The defining characteristic of a B+tree is that interior nodes only store keys, not values. The "+" does not mean that leaves are linked together - they may be

The defining characteristic of a B+tree is that interior nodes only store keys, not values. The "+" does not mean that leaves are linked together - they may be but that's not a requirement. LMDB is a B+tree but it doesn't link leaf pages together. http://en.wikipedia.org/wiki/B-tree http://en.wikipedia.org/wiki/B-tree