Boyce-Codd Normal Form (BCNF) in DBMS Theory - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to identify a candidate key in a relation.

DBMS Theory

A candidate key is a minimal set of attributes [1] uniquely identify tuples in a relation.

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Awhere

Bthat

Cwhen

Dwhich

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'which' instead of 'that' can change the meaning.

The phrase 'a minimal set of attributes that uniquely identify tuples' correctly describes a candidate key.

2fill in blank

medium

Complete the sentence to explain BCNF condition.

DBMS Theory

A relation is in BCNF if for every functional dependency X [1] Y, X is a superkey.

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A=

B<-

C<->

D->

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<-' reverses the dependency direction.

The arrow '->' denotes a functional dependency from X to Y.

3fill in blank

hard

Fix the error in the BCNF definition.

DBMS Theory

In BCNF, every determinant [1] a superkey.

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Ais

Bare

Cbe

Dwas

Attempts:

3 left

💡 Hint

Common Mistakes

Using plural verb 'are' with singular subject.

'Determinant' is singular, so the verb must be 'is'.

4fill in blank

hard

Fill in the blank to complete the BCNF condition statement.

DBMS Theory

If a relation has a functional dependency [1], then the left side must be a superkey.

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AX -> Y

BX <- Y

CX = Y

DX <-> Y

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect symbols like '<-' or '=' for functional dependencies.

The functional dependency is represented as 'X -> Y'.

5fill in blank

hard

Fill all three blanks to complete the BCNF example code snippet.

DBMS Theory

relation = { 'attributes': ['A', 'B'], 'functional_dependencies': [('[1]', '[2]')], 'candidate_keys': ['[3]'] }

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

AA

BB

CAB

DC

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing single attributes with candidate keys which can be multiple attributes.

The functional dependency is from 'A' to 'B', and the candidate key is 'A' which uniquely identifies tuples.