Final answer:
A B+-tree index includes pointers to link the leaf nodes in order to improve point query performance and improve range query performance.
Step-by-step explanation:
A B+-tree index includes pointers to link the leaf nodes in order to improve point query performance and improve range query performance. Point queries involve searching for a specific value, and the leaf node pointers help navigate directly to the requested value. Range queries involve searching for values within a specified range, and the leaf node pointers help traverse the index efficiently to find all the matching values.