In Chapter 11, Deciding on Useful Extensions, we learned about some useful extensions that are widely adopted and that can give your deployment a real boost. Following this up, you will now be introduced to PostgreSQL troubleshooting. The idea is to give you a systematic approach to inspecting and fixing your system.

In this chapter, the following topics will be covered:

• Approaching an unknown database
• Gaining a brief overview
• Identifying the key bottlenecks
• Handling storage corruption
• Inspecting broken replicas

Keep in mind that many things can go wrong, so it is important to professionally monitor the database.