A Data Definition Language (DDL) is used to converse (more usually, to issue commands) regarding the structures in which data is or will be stored.
- CREATE - to create objects in the database
- ALTER - alters the structure of the database
- DROP - delete objects from the database
- TRUNCATE - remove all records from a table, including all spaces allocated for the records are removed
- COMMENT - add comments to the data dictionary
- RENAME - rename an object