Surrogatkey

Surrogatkey is a term used in data management to denote a surrogate key, an artificial identifier assigned to a record in a database or data store. Unlike a natural key, which encodes business information, a surrogatkey carries no inherent business meaning and is designed to be stable over the lifetime of the record.

A surrogatkey is typically generated by the database system or an ETL process and is used as the primary key for the table. Common forms include auto-incremented integers and globally unique identifiers (GUIDs or UUIDs).

It provides stable identity even when business keys change, and simplifies joins across tables and systems, especially in data integration and warehousing scenarios.

Advantages include reliable performance of joins, isolation from changes in business data, easier handling of missing or changing natural keys, and support for slowly changing dimensions in data warehousing.

Limitations include the need to maintain a separate lookup to user-facing attributes, potential for orphaned mappings if keys are not managed properly, and governance requirements to ensure the surrogate key remains aligned with the real-world entities.

See also: surrogate key; natural key; primary key; data warehousing; slowly changing dimensions.