Combines all rows of the left-specified table reference to all
    rows of the right-specified table reference in the result. A
    cross join is a Cartesian product between two table references. A
    cross join is similar to the basic join expression but without
    the WHERE clause. This is also called a Cartesian product.
    Following is an example of the basic join expression using the
    comma-separated syntax:

    SQL> SELECT *
    cont>   FROM TABLE1, TABLE2;

    Using the CROSS JOIN clause, the previous example would appear as
    follows:

    SQL> SELECT *
    cont>   FROM TABLE1 CROSS JOIN TABLE2;