Book Image

MySQL 5.1 Plugin Development

Book Image

MySQL 5.1 Plugin Development

Overview of this book

MySQL has introduced a Plugin API with its latest version – a robust, powerful, and easy way of extending the server functionality with loadable modules on the fly. But until now anyone wishing to develop a plugin would almost certainly need to dig into the MySQL source code and search the Web for missing bits of the information.This is the first book on the MySQL Plugin API. Written together with one of the Plugin API primary architects, it contains all the details you need to build a plugin. It shows what a plugin should contain and how to compile, install, and package it. Every chapter illustrates the material with thoroughly explained source code examples.Starting from the basic features, common to all plugin types, and the structure of the plugin framework, this book will guide you through the different plugin types, from simple examples to advanced ones. Server monitoring, full-text search in JPEG comments, typo-tolerant searches, getting the list of all user variables, system usage statistics, or a complete storage engine with indexes – these and other plugins are developed in different chapters of this book, demonstrating the power and versatility of the MySQL Plugin API and explaining the intricate details of MySQL Plugin programming.
Table of Contents (16 chapters)
MySQL 5.1 Plugin Development
Credits
About the Authors
About the Reviewer
Preface

Chapter 4. Information Schema Plugins

The Information Schema was introduced in MySQL 5.0 as a standard way of providing database metadata accessible using normal SELECT queries. To make this work the metadata is made available via read-only tables in a database called INFORMATION_SCHEMA. In the MySQL mailing lists these tables are often informally referred to as I_S tables. The name of the schema, names of tables, and their structure is defined in the SQL standard (ISO/IEC 9075-11:2003 part 11). However, MySQL extends the standard by providing more tables than the standard dictates. This is where plugins come into the game. There is an Information Schema plugin type in MySQL 5.1. Plugins of this type can add new tables to the INFORMATION_SCHEMA database. These plugins are great for exposing information (possibly a lot of it) to the user in tabular form. Often these plugins are not distributed as standalone, but accompany other plugins, for example, complex storage engines, and expose their...