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

Clustering against an index


In this recipe, we will be discussing a table reordering strategy based on an index, which will improve the query performance for a certain time.

Getting ready

In PostgreSQL, we have a utility command called CLUSTER that is like VACUUM. It will do some kind of table reorganization by acquiring access exclusive locks on the table. The CLUSTER command will create a new physical table by aligning its pages in the order of the mentioned index. An advantage of doing this is to avoid the index lookup overhead during the index scan, since the table itself is in ordered. Another benefit of doing this is removing all dead tuples from the table and index.

Note

Running the CLUSTER command during the business hours is not recommended as it will acquire the access exclusive lock, which will block the incoming queries on the table. Also, the CLUSTER operation requires an additional amount of disk space for the newly created table and indexes, which will drop the old table and its...