Running total

For example, running total of sum (sal + comm) department wise on emp table :

Oracle in Sqlplus:

break on deptno skip 1

select 
    deptno, 
    empno, 
    sum(sal+nvl(comm,0)) over (partition by deptno order by empno) running_total
from
    scott.emp
order by
    deptno, 
    empno;

DEPTNO      EMPNO  RUNNING_TOTAL
---------- ---------- ----------
        10       7782       2450
                 7839       7450
                 7934       8750

        20       7369        800
                 7566       3775
                 7788       6775
                 7876       7875
                 7902      10875

        30       7499       1900
                 7521       3650
                 7654       6300
                 7698       9150
                 7844      10650
                 7900      11600