A
           / \
          B   C
         / \   \
        D   E   F

##</code><code>##

node_id | ancestor | distance
-----------------------------
B       | A        | 1
C       | A        | 1
D       | B        | 1
D       | A        | 2
E       | B        | 1
E       | A        | 2
F       | C        | 1
F       | A        | 2