What purpose do indexes serve in databases?

Indexes in databases are specialized data structures that significantly enhance the speed of data retrieval operations. When a database query is executed, the system uses indexes to quickly locate the requested data without having to scan every record in the database, which can be time-consuming, especially with large datasets.

By using indexes, the database optimizer can efficiently navigate through the data. This reduces the amount of data that must be examined, leading to faster query performance and improved response times, making it crucial for performance optimization in database management.

While indexes do not directly increase the size of the database or simplify queries in a functional sense, their purpose is specifically tied to improving the efficiency of data access. Additionally, they are not designed to secure the database from unauthorized access; security measures typically involve user authentication and access controls rather than the indexing mechanism.