In a given relationship R, if an attribute A uniquely defines all other attributes, then the attribute A is a key attribute which is also known as the _________ key.
A. Candidate
B. Join
C. Functional
D. None of the Mentioned
Answer:A
In a given relationship R, if an attribute A uniquely defines all other attributes, then the attribute A is a key attribute which is also known as the _________ key.
A. Candidate B. Join C. Functional D. None of the Mentioned
Explanation: A candidate key is a column, or set of columns, in a table that can uniquely identify any database record without referring to any other data. Each table may have one or more candidate keys.