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

Managing extensions

Every extension is managed at a database level, meaning that every database that needs an extension must manage such an extension life cycle. In other words, there is not a per-cluster way of managing an extension and applying it to every database within the cluster.

Extensions are mainly managed by means of three SQL statements: CREATE EXTENSION, DROP EXTENSION, and ALTER EXTENSION, to respectively install an extension in a database, remove the extension from the database, and modify extension attributes or upgrade them.

Every extension is specified by a mnemonic and a version; if a version is not specified, PostgreSQL assumes you want to deal with the latest available version or the one that is already installed.

In the following subsections, each of the three management statements will be explained.

Creating an extension

The CREATE EXTENSION statement allows you to install an existing extension into the current database.

The synopsis of the statement is as follows...