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


In this chapter, we covered the topic of triggers and rules. We explored rules and triggers using some identical examples. We established that rules are simple event handlers and triggers are complex event handlers.

We introduced the concept of trigger variables:

  • NEW
  • OLD
  • TG_OP

As well as data-manipulation-based triggers, we briefly introduced the PostgreSQL event triggers that allow developers and database administrators to have more control over firing and executing functions.

We have come to understand that triggers are extremely complex event handlers. In this chapter, we started to show the power of these tools made available to the PostgreSQL DBA; in the next chapter, we will talk about partitioning and we will utilize the topics covered in this chapter.

In the next chapter, we will return to talking about triggers and we will use triggers to create a certain type of partitioning present in PostgreSQL.