One of the most important parts of a database is its data dictionary; a data dictionary contains: [Select all apply] Default values for columns The definitions of all schema objects in the database Integrity constraint information How much space has been allocated for, and is currently used by, the schema objects The names of the users Privileges and roles each user has been granted Auditing information, such as who has accessed or updated various schema objects SQL commands examples: GRANTS and REVOKES All data in PKS and FKs Conditional expressions