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

Using foreign data wrappers and the postgres_fdw extension

Foreign data wrappers allow us to access data that is hosted on an external database as if it were kept in a normal local table. We can connect PostgreSQL to various data sources, we can connect PostgreSQL to another PostgreSQL server, or we can connect PostgreSQL to another data source that can be relational or non-relational. Once the foreign data wrapper is connected, PostgreSQL is able to read the remote table as if it were local. There are foreign data wrappers for well-known databases such as Oracle and MySQL, and there are foreign data wrappers for lesser-known systems. A complete list of foreign data wrappers available for PostgreSQL is available at https://wiki.postgresql.org/wiki/Foreign_data_wrappers.

In this section, we will consider an example using the postgresql_fdw foreign data wrapper, which is used to connect a PostgreSQL server to another PostgreSQL server.

If we want to use the Docker images, we...