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

Summary

PostgreSQL has a very complex cost-based query planner and optimizer that does its best to provide the fastest access to the underlying data.

Thanks to the EXPLAIN command, database administrators can monitor queries to track down the costs and the time taken for execution, and decide on how to improve them in order to get faster results. Usually, the creation of indexes is the less intrusive choice in query tuning, and PostgreSQL has a very rich and expressive index interface that allows the creation of single-column, multi-column,and partial indexes of different types and technologies. When indexes do not suffice, query rewriting could be a possible solution to perform query tuning.

Costs used by the planner are based on statistical data that has to be kept, as much as possible, up to date. While the auto-analyze daemon aims to do this, the DBA can always rely on the manual ANALYZE command to update the statistics.

Understanding a query plan, knowing which nodes...