The reporting chain above each person

Constraints

1. 1Build the path by walking down from the root, not up from each employee. Anchoring on the CEO builds every path in one pass; anchoring on each employee would need one recursion per person.
2. 2The root is the row with manager_id IS NULL. There is exactly one, and = NULL will not find it — that comparison is never true.
3. 3depth counts levels from the root, so the CEO is 1 and her direct reports are 2.
4. 4The path separator is > , with single spaces, and the path includes the employee themselves as the last element.
5. 5Return only employees at depth 4 or deeper, ordered by employee_id.

Worked example

The anchor is Ada at depth 1 with path = 'Ada Okafor'. The recursive term appends: Bo becomes Ada Okafor > Bo Lindqvist at depth 2, Eve becomes Ada Okafor > Bo Lindqvist > Eve Marsh at depth 3, and Ivy reaches depth 4. The deepest row is Vik at depth 7, whose path names six managers above him. Note where the filter goes. WHERE depth >= 4 belongs in the final SELECT, not in the recursive term — putting it inside would stop the walk before it ever reached depth 4, and return nothing at all.

What this tests

Whether you pick the cheaper direction to recurse in, and whether you know that a filter inside the recursive term prunes the walk rather than the output.