The CUME_DIST function returns the cumulative distribution of a row that is hypothetically inserted into a group of rows.
The schema is SYSIBM.
- An expression that specifies a row that is hypothetically inserted into a group of rows. The expression must return a value that is a built-in data type. The expression must be a constant, a variable, or a cast of a constant or variable.
- WITHIN GROUP
- Indicates that the aggregation follows the specified ordering within the grouping set.
- ORDER BY
- Specifies the order of the rows from the same grouping set that are processed in the aggregation.
- The sort key can be a column name or a sort-key-expression. If the sort key is a constant, it does not refer to the position of the output column (as in the ordinary ORDER BY clause), but it is a constant, which implies no sort key.
- Uses the values of the sort-key in ascending order.
- Uses the values of the sort-key in descending order.
- NULLS FIRST
- The ordering considers null values before all non-null values in the sort order.
- NULLS LAST
- The ordering considers null values after all non-null values in the sort order.
The number of expressions must be the same as the number of sort-key expressions. The data type of each expression and the data type of the corresponding sort-key expression must be compatible.
The data type of the result is DECFLOAT(34). The actual result is greater than 0.0 and less than or equal to 1.0.
SELECT CUME_DIST(47000) WITHIN GROUP (ORDER BY SALARY) INTO :CD FROM EMPLOYEE WHERE WORKDEPT = 'A00'