B + tree notes is based on a curriculum in line to buy their own which summed up with their own understanding of the lesson content derived to a base on. Figure behind the blog data structures and algorithms in X with the first stage are based on the curriculum-based do notes.
Interview occasionally experience the B + tree. All in all, B + tree is an advanced data structure, meaning senior complex, complicated means to achieve a very high degree of difficulty. Not specialized algorithms to understand the application scenario, the performance characteristics of it.
If the interview is to deal directly see the final "summary" section on it.