Which statement best describes surrogate primary keys in a data model?

Which statement best describes surrogate primary keys in a data model?

• A. Surrogate keys are natural keys derived from business data.
• B. Surrogate keys should be visible to end users and included in business reports.
• C. Surrogate keys are system-generated identifiers that do not carry business meaning and help maintain stable keys across changes.
• D. Surrogate keys duplicate business keys to improve readability.

Answer: (C)

Surrogate primary keys are artificial identifiers generated by the system to identify rows, not derived from or carrying business meaning. They stay constant even when business attributes change, which keeps joins and references stable as the data evolves. This separation between identity and business data avoids the problems of changing keys and complicated, large, or composite natural keys. Surrogate keys are typically hidden from end users and used purely to relate records; they’re not meant to convey business information. In contrast, natural keys come from real business data and can change or be unwieldy, which is why using a surrogate for the primary key is often preferable.

Surrogate primary keys are artificial identifiers generated by the system to identify rows, not derived from or carrying business meaning. They stay constant even when business attributes change, which keeps joins and references stable as the data evolves. This separation between identity and business data avoids the problems of changing keys and complicated, large, or composite natural keys. Surrogate keys are typically hidden from end users and used purely to relate records; they’re not meant to convey business information. In contrast, natural keys come from real business data and can change or be unwieldy, which is why using a surrogate for the primary key is often preferable.