As you saw in the last Transformation, once the data is created in the first step, it travels from step to step through the hops that link those steps. The hop's function is just to direct data from an output buffer to an input one. The real manipulation of data, as well as the modification of a stream, by adding or removing fields, occurs in the steps. In the last Transformation that you created, you used the Calculator step to create new fields and add them to your dataset.
The Calculator step is one of the many steps that PDI has to create new fields. You create the fields from scratch or by combining existent ones. Usually, you will find these steps under the Transform category of ...
