Book Image

PostgreSQL Development Essentials

By : Baji Shaik
Book Image

PostgreSQL Development Essentials

By: Baji Shaik

Overview of this book

PostgreSQL is the most advanced open source database in the world. It is easy to install, configure, and maintain by following the documentation; however, it’s difficult to develop applications using programming languages and design databases accordingly. This book is what you need to get the most out of PostgreSQL You will begin with advanced SQL topics such as views, materialized views, and cursors, and learn about performing data type conversions. You will then perform trigger operations and use trigger functions in PostgreSQL. Next we walk through data modeling, normalization concepts, and the effect of transactions and locking on the database. The next half of the book covers the types of indexes, constrains, and the concepts of table partitioning, as well as the different mechanisms and approaches available to write efficient queries or code. Later, we explore PostgreSQL Extensions and Large Object Support in PostgreSQL. Finally, you will perform database operations in PostgreSQL using PHP and Java. By the end of this book, you will have mastered all the aspects of PostgreSQL development. You will be able to build efficient enterprise-grade applications with PostgreSQL by making use of these concepts
Table of Contents (17 chapters)
PostgreSQL Development Essentials
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface

Creating an extension


Extensions are one of the nice features in PostgreSQL. These were introduced in PostgreSQL 9.1. An extension is simply a bunch of SQL together in a script file. So, creating an extension loads the objects into the database. For example, a new datatype will require new functions, new operators, and probably new index operator classes. It is helpful to collect all these objects in a single package to simplify database management. PostgreSQL calls such a package an extension.

The following is the syntax to create an extension:

CREATE EXTENSION [ IF NOT EXISTS ] extension_name
[ WITH ] [ SCHEMA schema_name ]
     [ VERSION version ]
     [ FROM old_version ]

Let's take an example of creating a simple extension, pg_stat_statements, and the objects loaded by creating it:

postgres=# CREATE EXTENSION pg_stat_statements ;
CREATE EXTENSION

The functions created are as follows:

postgres=# \df pg_stat_statement*
List of functions
-[ RECORD 1 ]--------+------
 Schema            ...