25. Rollup( group by 절에 조건으로 소계값) | Cube (각 소계와 전체총계까지)

--자동으로 소계/합계를 구해주는 함수
--Rollup: group by 절에 주어진 조건으로 소계값 구해준다
select major, position, sum(pay)
from professor
group by position, rollup(major);

select major, position, sum(pay)
from professor
group by major, rollup(position);

--Cube : 각 소계와 전체총계까지 구해준다
select major, count(*), sum(pay)
from professor
group by cube(major);

select major, position, count(*), sum(pay)
from professor
group by cube(major, position);