Database- Logical Database Design
Database- Logical Database Design
1. The entity integrity rule states that:
- no primary key attribute may be null.
- no primary key can be composite.
- no primary key may be unique.
- no primary key may be equal to a value in a foreign key.
2. When mapping a many-to-many unary relationship into a relation which of the following is true?
- One relation is created.
- Two relations are created.
- Three relations are created.
- Four relations are created.
3. If no multivalued attributes exist and no partial dependencies exist in a relation, then the relation is in what normal form?
- First normal form
- Second normal form
- Third normal form
- Fourth normal form
4. A foreign key is which of the following?
- Any attribute
- The same thing as a primary key
- An attribute that serves as the primary key of another relation
- An attribute that serves no purpose
5. A transitive dependency is which of the following?
- A functional dependency between two or more key attributes
- A functional dependency between two or more nonkey attributes.
- A relation that is in first normal form.
- A relation that is in second normal form.
6. When mapping a multivalued attribute into a relation which of the following is true?
- One relation is created.
- Two relations are created.
- Three relations are created.
- Four relations are created.
7. If no multivalued attributes exist in a relation, then the relation is in what normal form?
- First normal form
- Second normal form
- Third normal form
- Fourth normal form
8. A primary key is which of the following?
- Any attribute
- An attribute that uniquely identifies each row
- An attribute that uniquely identifies each column
- A derived attribute
9. The relational model consists of:
- data in the form of tables.
- data redundancy.
- operations using non-SQL languages.
- unorganized data.
10. When mapping a binary many-to-many relationship into a relation which of the following is true?
- One relation is created.
- Two relations are created.
- Three relations are created.
- Four relations are created.