1  –  CASCADE

    Specifies that you want SQL to delete all other definitions
    (constraints, indexes, modules, storage maps, triggers, and
    views) that refer to the named table and then delete that
    table definition. This is known as a cascading delete. For
    stored routines or triggers with a routine or language-semantic
    dependency, SQL also marks the affected routines and triggers as
    invalid.

2  –  IF_EXISTS

    Prevents SQL command language from displaying error messages if
    the referenced object does not exist in the database.

3  –  RESTRICT

    Specifies that you want SQL to delete only the named table
    definition. If constraints, modules, triggers, or views are
    defined that refer to the named table, SQL does not delete the
    table. If there are indexes or storage maps that refer to the
    named table, SQL deletes the table and storage map and does not
    issue an error.

4  –  table-name

    Specifies the name of the table definition you want to delete.