RDBMS_Unit3

What is a functional dependency in a relation?

• A constraint between two attributes

• A join between two relations

• A primary key

• A foreign key

If A → B, then B is said to be:

• Functionally dependent on A

• A determinant of A

• A candidate key

• Not related

Which normal form eliminates duplicate columns from the same table?

• 1NF

• 2NF

• 3NF

• BCNF

In 1NF, what is the main requirement?

• No transitive dependencies

• No repeating groups or arrays

• No partial dependencies

• Only candidate keys

A relation is in 2NF if it is in 1NF and:

• Has a candidate key

• Has no partial dependency

• Has no multivalued attributes

• Has no foreign keys

Partial dependency exists when:

• A non-prime attribute depends on a part of the composite key

• A key depends on a non-key

• Attributes are multivalued

• A foreign key is null

Which of the following removes transitive dependencies?

• 1NF

• 2NF

• 3NF

• BCNF

A transitive dependency is a functional dependency in which:

• A depends on B, and B depends on C

• A depends on C directly

• Primary key is not present

• None of the above

What is the main difference between 3NF and BCNF?

• 3NF handles all anomalies

• In BCNF, every determinant is a candidate key

• 3NF allows partial dependencies

• BCNF allows multivalued dependencies

Which of the following is stronger than 3NF?

• 2NF

• 1NF

• BCNF

• 4NF