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

An example of query tuning

In the previous section, you have learned how to use EXPLAIN to understand how PostgreSQL is going to execute a query; it is now time to use EXPLAIN in action to tune some slow queries and improve performance.

This section will show you some basic concepts of the day-to-day usage of EXPLAIN as a powerful tool to determine where and how to instrument PostgreSQL in doing faster data access. Of course, query tuning is a very complex subject and often requires repeated trial-based optimization, so the aim of this section is not to provide you with true knowledge about query tuning but rather a basic understanding of how to improve your own database and queries.

Sometimes, tuning a query involves simply rewriting it a way that is more comfortable – or better, more comprehensible –to PostgreSQL, but most often, that means using an appropriate index to speed up access to the underlying data.

Let's start with a simple example: we want to extract all...