Book Image

PostgreSQL Server Programming

Book Image

PostgreSQL Server Programming

Overview of this book

Learn how to work with PostgreSQL as if you spent the last decade working on it. PostgreSQL is capable of providing you with all of the options that you have in your favourite development language and then extending that right on to the database server. With this knowledge in hand, you will be able to respond to the current demand for advanced PostgreSQL skills in a lucrative and booming market."PostgreSQL Server Programming" will show you that PostgreSQL is so much more than a database server. In fact, it could even be seen as an application development framework, with the added bonuses of transaction support, massive data storage, journaling, recovery and a host of other features that the PostgreSQL engine provides. This book will take you from learning the basic parts of a PostgreSQL function, then writing them in languages other than the built-in PL/PgSQL. You will see how to create libraries of useful code, group them into even more useful components, and distribute them to the community. You will see how to extract data from a multitude of foreign data sources, and then extend PostgreSQL to do it natively. And you can do all of this in a nifty debugging interface that will allow you to do it efficiently and with reliability.
Table of Contents (17 chapters)
PostgreSQL Server Programming
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Preface
Index

Extension versions


The version mechanism for PostgreSQL extensions is simple. Name it whatever you want and give it whatever alphanumeric version number that suits your fancy. Easy, eh? Just name the files with this format:

extension--version.sql

If you want to provide an upgrade path from one version of your extension to another, you would provide the file:

extension--oldversion--newversion.sql

This simple mechanism allows PostgreSQL to update an extension that is already in place. Gone are the days of painful exporting and re-importing data just to change the definition of a data type. So, let's go ahead and update our example extension using the file postal--1.0--1.1.sql. This update is as easy as:

ALTER EXTENSION postal UPDATE TO '1.1';

A note of caution: PostgreSQL does not have any concept of what your version number means. In this example, the extension was updated from Version 1.0 to 1.1 because we explicitly provided a script for that specific conversion. PostgreSQL did not deduce...