The first nine chapters of this book were devoted to learning CQL's major features and how to effectively use them. Chapter 10, How Cassandra Distributes Data, explored the special issues that application developers must keep in mind when using a distributed database such as Cassandra. In Appendix A, Peeking Under the Hood, we took a look at the low-level data structures that were once part of the daily lives of Cassandra developers but now serve as an internal data structure underlying the more powerful abstractions of CQL. And, in this appendix, you learned about the tools Cassandra gives you to keep your deployment secure.

This brings us to the end of the topics we set out to cover in this book. You should now be fully prepared to take advantage of Cassandra's powerful feature set, high scalability, and resilience to failure in your own applications. You know that Cassandra is better suited to some use cases than others; when a distributed database is called for, you're prepared to use the most powerful distributed database on the planet, efficiently and productively.