ER and Relational Models

Question 71

In functional dependency Armstrong inference rules refers to

• Reflexivity, Augmentation and Decomposition
• Transitivity, Augmentation and Reflexivity
• Augmentation, Transitivity, Reflexivity and Decomposition
• Reflexivity, Transitivity and Decomposition

Question 72

Which of the following statements is FALSE about weak entity set?

• Weak entities can be deleted automatically when their strong entity is deleted.
• Weak entity set avoids the data duplication and consequent possible inconsistencies caused by duplicating the key of the strong entity.
• A weak entity set has no primary keys unless attributes of the strong entity set on which it depends are included
• Tuples in a weak entity set are not partitioned according to their relationship with tuples in a strong entity set.

Question 73

In RDBMS, different classes of relations are created using __________ technique to prevent modification anomalies.

• Functional Dependencies
• Data integrity
• Referential integrity
• Normal Forms

Question 74

In a relational data model, which one of the following statements is TRUE?

• A relation with only two attributes is always in BCNF.

• If all attributes of a relation are prime attributes, then the relation is in BCNF.

• Every relation has at least one non-prime attribute

• BCNF decompositions preserve functional dependencies