Book Image

Learn PostgreSQL

By : Luca Ferrari, Enrico Pirozzi
Book Image

Learn PostgreSQL

By: Luca Ferrari, Enrico Pirozzi

Overview of this book

PostgreSQL is one of the fastest-growing open source object-relational database management systems (DBMS) in the world. As well as being easy to use, it’s scalable and highly efficient. In this book, you’ll explore PostgreSQL 12 and 13 and learn how to build database solutions using it. Complete with hands-on tutorials, this guide will teach you how to achieve the right database design required for a reliable environment. You'll learn how to install and configure a PostgreSQL server and even manage users and connections. The book then progresses to key concepts of relational databases, before taking you through the Data Definition Language (DDL) and commonly used DDL commands. To build on your skills, you’ll understand how to interact with the live cluster, create database objects, and use tools to connect to the live cluster. You’ll then get to grips with creating tables, building indexes, and designing your database schema. Later, you'll explore the Data Manipulation Language (DML) and server-side programming capabilities of PostgreSQL using PL/pgSQL, before learning how to monitor, test, and troubleshoot your database application to ensure high-performance and reliability. By the end of this book, you'll be well-versed with the Postgres database and be able to set up your own PostgreSQL instance and use it to build robust solutions.
Table of Contents (27 chapters)
Section 1: Getting Started
Section 2: Interacting with the Database
Section 3: Administering the Cluster
Section 4: Replication
Section 5: The PostegreSQL Ecosystem

Understanding roles

In Chapter 3, Managing Users and Connections, you have seen how to create new roles, a stereotype that can act both as a single user or a group of users. The CREATE ROLE statement was used to create the role, and you learned about the main properties a role can be associated with.

This section extends the concepts you have read about in Chapter 3, Managing Users and Connections, introducing more interesting and security-related properties of a role.

Just as a quick reminder, the synopsis for creating a new role is the following:

CREATE ROLE name [ [ WITH ] option [ ... ] ]

Here, an option can be indicated in a positive form, that is, associating the property with the role, or in a negative form with the NO prefix, which removes the property from the role. Some properties are not assigned to new roles by default, so you should take your time and consult the documentation of the CREATE ROLE statement in order to see what the default value is for every property. If you...