The visible flow of the simulation as indicated by the box is straight forward in many projects. The box is moving from one component to the next. However, the flow of a project simulation is not necessarily heading strictly into one direction. The flow of simulation heavily depends on the components used within the project.
There are forwarding components, which receive a number of records, apply the transformation to those records, and forward those records (such as the Data Calculator and the Character Mapper). The number of records that are being processed in one single step is exclusively determined by the value of the Read Block Size property of a preceding component.
There are other components that do override the previous Read Block Size parameter. The Staging component is designed to work on the entire result set of the data stream (as defined with the Query of the Data Source component). The component will not process and forward any data records until the entire result set has been delivered to the IN-port. The Staging component resizes the amount of records forwarded with the next step by using its own Read Block Size property. See Chapter 6, “Components” for an explanation of the behavior of every component during the simulation.
