This chapter was all about system statistics. You learned how to extract information from PostgreSQL and how to use system statistics in a beneficial way. Without proper monitoring, achieving good and reliable operations is close to impossible. It is important to keep an eye on runtime parameters and database vitals to avoid trouble. This chapter has taught you a lot about PostgreSQL monitoring, which can be used to optimize your database.
The most important views were discussed in detail. Chapter 6, Optimizing Queries for Good Performance, which is the next chapter in this book, is all about query optimization. You will learn how to inspect queries and how they are optimized.