This chapter wraps up the topic of data transformation patterns. Most of it is devoted to querying persisted data with the help of F# query expressions. You should be able to grasp the nuances of query work distribution between in-memory collections and the network-located data engine.

We also touched the important issue of data parsing, demonstrating the handful of simple patterns that allow you to ingest arbitrary Excel files with the helping hand of F# type providers, which will be further covered in Chapter 11, F# Expert Techniques.

In the next chapter, I will concentrate on dual patterns of type specialization (augmentation) and type generalization in F#.