584 Databases: Exercise 2 Results

I just finished Exercise 2, and the results aren’t pretty. I scored 111 out of 145 total points. Here is the breakdown by question and my explanation of where I went wrong.

7. Which of the following is NOT a good characteristic of a data name?
A.
Relates to business characteristics
B.
Readable
C.
Repeatable
D.
Relates to a technical characteristic of the system

I chose A, but the correct answer is D.

8. A fact is an association between two or more:

A.
words
B.
terms
C.
facts
D.
nuggets

I chose A, but the correct answer is B. I wasn’t clear on the definition of “term,” so I chose word. But a term is the correct name.

9. A good data definition will have all of the characteristics of a data object EXCEPT:
A.
subtleties
B.
examples
C.
who determines the value of the data
D.
who can delete the data

I chose B, but the correct answer is D. I need to reread the section on data definitions. Who can delete the data apparently isn’t part of the definition, which makes sense.

13. The following figure shows an example of:

A.
a one-to-many relationship
B.
a strong entity and its associated weak entity
C.
a co-dependent relationship
D.
a double-walled relationship

I chose A and B, but the correct answer is only B. I see it now that this isn’t a one to many relationship.

26. Which of the following criteria should be considered when selecting an identifier?
A.
Choose an identifier that is stable
B.
Choose an identifier that will not be null
C.
Choose an identifier that doesn’t have large composite attributes
D.
Use intelligent key

I chose A, B, and D, but the correct answers are A, B, and C. I guess intelligent doesn’t really mean anything here. We should chose those without a bunch of composite parts.

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