QL CROSS JOIN vs FULL OUTER JOIN. As a result of the CROSS JOIN statement, a Cartesian Product is produced, and the query returns all possible combinations of all rows in two tables. CROSS JOINs don't have ON clauses as everything is joined with everything. FULL OUTER JOIN is a combination of LEFT OUTER and the RIGHT OUTER JOINs. FULL OUTER JOIN returns those rows in two tables that match the WHERE clause, and shows null values for the rows the ON condition isn't met for.