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Home Database The Relational Model and Normalization Comments

  • Question
  • For some relations, changing the data can have undesirable consequences called:


  • Options
  • A. referential integrity constraints.
  • B. modification anomalies.
  • C. normal forms.
  • D. transitive dependencies.

  • Correct Answer
  • modification anomalies. 


  • The Relational Model and Normalization problems


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    • 1. Table is synonymous with the term:

    • Options
    • A. record.
    • B. relation.
    • C. column.
    • D. field.
    • Discuss
    • 2. In the relational model, relationships between relations or tables are created by using:

    • Options
    • A. composite keys.
    • B. determinants.
    • C. candidate keys.
    • D. foreign keys.
    • Discuss
    • 3. The primary key is selected from the:

    • Options
    • A. composite keys.
    • B. determinants.
    • C. candidate keys.
    • D. foreign keys.
    • Discuss
    • 4. If attributes A and B determine attribute C, then it is also true that:

    • Options
    • A. A ? C.
    • B. B ? C.
    • C. (A,B) is a composite determinant.
    • D. C is a determinant.
    • Discuss
    • 5. An attribute is a(n):

    • Options
    • A. column of a table.
    • B. two dimensional table.
    • C. row of a table.
    • D. key of a table.
    • Discuss
    • 6. Which of the following is not a restriction for a table to be a relation?

    • Options
    • A. The cells of the table must contain a single value.
    • B. All of the entries in any column must be of the same kind.
    • C. The columns must be ordered.
    • D. No two rows in a table may be identical.
    • Discuss
    • 7. A functional dependency is a relationship between or among:

    • Options
    • A. tables.
    • B. rows.
    • C. relations.
    • D. attributes.
    • Discuss
    • 8. When the values in one or more attributes being used as a foreign key must exist in another set of one or more attributes in another table, we have created a(n):

    • Options
    • A. transitive dependency.
    • B. insertion anomaly.
    • C. referential integrity constraint.
    • D. normal form.
    • Discuss
    • 9. Which of the following is NOT a basic element of all versions of the E-R model?

    • Options
    • A. Entities
    • B. Attributes
    • C. Relationships
    • D. Primary keys
    • Discuss
    • 10. Which type of entity represents a logical generalization whose actual occurrence is represented by a second, associated entity?

    • Options
    • A. Supertype entity
    • B. Subtype entity
    • C. Archetype entity
    • D. Instance entity
    • Discuss


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