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

Creating and managing databases

In this section, we will start by creating our first database, then we will learn how to delete a database and, finally, how to create a new database from an existing one. We will also analyze the point of view of the DBA. We will see what happens behind the scenes when we create a new database and learn some basic functions useful to the DBA to get an idea of ​​the real size of the databases.

Let's see how to create a database from scratch and what happens behind the scenes when a database is created.

Creating a database

To create the forumdb database from scratch, you will need to execute this simple statement:

CREATE DATABASE databasename
SQL is a case insensitive language, so we can write all the commands with uppercase or lowercase letters.

Now, let's see what happens behind the scenes when we create a new database. PostgreSQL performs the following steps:

  1. Makes a physical copy of the template database, template1.
  2. Assigns...