The following SELECT statement:
SELECT lname, serviceyrs, CUME_DIST()OVER(ORDER BY serviceyrs) FROM schooltbl GROUP BY 1,2;
returns the cumulative distribution by service years for teachers listed in schooltbl.
| lname | serviceyrs | CUME_DIST |
|---|---|---|
| Adams | 10 | 0.333333 |
| Peters | 10 | 0.333333 |
| Murray | 10 | 0.333333 |
| Rogers | 15 | 0.444333 |
| Franklin | 16 | 0.555333 |
| Smith | 20 | 0.888889 |
| Ford | 20 | 0.888889 |
| Derby | 20 | 0.888889 |
| Baker | 20 | 1.000000 |