Book Image

PostgreSQL 14 Administration Cookbook

By : Simon Riggs, Gianni Ciolli
5 (1)
Book Image

PostgreSQL 14 Administration Cookbook

5 (1)
By: Simon Riggs, Gianni Ciolli

Overview of this book

PostgreSQL is a powerful, open-source database management system with an enviable reputation for high performance and stability. With many new features in its arsenal, PostgreSQL 14 allows you to scale up your PostgreSQL infrastructure. With this book, you'll take a step-by-step, recipe-based approach to effective PostgreSQL administration. This book will get you up and running with all the latest features of PostgreSQL 14 while helping you explore the entire database ecosystem. You’ll learn how to tackle a variety of problems and pain points you may face as a database administrator such as creating tables, managing views, improving performance, and securing your database. As you make progress, the book will draw attention to important topics such as monitoring roles, validating backups, regular maintenance, and recovery of your PostgreSQL 14 database. This will help you understand roles, ensuring high availability, concurrency, and replication. Along with updated recipes, this book touches upon important areas like using generated columns, TOAST compression, PostgreSQL on the cloud, and much more. By the end of this PostgreSQL book, you’ll have gained the knowledge you need to manage your PostgreSQL 14 database efficiently, both in the cloud and on-premise.
Table of Contents (14 chapters)

Pushing users off the system

Sometimes, we may need to remove groups of users from the database server for various operational reasons. Let's learn how to do this.

How to do it…

You can terminate a user's session with the pg_terminate_backend() function, which is included with PostgreSQL. This function takes the PID, or the process ID, of the user's session on the server. This process is known as the backend, and it is a different system process from the program that runs the client.

To find the PID of a user, we can look at the pg_stat_activity view. We can use it in a query, like this:

SELECT pg_terminate_backend(pid)
FROM pg_stat_activity
WHERE ...

There are a couple of things to note if you run this query. If the WHERE clause doesn't match any sessions, then you won't get any output from the query. Similarly, if it matches multiple rows, you will get a fairly useless result – that is, a list...