How to get max sal,ename,dname,sal,deptno from emp, dept table ?

Hi friends the above question asked by one of CMM 5 level company.Using row_number we will find the each department wise maximum salary.

Query : SELECT E.ENAME,D.DNAME,E.DEPTNO,E.SAL FROM(

SELECT E.ENAME,E.SAL,E.DEPTNO,ROW_NUMBER() OVER(PARTITION BY DEPTNO ORDER BY SAL DESC) RN

FROM EMP E) E INNER JOIN DEPT D ON E.DEPTNO=D.DEPTNO

WHERE RN=1;

The same approach using DENSE_RANK() 

Query :  SELECT E.ENAME,D.DNAME,E.SAL,E.DEPTNO FROM(

 SELECT E.ENAME,E.SAL,E.DEPTNO,DENSE_RANK() OVER(PARTITION BY DEPTNO ORDER BY SAL DESC) DR 

 FROM EMP E) E INNER JOIN DEPT D ON E.DEPTNO=D.DEPTNO WHERE DR=1;

Using rank() 

Query : SELECT E.ENAME,D.DNAME,E.SAL,E.DEPTNO FROM(
SELECT E.ENAME,E.SAL,E.DEPTNO,RANK() OVER(PARTITION BY DEPTNO ORDER BY SAL DESC) RN FROM EMP E)
E INNER JOIN DEPT D ON E.DEPTNO=D.DEPTNO WHERE RAN=1

Please comments here if you know any other methods regarding this topic.