DIFFERENCE BETWEEN ROWNUM PSEUDO COLUMN AND ROW_NUMBER() FUNCTION ?

WHAT IS THE DIFFERENCE BETWEEN ROWNUM PSEUDO COLUMN AND ROW_NUMBER() FUNCTION?

ROWNUM is a pseudo column present in Oracle database returned result set prior to ORDER BY being evaluated. So ORDER BY ROWNUM does not work.

ROW_NUMBER() is an analytical function which is used in conjunction to OVER() clause wherein we can specify ORDER BY and also PARTITION BY columns.

Suppose if you want to generate the row numbers in the order of ascending employee salaries for example, ROWNUM will not work. But you may use ROW_NUMBER() OVER() like shown below:

SELECT name, sal, row_number() over(order by sal desc) rownum_by_sal

FROM EMPLOYEE o

name	Sal	ROWNUM_BY_SAL
Hash	100	1
Robo	100	2
Anno	80	3
Darl	80	4
Tomiti	70	5
Pete	70	6
Bhuti	60	7
Meme	60	8
Inno	50	9
Privy	50	10