Question

In a B+ tree, the requirement of at least half-full (50\%) node occupancy is relaxed for which one of the following cases?

• A. Only the root node
• B. All leaf nodes
• C. All internal nodes
• D. Only the leftmost leaf node

Hint:

In a B+ tree, the root node is exempt from the minimum occupancy rule, but all other nodes must maintain at least 50% occupancy.

Answer 1

The Correct Option is A

Step 1: Define the conditions for node occupancy in a B+ tree.
In a B+ tree, all nodes except the root must maintain at least 50\% occupancy to ensure the balanced structure of the tree. Step 2: Identify the exception.
The root node is an exception to the occupancy rule. It is allowed to have fewer keys, including only one key, during operations such as deletions. Final Answer: \[ \boxed{\text{Only the root node}} \]