Database - Logical Database Design
Exercise :: Logical Database Design - General Questions
| 11. |
A relation has which of the following properties? |
| A. |
Each row is not unique. | | B. |
Attributes can have the same name within a given table. | | C. |
Each relation has a unique name. | | D. |
The order of the columns is significant. |
Answer: Option C
Explanation:
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| 12. |
When mapping a ternary relationship with an associative entity into a relation which of the following is true? |
| A. |
One relation is created. | | B. |
Two relations are created. | | C. |
Three relations are created. | | D. |
Four relations are created. |
Answer: Option D
Explanation:
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| 13. |
When mapping a regular entity into a relation which of the following is true? |
| A. |
One relation is created. | | B. |
Two relations are created. | | C. |
Three relations are created. | | D. |
Four relations are created. |
Answer: Option A
Explanation:
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| 14. |
When mapping a supertype/subtype relationship which of the following is true? |
| A. |
The supertype primary key is assigned to each subtype. | | B. |
The subtype primary key is assigned to each supertype. | | C. |
There is no link between the supertype/subtype entities. | | D. |
There is no primary key/foreign key relationship between a supertype/subtype. |
Answer: Option A
Explanation:
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| 15. |
Relations are: |
| A. |
two-dimensional tables. | | B. |
three-dimensional tables. | | C. |
four-dimensional tables. | | D. |
five-dimensional tables. |
Answer: Option A
Explanation:
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