The input table contains the data to build trees of departments, and is partitioned by department. In each partition, each row represents one employee in the department, identifying the employee by identifier and name and his or her manager by identifier. Each employee with no manager becomes the root of the department tree. The other employees in that department become children of their managers.
department | id | name | mgr_id |
---|---|---|---|
Marketing | 1 | Dave | none |
Marketing | 2 | Kim | 1 |
Marketing | 3 | Donna | 1 |
Marketing | 4 | Rob | 1 |
Marketing | 5 | Fran | 2 |
Marketing | 6 | Mark | 2 |
Marketing | 7 | Richard | 3 |
Marketing | 8 | Pat | 4 |
Marketing | 9 | Don | 4 |
Engineering | 10 | Peter | none |
Engineering | 11 | Sarah | 10 |
Engineering | 12 | Dale | 10 |
Engineering | 13 | John | 10 |
Engineering | 14 | Sophia | 15 |
Engineering | 15 | Jessy | 12 |
Engineering | 16 | Gary | 12 |
Engineering | 17 | Elizabeth | 13 |
Engineering | 18 | Richard | 13 |