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

Indexes

An index is a data structure that allows faster access to the underlying table so that specific tuples can be found quickly. Here, “quickly” means faster than scanning the whole underlying table and analyzing every single tuple.

PostgreSQL supports different types of indexes, and not all types are optimal for every scenario and workload. In the following sections, you will discover the main types of indexes that PostgreSQL provides, but in any case, you can extend PostgreSQL with your own indexes or indexes provided by extensions.

An index in PostgreSQL can be built on a single column or multiple columns at once; PostgreSQL supports indexes with up to 32 columns.

An index can cover all the data in the underlying table, or can index specific values only – in that case, the index is known as “partial.” For example, you can decide to index only those values of certain columns that you are going to use the most.

An index can also...