A B+ tree can be viewed as a B-tree in which each node contains only keys (not key-value pairs), and to which an additional level is added at the bottom with linked leaves.
Sources from youtube state that the number of keys should be between [(n/2) - 1] and n-1 i.e., if n = 4, the no. of values should be between 1 and 3. But the rule from Henry Korth's book and as per our professor's class, the B+ tree rule states that the leaf node must have between [ceiling of (n-1)/2] and (n-1) keys i.e., [ceiling(1.5)] = 2 and 3 values. So, after deletion, the tree is violating the B+ tree property. It now has only 1 key. I am confused about which rule to use.
