In this chapter, you learned about transactions, locking and its logical implications, and the general architecture the PostgreSQL transaction machinery can have for storage, concurrency, and administration. You saw how rows are locked and some of the features available in PostgreSQL.

In Chapter 3, Making Use of Indexes, you will learn one of the most important topics in database work: indexing. You will also learn about the PostgreSQL query optimizer, as well as various types of indexes and their behavior.