Define candidate key, alternate key, composite key?
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Answer Posted / deependra kumar shukla
Candidate key:- A key 'X' is said to be candidate key if proper subset of 'X' is not a key where X is simple or composite key.
Alternate key:- A candidate key is said to be Alternate key if it is not defined as primary key.An Alternate key may accept null values.
Composite key:- A key is said to be composite key if it contain more than one atribute of the relation.
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