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

Introduction to users and groups

PostgreSQL distinguishes between users and groups of users: the former represents someone, either a person or an application, that could connect to the cluster and perform activities; the latter represents a collection of users that share some common properties, most commonly permissions on cluster objects.

In order to connect interactively or via an application to a PostgreSQL database, you need to have login credentials. In particular, a database user, a user who is allowed to connect to that specific database, must exist.

Database users are somewhat similar to operating system users: they have a username and an (encrypted) password and are known to the PostgreSQL cluster. Similarly to operating system users, database users can be grouped into user groups in order to make their management easier.

In SQL, and therefore also in PostgreSQL, the concepts of both a single user account and a group of accounts are encompassed by the concept...