Book Image

Learning PostgreSQL 10 - Second Edition

Book Image

Learning PostgreSQL 10 - Second Edition

Overview of this book

PostgreSQL is one of the most popular open source databases in the world, supporting the most advanced features included in SQL standards. This book will familiarize you with the latest features released in PostgreSQL 10. We’ll start with a thorough introduction to PostgreSQL and the new features introduced in PostgreSQL 10. We’ll cover the Data Definition Language (DDL) with an emphasis on PostgreSQL, and the common DDL commands supported by ANSI SQL. You’ll learn to create tables, define integrity constraints, build indexes, and set up views and other schema objects. Moving on, we’ll cover the concepts of Data Manipulation Language (DML) and PostgreSQL server-side programming capabilities using PL/pgSQL. We’ll also explore the NoSQL capabilities of PostgreSQL and connect to your PostgreSQL database to manipulate data objects. By the end of this book, you’ll have a thorough understanding of the basics of PostgreSQL 10 and will have the necessary skills to build efficient database solutions.
Table of Contents (23 chapters)
Title Page
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Customer Feedback
Preface

View categories


Views in PostgreSQL can be categorized into one of the following categories on the basis of their usage:

  • Temporary views: A temporary view is dropped automatically at the end of a user session. If the TEMPORARY or TEMP keywords are not used, then the life cycle of the view starts with the view creation and ends with the action of dropping it.
  • Recursive views: A recursive view is similar to recursive functions in high-level languages. The view column list should be specified in recursive views. Recursion in relational databases, such as in recursive views or recursive common table expressions (CTEs), can be used to write very complex queries, specifically for hierarchical data.
  • Updatable views: Updatable views allow the user to see the view as a table. This means that the developer can perform INSERT, UPDATE and DELETE on views similar to tables. Updatable views can help in bridging the gap between an object model and a relational model to some extent, and they can help in overcoming...