1SELECT depname, empno, salary, avg(salary) OVER (PARTITION BY depname) FROM empsalary;
2
1 depname | empno | salary | avg
2-----------+-------+--------+-----------------------
3 develop | 11 | 5200 | 5020.0000000000000000
4 develop | 7 | 4200 | 5020.0000000000000000
5 develop | 9 | 4500 | 5020.0000000000000000
6 develop | 8 | 6000 | 5020.0000000000000000
7 develop | 10 | 5200 | 5020.0000000000000000
8 personnel | 5 | 3500 | 3700.0000000000000000
9 personnel | 2 | 3900 | 3700.0000000000000000
10 sales | 3 | 4800 | 4866.6666666666666667
11 sales | 1 | 5000 | 4866.6666666666666667
12 sales | 4 | 4800 | 4866.6666666666666667
13(10 rows)
14