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
Other Books You May Enjoy
21
Index

Basic concepts behind PITR

Point in Time Recovery, usually written as PITR, is a technique that allows you to restore your database at a specific point in the past. Showing you how to use PITR is out of the scope of this chapter, and this section only explains the basic concepts behind the technique.

PITR can be achieved only by means of physical backup, and it is usually performed via specific backup tools like the aforementioned pgBackRest, even though PostgreSQL provides all the needed infrastructure to perform PITR.

The main idea behind PITR is to start with a physical backup and then continuously store the database WAL segments, a process called WAL archiving. The WALs can be stored locally or sent to a remote machine, usually a specific backup machine. The need to archive all the WALs is that, as already explained in Chapter 11, PostgreSQL recycles the WALs once the modified data is safely stored on the disk; therefore, in order to get a continuous stream of WALs, the...