So I got two relations with two common attributes. For one of those attributes, the attribute values in two of the tuples of those relations are the same, for the other they aren't.
How does my result after a natural join look like?
A B C B C D
1 2 3 2 3 4
5 6 7 6 8 9
I would join the first tuples of both relations, since there's 2/3 in both of them. What about the second tuples? There's 6/7 on the left, and 6/8 on the right.