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