Alternate Key

alternate key
See Also: key
[database structures] An attribute or set of attributes in a relational database that provides a unique identifier for each record and could be used as an alternative to the primary key.

In the context of relational databases, an alternate key (or secondary key) is any candidate key which is not selected to be the primary key (PK).

See also: Primary Key, Relational Database, Attributes, Relation, Database