Chapter 1. Advanced SQL
This book is all about an open source software product, a relational database called PostgreSQL. PostgreSQL is an advanced SQL database server, available on a wide range of platforms. The purpose of this book is to teach database developers the fundamental practices and techniques to program database applications with PostgreSQL.
In this chapter, we will discuss the following advanced SQL topics:
- Creating views
 - Understanding materialized views
 - Creating cursors
 - Using the 
GROUP BYclause - Using the 
HAVINGclause - Understanding complex topics such as subqueries and joins