Fourth Normal Form (4NF) in DBMS Theory - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to identify the main requirement of Fourth Normal Form (4NF).

DBMS Theory

A relation is in 4NF if it is in Boyce-Codd Normal Form and has no [1] dependencies.

Drag options to blanks, or click blank then click option'

Atransitive

Bfunctional

Cmultivalued

Dpartial

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing multivalued dependencies with functional dependencies.

Thinking 4NF only requires BCNF.

4NF requires that there are no multivalued dependencies other than a candidate key.

2fill in blank

medium

Complete the code to describe the condition for a relation to be in 4NF.

DBMS Theory

If a relation has a multivalued dependency X ->-> Y, then X must be a [1] key for the relation.

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Acandidate

Bsuper

Cforeign

Dprimary

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing primary key instead of candidate key.

Confusing foreign key with candidate key.

In 4NF, for any multivalued dependency X ->-> Y, X must be a candidate key.

3fill in blank

hard

Fix the error in the statement about 4NF.

DBMS Theory

4NF eliminates [1] dependencies that are not functional dependencies.

Drag options to blanks, or click blank then click option'

Ajoin

Btransitive

Cpartial

Dmultivalued

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing multivalued dependencies with transitive dependencies.

Thinking 4NF deals with join dependencies.

4NF eliminates multivalued dependencies that are not functional dependencies.

4fill in blank

hard

Fill both blanks to complete the definition of 4NF.

DBMS Theory

A relation is in 4NF if it is in [1] and has no [2] dependencies except those involving a candidate key.

Drag options to blanks, or click blank then click option'

ABCNF

B3NF

Cmultivalued

Dfunctional

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing 3NF instead of BCNF.

Confusing functional dependencies with multivalued dependencies.

4NF requires the relation to be in BCNF and have no multivalued dependencies except those involving a candidate key.

5fill in blank

hard

Fill all three blanks to complete the example of 4NF violation and its resolution.

DBMS Theory

If a relation has attributes A, B, and C, and there are multivalued dependencies [1] and [2], then to achieve 4NF, decompose into relations with keys [3].

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AA ->-> B

BA ->-> C

CA

DB

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up which attributes are keys.

Not decomposing the relation to remove multivalued dependencies.

When a relation has multivalued dependencies A ->-> B and A ->-> C, it violates 4NF. Decomposing into relations with key A removes the violation.