Analytical SQL - Running Total - Order by without Partition By

Welcome to the third post on the series Analytical SQL. In the first two posts we studied 

1. Analytical Function without Window Clause 
2. Analytical Function Partition By

In this post we will create a report showing a running total of the complete EMP table in order of HIREDATE. To create a running total for the complete dataset, PARTITION BY is not required, we just need to add ORDER BY in OVER analytic clause

SQL> select d.deptno, d.dname, empno, ename, hiredate, sal,
  2  sum(sal) over(order by hiredate) running_total
  3  from emp e, dept d
  4  where e.deptno = d.deptno;

    DEPTNO DNAME               EMPNO ENAME      HIREDATE         SAL RUNNING_TOTAL
---------- -------------- ---------- ---------- --------- ---------- -------------
        20 RESEARCH             7369 SMITH      17-DEC-80     800.75        800.75
        30 SALES                7499 ALLEN      20-FEB-81     1600.9       2401.65
        30 SALES                7521 WARD       22-FEB-81       1250       3651.65
        20 RESEARCH             7566 JONES      02-APR-81     2975.5       6627.15
        30 SALES                7698 BLAKE      01-MAY-81     2850.3       9477.45
        10 ACCOUNTING           7782 CLARK      09-JUN-81    2450.45       11927.9
        30 SALES                7844 TURNER     08-SEP-81    1500.95      13428.85
        30 SALES                7654 MARTIN     28-SEP-81    1250.05       14678.9
        10 ACCOUNTING           7839 KING       17-NOV-81    5000.15      19679.05
        20 RESEARCH             7902 FORD       03-DEC-81     3000.6      23630.64
        30 SALES                7900 JAMES      03-DEC-81     950.99      23630.64
        10 ACCOUNTING           7934 MILLER     23-JAN-82       1300      24930.64
        20 RESEARCH             7788 SCOTT      19-APR-87    3000.55      27931.19
        20 RESEARCH             7876 ADAMS      23-MAY-87    1100.01       29031.2

As you can see in above output, data is ordered by HIREDATE, and RUNNING_TOTAL column is calculating SUM from the first row till the current row.