Data Definition Language (DDL) Commands:

Data Definition Language (DDL) commands: 
Data Definition Language (DDL) statements are used to define the database 
structure or schema. Some examples:

    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
    RENAME    - rename an object