Book Image

PostgreSQL 9 Administration Cookbook - Second Edition

Book Image

PostgreSQL 9 Administration Cookbook - Second Edition

Overview of this book

Table of Contents (19 chapters)
PostgreSQL 9 Administration Cookbook Second Edition
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Pushing users off the system


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

How to do it…

You can terminate a user's session with the pg_terminate_backend() function included with PostgreSQL. That 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.

Note

Some of the columns used in this recipe had a different name in version 9.1 and before:

  • pid was called procpid

  • query was called current_query

The queries in this recipe are written for PostgreSQL 9.4, the most recent stable version at the time of writing this book. They work without changes on versions 9.3 and 9.2. To run them on prior versions, you only have to replace each occurrence of pid with procpid and query with current_query.

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