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 explored how to use window functions. We have seen that by using window functions we can create more complex aggregates compared to those made with the GROUP BY statement, which we saw in Chapter 5, Advanced Statements. We learned how to use the ROW_NUMBER (), FIRST_VALUE (), LAST_VALUE (), RANK DENSE_RANK(), LAG (), LEAD (), CUME_DIST (), and NTILE () functions. We have also seen the difference between creating aggregates with the ROWS BETWEEN and RANGE BETWEEN clauses. You can use what you have learned in this chapter in data mining operations to make your work much easier.

For more information on window functions, you can consult the official documentation:

In the next chapter, we will talk about server-side programming, we will look at how to create functions to be used on the server side and, if necessary, where to use window functions.