Pentaho 3.2 Data Integration Beginner's Guide

Chapter 6. Transforming the Row Set

So far, you have been working with simple datasets, that is, datasets where the each row represented a different entity (for example a student) and each column represented a different attribute for that entity (for example student name). There are occasions when your dataset doesn’t resemble such a simple format, and working with it as is, may be complicate or even impossible. In other occasions your data simply does not have the structure you like or the structure you need.

Whichever your situation, you have to transform the dataset in an appropriate format and the solution is not always about changing or adding fields, or about filtering or adding rows. Sometimes it has to do with twisting the whole dataset. ...