Classification of transformations
At this point, we have seen quite a few transformations and their functions. Before we look at the next transformations, let's talk about the classification of transformations. Based on their functionality, transformations are divided as follows.
Active and passive
This classification of transformations is based on the number of records in the input and output port of the transformation. This classification is not based on the number of ports or the number of groups.
If the transformation does not change the number of records in its input and output ports, it is said to be a passive transformation. If the transformation changes the number of records in the input and output ports of the transformation, it is said to be an active transformation. Also, if the transformation changes the sequence of records passing through it, it is classed as an active transformation, as with Union transformations. Let's take an example to understand this classification.
Consider...