2과목)다음 중 윈도우 함수에 대한 설명으로 옳지 않은 것은?

SELECT ROW_NUMBER() OVER (ORDER BY SAL) FROM EMP; SELECT RANK() OVER (ORDER BY SAL) FROM EMP; SELECT SUM(SAL) OVER (PARTITION BY DEPTNO) FROM EMP; SELECT SUM(SAL) GROUP BY DEPTNO FROM EMP;