Keys of Relations K is a superkey for relation R if K functionally determines all of R. ● K is a key for R if K is a superkey,but no proper subset of K is a superkey. (minimality) 1010 Keys of Relations z K is a superkey for relation R if K functionally determines all of R. z K is a key for R if K is a superkey, but no proper subset of K is a superkey. (minimality)