, or Information and Definition Schemas
, extension to the SQL
standard is defined by ISO
/IEC 9075-11:2003. SQL/Schemata defines the Information Schema and Definition Schema, providing a common set of tools to make SQL databases
and objects self-describing. These tools include the SQL object identifier, structure and integrity constraints, security and authorization specifications, features and packages of ISO/IEC 9075, support of features provided by SQL-based DBMS
implementations, SQL-based DBMS implementation information and sizing items, and the values supported by the DBMS implementations.