To understand PostgreSQL, you need to see it in use. An empty database is like a ghost town without houses.
For now, we will assume that you already have a database. There are over a thousand books on how to design your own database from nothing. So, here, we aim to help people who are still learning to use the PostgreSQL database management system with handy routines to explore the database.
The best way to start is by asking some simple questions to orient yourself and begin the process of understanding. Incidentally, these are also questions that you'll need to answer if you ask someone else for help.
In this chapter, we'll cover the following recipes:
- What type of server is this?
- What version is the server?
- What is the server uptime?
- Locating the database server files
- Locating the database server's message log
- Locating the database's system identifier
- Listing databases on the database server
- How many tables are there in a database?
- How much disk space does a database use?
- How much disk space does a table use?
- Which are my biggest tables?
- How many rows are there in a table?
- Quickly estimating the number of rows in a table
- Listing extensions in this database
- Understanding object dependencies