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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Index

Comparing logical replication and physical replication

Let’s now examine how a logical replica differs from a physical replica:

  • One of the positive characteristics of physical replicas is their speed. However, a distinct disadvantage is that we have to replicate all the databases in the cluster. Using a physical replica, it is not possible to replicate a single database belonging to an instance of PostgreSQL, and it is not possible to replicate only some tables of a database. Logical replication is a little bit slower than physical replication, but by using logical replication, we can decide which databases we want to replicate within a cluster and/or which tables we want to replicate within a single database.
  • Physical replication is only possible if the two servers have the same version of PostgreSQL. With logical replication, since the logical instruction to be executed is passed to the replica server, it is also possible to perform replications between different...