Book Image

PostgreSQL High Performance Cookbook

By : Chitij Chauhan, Dinesh Kumar
Book Image

PostgreSQL High Performance Cookbook

By: Chitij Chauhan, Dinesh Kumar

Overview of this book

PostgreSQL is one of the most powerful and easy to use database management systems. It has strong support from the community and is being actively developed with a new release every year. PostgreSQL supports the most advanced features included in SQL standards. It also provides NoSQL capabilities and very rich data types and extensions. All of this makes PostgreSQL a very attractive solution in software systems. If you run a database, you want it to perform well and you want to be able to secure it. As the world’s most advanced open source database, PostgreSQL has unique built-in ways to achieve these goals. This book will show you a multitude of ways to enhance your database’s performance and give you insights into measuring and optimizing a PostgreSQL database to achieve better performance. This book is your one-stop guide to elevate your PostgreSQL knowledge to the next level. First, you’ll get familiarized with essential developer/administrator concepts such as load balancing, connection pooling, and distributing connections to multiple nodes. Next, you will explore memory optimization techniques before exploring the security controls offered by PostgreSQL. Then, you will move on to the essential database/server monitoring and replication strategies with PostgreSQL. Finally, you will learn about query processing algorithms.
Table of Contents (19 chapters)
PostgreSQL High Performance Cookbook
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Customer Feedback
Preface

Stopping the server in an emergency


In this recipe, we will show you the command that can be used to stop the server in an emergency situation.

How to do it...

We can use the following command to stop the PostgreSQL server in an emergency:

pg_ctl -D /var/lib/pgsql/9.6/data stop -m immediate

Here, the data directory location is defined at /var/lib/pgsql/9.6/data.

How it works...

The moment the immediate stop mode is used with the pg_ctl command, all the users have their transactions aborted and the existing connections are terminated. There is no system checkpoint either and the database basically requires crash recovery at the time of database restart.

In this shutdown mode, the PostgresSQL process will issue a direct SIGQUIT signal to each of the child processes, by including the backend processes such as bgwriter, autovacuum, and recovery processes. However, in smart shutdown mode, the PostgreSQL process will wait until these processes are terminated and then shut down the postmaster process...