Book Image

PostgreSQL 16 Administration Cookbook

By : Gianni Ciolli, Boriss Mejías, Jimmy Angelakos, Vibhor Kumar, Simon Riggs
5 (1)
Book Image

PostgreSQL 16 Administration Cookbook

5 (1)
By: Gianni Ciolli, Boriss Mejías, Jimmy Angelakos, Vibhor Kumar, Simon Riggs

Overview of this book

PostgreSQL has seen a huge increase in its customer base in the past few years and is becoming one of the go-to solutions for anyone who has a database-specific challenge. This PostgreSQL book touches on all the fundamentals of Database Administration in a problem-solution format. It is intended to be the perfect desk reference guide. This new edition focuses on recipes based on the new PostgreSQL 16 release. The additions include handling complex batch loading scenarios with the SQL MERGE statement, security improvements, running Postgres on Kubernetes or with TPA and Ansible, and more. This edition also focuses on certain performance gains, such as query optimization, and the acceleration of specific operations, such as sort. It will help you understand roles, ensuring high availability, concurrency, and replication. It also draws your attention to aspects like validating backups, recovery, monitoring, and scaling aspects. This book will act as a one-stop solution to all your real-world database administration challenges. By the end of this book, you will be able to manage, monitor, and replicate your PostgreSQL 16 database for efficient administration and maintenance with the best practices from experts.
Table of Contents (15 chapters)
13
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14
Index

Killing a specific session

Sometimes, the only way to let the system continue as a whole is by surgically terminating some offending database sessions. Yes, you read that right: surgically.

In this recipe, you will learn how to intervene, from gracefully canceling a query to brutally killing the actual process from the command line.

How to do it…

Once you have figured out the backend you need to kill, try to use pg_cancel_backend(pid), which cancels the current query, though only if there is one. This can be executed by anyone who is a member of the role whose backend is being canceled.

If that is not enough, then you can use pg_terminate_backend(pid), which kills the backend. This works even for client backends that are idle or idle in a transaction.

You can run these functions as a superuser, or if the calling role is a member of the role whose backend pid is being signed (look for the usename field in the pg_stat_activity view).

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