Advantages of BTree+ over BTree [duplicate]

This question already has answers here: Closed 12 years ago.

Possible Duplicate:

B- trees, B+ trees difference

What are the advantages/disadvantages of BTree+ over BTree? When should I prefer one over other? I'm also interes开发者_StackOverflow中文版ted in knowing any real world examples where one has been preferred over other.

---

According to the Wikipedia article about BTree+, this kind of data structure is frequently used for indexing block-oriented storage. Apparently, BTree+ stored keys (and not values) are stored in the intermediate nodes. This would mean that you would need fewer intermediate node blocks and would increase the likelihood of a cache hit.

Real world examples include various file systems; see the linked article.