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


Hopefully, this chapter was full of interesting ideas for the developer and the DBA. In this chapter, we talked about complex queries; we then saw the SELECT statement and the use of the LIKE, ILIKE, DISTINCT, OFFSET, LIMIT, IN, and NOT IN clauses. We then started talking about aggregates through the GROUP BY and HAVING clauses, and we introduced some aggregate functions, such as SUM(), COUNT(), AVG(), MIN(), and MAX().

We then talked in depth about subqueries and joins. Another very interesting set of topics covered in this chapter were the UNION, EXCEPT, and INTERSECT queries. Finally, by looking at the advanced options for the INSERT, DELETE, and UPDATE instructions, and by covering CTEs, we gave you an idea of ​​the power of the SQL language owned by PostgreSQL.

As for the concept of aggregates, in the next chapter, we will see a new way to make aggregates using windows functions. Through the use of windows functions, we will see that we are able to create all...