Superkey vs. Candidate key

sql database database-design ddl
Stan Kurilin picture Stan Kurilin · Jun 21, 2010 · Viewed 18.2k times · Source

What difference between Super and Candidate key in ERDB?

Answer

Eric Petroelje picture Eric Petroelje · Jun 21, 2010

A superkey is a set of columns that uniquely identifies a row. A Candidate key would be a MINIMAL set of columns that uniquely identifies a row. So essentially a Superkey is a Candidate key with extra unnecessary columns in it.

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