In the previous chapter, we covered a few scalability, backup, and recovery concepts. We also saw how pgpool-II can be used with PostgreSQL's streaming replication to achieve horizontal scalability with read/write separation. We had a look at point-in-time recovery with PostgreSQL's inbuilt tools.

From installation to designing databases, optimization, and scaling, we covered a lot. Unfortunately, there will be hiccups when we try something new. In this chapter, we will cover common problems we are likely to run into when we work with PostgreSQL and how to troubleshoot them. The errors/issues range from connection issues to a query that is not responding. We will start with connection issues.