  Nowadays, information management systems deal with data originating from
different sources including relational databases, NoSQL data stores, and Web
data formats, varying not only in terms of data formats, but also in the
underlying data model. Integrating data from heterogeneous data sources is a
time-consuming and error-prone engineering task; part of this process requires
that the data has to be transformed from its original form to other forms,
repeating all along the life cycle. With this report we provide a principled
overview on the fundamental data shapes tabular, tree, and graph as well as
transformations between them, in order to gain a better understanding for
performing said transformations more efficiently and effectively.
