complete simulation for the current project, you can re-initialize the component to continue simulating the data flow.
To modify and initialize a component:
Select the component and modify its properties.
Save the modifications.
Right-click the component and select Initialize from the pop-up menu.
To simulate a project