Database Normalization
1. What kind of entity is EmployeeTerritories?
2. Without the entity EmployeeTerritories, what would the relationship between Employees and Territories be?
3. Notice the Employees entity has a relationship with itself. What is that relationship called?
4. Why does Employees have this relationship?
5. After learning about the issue, another systems analyst suggests modifying the data type on the
phone column to only be able to store one phone number. Then a shipper with two phone
numbers will have two rows in the table where only the phone numbers differ. Is this a good
solution? Why/why not?
6. If the attribute IsGift were added to Order Details to indicate if the order was a gift or not, what would the normalized form of Order Details be?
7. A programmer argues that for performance reasons, the Discontinued attribute from the
Products entity needs to be added to the Order Details entity, while still keeping the
Discontinued attribute in Products. On page 234 in your book, there are three criteria for a
good data model. Which one does this most violate?
8. In the previous scenario, what normalized form will the Order Details be in if Discontinued is added to Order Details? Why?
9. Another programmer says that it would be helpful to have a CountryCode attribute added to the Employees entity to indicate the country code of a phone number. If this change was made, what would the normalized form of the Employees entity be? Why?
10. Another suggestion is for a DaysAtJob attribute to be added to the Employees table. It will be updated daily and calculated by taking the current date and subtracting the HireDate. If this
change was made, what would the normalized form of the Employees table be? Why?
1. What kind of entity is EmployeeTerritories?
2. Without the entity EmployeeTerritories, what would the relationship between Employees and Territories be?
3. Notice the Employees entity has a relationship with itself. What is that relationship called?
4. Why does Employees have this relationship?
5. After learning about the issue, another systems analyst suggests modifying the data type on the
phone column to only be able to store one phone number. Then a shipper with two phone
numbers will have two rows in the table where only the phone numbers differ. Is this a good
solution? Why/why not?
6. If the attribute IsGift were added to Order Details to indicate if the order was a gift or not, what would the normalized form of Order Details be?
7. A programmer argues that for performance reasons, the Discontinued attribute from the
Products entity needs to be added to the Order Details entity, while still keeping the
Discontinued attribute in Products. On page 234 in your book, there are three criteria for a
good data model. Which one does this most violate?
8. In the previous scenario, what normalized form will the Order Details be in if Discontinued is added to Order Details? Why?
9. Another programmer says that it would be helpful to have a CountryCode attribute added to the Employees entity to indicate the country code of a phone number. If this change was made, what would the normalized form of the Employees entity be? Why?
10. Another suggestion is for a DaysAtJob attribute to be added to the Employees table. It will be updated daily and calculated by taking the current date and subtracting the HireDate. If this
change was made, what would the normalized form of the Employees table be? Why?
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