Why are surrogate keys favored in Clarity models over natural keys for primary keys?

• A. They provide stable, non-changing identifiers that do not depend on business data, avoid key collisions, and improve performance.
• B. They require less storage.
• C. They change when business data changes.
• D. They ensure referential integrity automatically.

Answer: (A)

Surrogate keys provide a stable identity for each row that doesn’t depend on business data. In Clarity models, using an internal, system-generated key means a record’s primary key won’t change if its attributes (like a name, code, or description) change, and it avoids the risk of key collisions that can occur with natural keys. This stability also yields performance benefits: compact, fixed-length keys make indexes smaller and joins faster, and foreign-key relationships are simpler to manage. By separating the database identity from business meaning, you gain smoother data integration and fewer cascading updates when business data evolves. Natural keys can be long, composite, or mutable, which would force updates to foreign keys and complicate maintenance. Referential integrity is still enforced through constraints, but surrogate keys make the overall design cleaner and more robust.