Select the statement that best defines a candidate key?

(A) An attribute or combination of attributes that allows the user to search for non-unique data
(B) An attribute or combination of attributes that is calculated from existing data
(C) An attribute or combination of attributes that establishes relationships between tables
(D) An attribute or combination of attributes that could be, but is not, used as a PK

Which of the following justifies the inclusion of derived attributes in a database?

(A) Inclusion of derived attributes is a standard procedure and does not require justification
(B) Derived attributes should be used when they add to design elegance
(C) Query speed is enhanced by not computing derived attributes
(D) Poor design is the only excuse for the inclusion of derived attributes

What is the difference between a DBMS and an RDBMS?

(A) A RDBMS uses metadata while a DBMS does not
(B) A DBMS is used for data warehousing
(C) Because a relational database is more complicated than a conventional database, the RDBMS requires much more computing power than the conventional DBMS requires
(D) Because a conventional database is less complicated than a relational database, the DBMS is used more often for transactional databases

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