3.44 What is a referential integrity constraint? Define the term, and give an

three.44 What is a referential integrity constraint? Define the time period, and give an instance of its use. Are null values allowed in overseas key columns with a referential integrity constraint? How does the referential integrity constraint contribute to database integrity?

three.45 Clarify the position of referential integrity constraints in normalization.

three.46 Do relations StudID_SocialSecurityNumber and SocialSecurityNumber_StudName include a transitive dependency?

three.47 In normalization instance three, why is the EXTENDED_PRICE relation “foolish”?

three.48 In normalization instance four, underneath what situations is the purposeful dependency (StudentID, Exercise) S ActivityFee extra correct than Exercise S ActivityFee

three.49 If a determinant is a part of a candidate key, is that adequate for BCNF?

three.50 In normalization instance 5, why are the following two tables not right? DEPARTMENT (Division, DeptBudgetCode, Purchaser) SKU_DATA_4 (SKU, SKU_Description, Division)

three.51 How does a multivalued dependency differ from a purposeful dependency?

three.52 Think about the relation: PERSON (Identify, Sibling, ShoeSize) Assume that the following purposeful dependencies exist: Identify S S Sibling Identify S ShoeSize Describe deletion, modification, and insertion anomalies for this relation.

three.53 Why is BCNF known as the better of the varieties?

three.54 Think about the relation: PERSON_2 (Identify, Sibling, ShoeSize, Interest) Assume that the following purposeful dependencies exist: Identify S S Sibling Identify S ShoeSize Identify S S Interest Describe deletion, modification, and insertion anomalies for this relation.

three.55 What should we all know with a view to discover purposeful dependencies in a desk?

three.56 What is a multivalued dependency?

three.57 How do the situations for DK/NF correspond to the situations for BCNF