Compare_Over_PartitionBy2

These two query will produce same results:

SELECT ename,empno, sal,round( AVG(sal) over ( order by deptno), 2) AGVSAL, deptno FROM emp
SELECT ename,empno,deptno, sal,round( AVG(sal) over (), 2) AGVSAL FROM emp order by deptno
Order BY clause as a final make over

Overflow:

Note: the query below did not group deptno.

SELECT ename,empno, sal,round( AVG(sal) over (), 2) AGVSAL, deptno FROM emp

Partition BY grouped deptno together, and also resembled the results with Order BY clause.

Order by clause may mimic Partition By clause.

SELECT ename,empno, sal,round( AVG(sal) over ( order by deptno), 2) AGVSAL, deptno FROM emp

SELECT ename,empno, sal,round( AVG(sal) over ( partition BY deptno), 2) AGVSAL, deptno FROM emp