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)
20
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21
Index

Examples of query tuning

In the previous section, you learned how EXPLAIN can show the plan PostgreSQL will use to access the underlying data; it is now time to use EXPLAIN to tune some slow queries and improve performance.

This section will show you some basic concepts of the day-to-day usage of EXPLAIN as a powerful tool to determine where and how to instrument PostgreSQL in accessing data faster. Of course, query tuning is a very complex subject and often requires repeated trial-based optimization, so the aim of this section is not to provide you with in-depth knowledge about query tuning but rather a basic understanding of how to improve your own database and queries.

Sometimes, tuning a query involves simply rewriting it in a way that is more comfortable for – or better, more comprehensible to – PostgreSQL, but most often, query tuning means using an appropriate index to speed up access to the underlying data.

One important thing to take into account...