Chapter 13. Understanding the INFORMATION_SCHEMA
WHAT'S IN THIS CHAPTER?
What tables exist in the
How to retrieve information on your schemas and tables
How to list core MySQL metadata used for database objects
How to retrieve instrumentation on a running MySQL instance
The ANSI Standard SQL (e.g, SQL:2003 and SQL:2008) defines the support for a level of database metadata using the concept of
INFORMATION_SCHEMA. MySQL starting with version 5.0 has implemented the
INFORMATION_SCHEMA, often referred to as I_S, to provide a level of SQL access to information previously found in the popular but not SQL standard
SHOW commands. The metadata is a form of data dictionary that provides the user access to various information including database objects such as
VIEWS; schema metadata such as
CHARACTER_SETS; and internal MySQL operations including
This chapter steps through the
INFORMATION_SCHEMA tables from versions 5.0, 5.1, and the 5.4 alpha release. It also gives an example of the
INFORMATION_SCHEMA extensions possible using the InnoDB Plugin 1.0.4 and greater, which is available separately and now included in MySQL starting with version 5.1.38.
USING THE INFORMATION_SCHEMA
SHOW command can be used to retrieve information from the
INFORMATION_SCHEMA tables. As you can see, this 5.1 schema contains a number of tables, which are discussed in detail in this chapter: ...