select trunc(hired),
count(*) hired_today,
sum(count(*)) over (order by trunc(hired)) as running_total
from emp
group by trunc(hired)
http://sqlfiddle.com/#!4/4bd36/9
select trunc(hired),
count(*) hired_today,
sum(count(*)) over (order by trunc(hired)) as running_total
from emp
group by trunc(hired)
http://sqlfiddle.com/#!4/4bd36/9