This chapter was all about indexes. You learned when PostgreSQL will decide on an index and which types of indexes exist. On top of just using indexes, it is also possible to implement your own strategies to speed up your applications with custom operators and indexing strategies.
For those of you who really want to take things to the limit, PostgreSQL offers custom access methods.
Chapter 4, Handling Advanced SQL, is all about advanced SQL. Many people are not aware of what SQL is really capable of, and therefore, I am going to show people some efficient, more advanced SQL stuff.
