Book Image

Learn PostgreSQL - Second Edition

By : Luca Ferrari, Enrico Pirozzi
1 (2)
Book Image

Learn PostgreSQL - Second Edition

1 (2)
By: Luca Ferrari, Enrico Pirozzi

Overview of this book

The latest edition of this PostgreSQL book will help you to start using PostgreSQL from absolute scratch, helping you to quickly understand the internal workings of the database. With a structured approach and practical examples, go on a journey that covers the basics, from SQL statements and how to run server-side programs, to configuring, managing, securing, and optimizing database performance. This new edition will not only help you get to grips with all the recent changes within the PostgreSQL ecosystem but will also dig deeper into concepts like partitioning and replication with a fresh set of examples. The book is also equipped with Docker images for each chapter which makes the learning experience faster and easier. Starting with the absolute basics of databases, the book sails through to advanced concepts like window functions, logging, auditing, extending the database, configuration, partitioning, and replication. It will also help you seamlessly migrate your existing database system to PostgreSQL and contains a dedicated chapter on disaster recovery. Each chapter ends with practice questions to test your learning at regular intervals. By the end of this book, you will be able to install, configure, manage, and develop applications against a PostgreSQL database.
Table of Contents (22 chapters)
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Index

Managing extensions

Every extension is managed at a database level, meaning that every database that needs an extension must manage such an extension life cycle. In other words, there is no per-cluster way of managing an extension and applying it to every database within the cluster.

Extensions are mainly managed by three SQL statements: CREATE EXTENSION, DROP EXTENSION, and ALTER EXTENSION, to respectively install an extension in a database, remove the extension from the database, and modify extension attributes or upgrade them.

Every extension is specified by a mnemonic and a version; if a version is not specified, PostgreSQL assumes you want to deal with the latest available version or the one that is already installed.

In the following subsections, each of the three management statements will be explained.

Creating an extension

The CREATE EXTENSION statement allows you to install an existing extension in the current database.

The synopsis of the statement...