Can you explain what the concept of an ordered index in databases means?

A ordered index in a database is a data structure that stores keys in sorted order. This allows efficient execution of search operations, range queries, and sorting without additional processing. For example, B-trees are often used to implement ordered indexes, enabling quick lookup of records by key and retrieving data in sorted order.

Advantages of an ordered index:

• Fast key-based search
• Efficient execution of range queries (e.g., all records with keys between A and B)
• Support for sorting without additional overhead

Example: if you have a table of users and an index on the "age" field, an ordered index will allow you to quickly find all users aged between 20 and 30.