The visual flow of the simulation as indicated by the box is straightforward in most projects; the box moves from one component to the next. However, the flow of a project simulation does not necessarily progress in only one direction; flow direction depends on the components used within the project.
Forwarding components, such as Data Calculator and Character Mapper, receive a number of records, apply transformation to those records, and forward the records. The number of records processed in a single step is determined exclusively by the number of records received from the preceding component.
Other components override previous Read Block Size settings. The Staging component works on the entire result set of the data stream, as defined with the query of the Data Source component. The component does not process and forward any data records until the entire result set is delivered to the IN-port. The Staging component uses its own Read Block Size property to resize the number of records forwarded with the next step.