GROUPING Functions
-- It accepts a single column as a parameter and returns "1"
-- if the column contains a null value generated as part of a
-- subtotal by a ROLLUP or CUBE operation or "0" for any other value,
-- including stored null values
SELECT fact_1_id,
fact_2_id,
SUM(sales_value) AS sales_value,
GROUPING(fact_1_id) AS f1g,
GROUPING(fact_2_id) AS f2g
FROM dimension_tab
GROUP BY CUBE (fact_1_id, fact_2_id)
HAVING GROUPING(fact_1_id) = 1 OR GROUPING(fact_2_id) = 1
ORDER BY GROUPING(fact_1_id), GROUPING(fact_2_id);