Instruction
Well done! We have one more question for you.
Exercise
Find the average fuel cost rounded to two decimal places for the following grouping combinations:
year,month, anddayyearandmonthyearcar_sizeandtrip_typecountry
Show also the general average fuel cost.
Assume a fuel price of $0.98 per liter. Show the following columns in the query result: year, month, day, car_size, trip_type, country, and avg_fuel_cost.
Stuck? Here's a hint!
Use GROUP BY GROUPING SETS with a ROLLUP inside:
GROUP BY GROUPING SETS ( ROLLUP (A, B, C), (D, E), (F) )



