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.