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

Introducing transactions

A transaction is an atomic unit of work that either succeeds or fails. Transactions are a key feature of any database system and are what allow a database to implement the ACID properties: atomicity, consistency, isolation, and durability. Altogether, the ACID properties mean that the database must be able to handle units of work on its whole (atomicity), store data in a permanent way (durability), without inter-mixed changes to the data (consistency), and in a way that concurrent actions are executed as if they were alone (isolation).

You can think of a transaction as a bunch of related statements that, in the end, will either all succeed or all fail. Transactions are everywhere in the database, and you have already used them even if you did not realize it: function calls, single statements, and so on are executed in a transaction block. In other words, every action you issue against the database is executed within a transaction, even if you did not ask for it...