When performing a range query in a database, which index type is preferable: hash index or B-tree?

For range queries in a database, it is preferable to use a B-tree index.

Why:

• B-trees support ordered data, which allows efficient range searches (e.g., BETWEEN, >, <).
• Hash indexes are suitable for exact key lookups but do not support range searches, as hashing does not preserve order.

Therefore, if you need to find records within a certain range of values, a B-tree will be more efficient and appropriate.