Book Image

PostgreSQL 11 Administration Cookbook

By : Simon Riggs, Gianni Ciolli, Sudheer Kumar Meesala
Book Image

PostgreSQL 11 Administration Cookbook

By: Simon Riggs, Gianni Ciolli, Sudheer Kumar Meesala

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 11 allows you to scale up your PostgreSQL infrastructure. This book takes a step-by-step, recipe-based approach to effective PostgreSQL administration. The book will introduce you to new features such as logical replication, native table partitioning, additional query parallelism, and much more to help you to understand and control, crash recovery and plan backups. You will learn how to tackle a variety of problems and pain points for any database administrator such as creating tables, managing views, improving performance, and securing your database. As you make steady progress, the book will draw attention to important topics such as monitoring roles, backup, and recovery of your PostgreSQL 11 database to help you understand roles and produce a summary of log files, ensuring high availability, concurrency, and replication. By the end of this book, you will have the necessary knowledge to manage your PostgreSQL 11 database efficiently.
Table of Contents (19 chapters)
Title Page
Copyright and Credits
About Packt
Contributors
Preface
Index

Temporarily preventing a user from connecting


Sometimes, you need to temporarily revoke a user's connection rights without actually deleting the user or changing the user's password. This recipe presents the ways of doing this.

Getting ready

To modify other users, you must either be a superuser or have the CREATEROLE privilege (in the latter case, only non-superuser roles can be altered).

How to do it…

Follow the steps to temporarily prevent and reissue the logging in capability to a user:

  1. To temporarily prevent the user from logging in, run this command:
pguser=# alter user bob nologin;
ALTER ROLE
  1. To let the user connect again, run the following:
pguser=# alter user bob login;
ALTER ROLE

How it works...

This sets a flag in the system catalog, telling PostgreSQL not to let the user log in. It does not kick out already connected users.

There's more…

Here are some additional remarks.

Limiting the number of concurrent connections by a user

The same result can be achieved by setting the connection limit for...