3rd highest salary in oracle - oracle

Question

I had been looking for the query to find the 3rd highest salary from the database (using Oracle database). I found the below query -
SELECT *
FROM
( SELECT e.*, row_number() over (order by sal DESC) rn FROM emp e
)
WHERE rn = 3;
I do not have oracle installed in my system, so I'm not try it out. But I want to know if the below query will work or not. If not, then why ?
WITH Sal_sort AS
(SELECT DISTINCT sal FROM salary ORDER BY sal DESC
)
SELECT * FROM Salary S, Sal_sort SS WHERE S.Sal = SS.Sal AND SS.rownum = 3;

Answer 1

Input Data
emp_no emp_fname emp_lname salary
1 aa bb 30
2 ee yy 31
3 rr uu 32
4 tt ii 33
5 tt ii 33
6 tt ii 33
7 tt ii 33
8 tt ii 30
9 tt ii 31
Example:
select * from ee;
select emp_no,salary ,dense_rank() over (order by salary ) dr
from ee
Output
emp_no salary dr
1 30 1
8 30 1
9 31 2
2 31 2
3 32 3
4 33 4
5 33 4
6 33 4
7 33 4

Answer 2

So much easier in version 12 of the database and higher now.
SELECT *
FROM employees
ORDER BY salary DESC OFFSET 2 ROWS FETCH NEXT 1 ROWS ONLY
Tim talks about this feature here.
And if you take a look at the plan, you can see it's not magic, the optimizer is using analytic functions to derive the results.

Answer 3

JUST ONE LINE
select * from (
select salary,dense_rank() over (order by salary desc) rank from employees) where rank=3;
or
select * from (
select a.*,dense_rank() over (order by a.salary desc) rank from employees a) where rank=3;

Answer 4

Without Dense_rank()
SELECT salary FROM employees
ORDER BY salary DESC
OFFSET 2
FETCH 1 NEXT ONE ROWS ONLY;
With Dense_rank()
SELECT salary
FROM
(
SELECT salary, DENSE_RANK() OVER (ORDER BY salary DESC) as rank from employees
)
WHERE rank = 3;