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 streaming replication

In this section, we will talk about replication. Why do we have to have replicas? The problem with PITR is that recovery often takes a long time before a server can be restored:

In a production environment, you often need to be able to restore the production environment as quickly as possible after a system crash. In order do this, we have to use the streaming replication technique. To make this possible, we need at least two servers, one master server and one slave server. The master server performs all the operations that will be requested by the application programs; the slave server will be available only for read operations and will have the data copied in real time.

Basic concept

The idea behind streaming replication is to copy the WAL files from the master server to another (slave) server. The slave server will be in a state of continuous recovery and it continuously executes the WAL that is passed by the master machine; in this way, the slave machine...