What best describes a surrogate key?

A surrogate key is an artificial key created specifically to uniquely identify a record within a database table. This type of key does not have any intrinsic meaning or relationship to the actual data; rather, it is typically generated by the database (for example, an auto-incrementing integer or a unique identifier) to ensure that each record can be distinctly referenced without relying on the natural attributes of the data itself.

The use of surrogate keys can simplify relationships between tables, especially when the natural attributes (like names, dates, or other identifiers) may change over time or are not guaranteed to be unique. This makes surrogate keys valuable in maintaining data integrity and simplifying database management.

Considering this, the other options do not accurately describe the nature of a surrogate key. A surrogate key is not derived from the natural attributes of a record, it is not limited to primary keys, and while it may facilitate indexing indirectly due to the uniqueness it provides, that is not its primary purpose. The focus of a surrogate key is explicitly on its role in uniquely identifying records, which is captured accurately in the correct choice.