CUME_DIST()

Relative rank (or, cumulative distribution) of a row within a window partition

Result type

DOUBLE PRECISION

Syntax

CUME_DIST () OVER <window_name_or_spec>

CUME_DIST is calculated as the number of rows preceding or peer of the current row divided by the number of rows in the partition.

In other words, CUME_DIST() OVER <window_name_or_spec> is equivalent to COUNT(*) OVER <window_name_or_spec> / COUNT(*) OVER()

select
  id,
  salary,
  cume_dist() over (order by salary)
from employee
order by salary;

Result

id salary cume_dist
-- ------ ---------
 3   8.00       0.2
 4   9.00       0.4
 1  10.00       0.8
 5  10.00       0.8
 2  12.00         1