Introduction
Monitoring plays a crucial role in defining the server capacity or defining the health of a database server. Monitoring a database server with a certain interval will give us some useful trend information about the server functionality as per the running business. As business grow continuously, the collected trend information will define the future database server capacity. Server capacity may not be directly proportional to database performance. Since even if we have enough resources, a bug in a database engine's optimizer may drain out all the resources. Also, database performance may not be directly proportional to server capacity, since a kernel bug might cause all the resources to drain out in no time. To identify the underlying problems, monitoring trends information will be more useful. However, in this chapter, we are only covering what to monitor in PostgreSQL to check its behavior in a database server.
PostgreSQL provides a good number of catalog tables, views, and...