In the context of databases, which type of index uses a separate data structure to store index key values along with pointers to the actual data rows?OptionsB-Tree IndexBitmap IndexDense IndexHash Index

The type of index that uses a separate data structure to store index key values along with pointers to the actual data rows in the context of databases is a B-Tree Index.

Here's a step-by-step explanation:

1. In a database, an index is used to speed up the retrieval of records. It works similarly to an index in a book.

2. A B-Tree index is a specific type of index that uses a tree data structure to organize its entries. The 'B' in B-Tree stands for Balanced, which means that the tree is kept balanced to optimize search times.

3. The B-Tree index stores index key values. These are the values that the index is sorting on.

4. Along with each key value, the B-Tree index also stores a pointer. This pointer leads to the actual data row in the database that the key value is associated with.

5. Therefore, when a search is performed using a B-Tree index, the database system first navigates through the B-Tree to find the key value, and then follows the pointer to quickly locate the actual data row. This process is much faster than scanning through every row in the database.

6. So, the answer to your question is B-Tree Index.