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 streaming replication

In this section, we will talk about why we have to have replicas.

Figure 17.1: Primary/Replica Schema

In a production environment, you often need to be able to restore it as quickly as possible after a system crash. In order to do this, we have to use the streaming replication technique. To make this possible, we need at least two servers, one primary server and one secondary server. The primary server performs all the operations that will be requested by the application programs; the replica server will be available only for read operations and will have the data copied in real time.

Basic concepts of streaming replication

The idea behind streaming replication is to copy the WAL files from the primary server to another (replica) server.

The replica server will be in a state of continuous recovery, and it continuously executes the WAL that is passed by the primary machine; this way, the replica machine binarily replicates the...