Book Image

Mastering PostgreSQL 9.6

By : Hans-Jürgen Schönig
Book Image

Mastering PostgreSQL 9.6

By: Hans-Jürgen Schönig

Overview of this book

PostgreSQL is an open source database used for handling large datasets (Big Data) and as a JSON document database. It also has applications in the software and web domains. This book will enable you to build better PostgreSQL applications and administer databases more efficiently. We begin by explaining the advanced database design concepts in PostgreSQL 9.6, along with indexing and query optimization. You will also see how to work with event triggers and perform concurrent transactions and table partitioning, along with exploring SQL and server tuning. We will walk you through implementing advanced administrative tasks such as server maintenance and monitoring, replication, recovery and high availability, and much more. You will understand the common and not-so-common troubleshooting problems and how you can overcome them. By the end of this book, you will have an expert-level command of the advanced database functionalities and will be able to implement advanced administrative tasks with PostgreSQL.
Table of Contents (14 chapters)
Free Chapter
1
PostgreSQL Overview

Using stored procedures

In PostgreSQL, stored procedures can be used for pretty much everything. In this chapter, you have already learned about CREATE DOMAIN clause and so on, but it is also possible to create your own operators, type casts, and even collations.

In this section, you will see how a simple type cast can be created and how it can be used to your advantage. To define the type cast, consider taking a look at CREATE CAST clause:

test=# h CREATE CAST 
Command: CREATE CAST
Description: define a new cast
Syntax:
CREATE CAST (source_type AS target_type)
WITH FUNCTION function_name (argument_type [, ...])
[ AS ASSIGNMENT | AS IMPLICIT ]

CREATE CAST (source_type AS target_type)
WITHOUT FUNCTION
[ AS ASSIGNMENT | AS IMPLICIT ]

CREATE CAST (source_type AS target_type)
WITH INOUT
[ AS ASSIGNMENT | AS IMPLICIT ]

Using this stuff is very simple. You simply tell PostgreSQL which procedure...