Database Reference
In-Depth Information
3.25 Explain the difference between a candidate key and a primary key.
3.26 What is a surrogate key?
3.27 Where does the value of a surrogate key come from?
3.28 When would you use a surrogate key?
3.29 What is a foreign key? Explain the significance of the referential integrity constraint to a
foreign primary key.
3.30 The term domestic key is not used. If it were used, however, what do you think it would
mean?
3.31 What is a normal form?
3.32 Illustrate deletion, modification, and insertion anomalies on the STUDENT_ACTIVITY
relation in Figure 3-24.
3.33 Explain why duplicated data lead to data integrity problems.
3.34 What relations are in 1NF?
3.35 Which normal forms are concerned with functional dependencies?
3.36 What conditions are required for a relation to be in 2NF?
3.37 What conditions are required for a relation to be in 3NF?
3.38 What conditions are required for a relation to be in BCNF?
3.39 If a relation is in BCNF, what can we say about it with regard to 2NF and 3NF?
3.40 What normal form is concerned with multivalued dependencies?
3.41 What is the premise of Fagin's work on DK/NF?
3.42 Summarize the three categories of normalization theory.
3.43 In general, how can you transform a relation not in BCNF into ones that are in
BCNF?
3.44 What is a referential integrity constraint? Define the term, and give an example of
its use. Are null values allowed in foreign key columns with a referential integrity
constrain? How does the referential integrity constrain contribute to database
integrity ?
3.45 Explain the role of referential integrity constraints in normalization.
3.46 Why is an un-normalized relation like a paragraph with multiple themes?
3.47 In normalization example 3, why is the EXTENDED_PRICE relation “silly”?
3.48 In normalization example 4, under what conditions is the functional dependency
(StudentID, Activity) S ActivityFee
more accurate than
Activity S ActivityFee
3.49 If a determinant is part of a candidate key, is that good enough for BCNF?
3.50 In normalization example 5, why are the following two tables not correct?
DEPARTMENT ( Department , DeptBudgetCode, Buyer)
SKU_DATA_4 ( SKU , SKU_Description, Department )
3.51 How does a multivalued dependency differ from a functional dependency?
3.52 Consider the relation:
PERSON (Name, Sibling, ShoeSize)
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