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- 1.Which of the following are reasons we create conceptual models?
- A.
It facilitates discussion. A picture is worth a thousand words.
- B.
It forms important ideal system documentation.
- C.
It takes into account government regulations and laws
- D.
It forms a sound basis for physical database design
- E.
All of the above.
- 2.A/an _________ is a piece of information that in some way describes an entity. It is a property of the entity and it quantifies, qualifies, classifies or specifies the entity.
- A.
ERD
- B.
Process
- C.
Attribute
- D.
Table
- 3.In a physical data model, an attribute is represented as a/an
- A.
Column
- B.
Row
- C.
Instance
- D.
Foreign Key
- 4.Unique Identifiers....
- A.
Distinguish one entity from another
- B.
Distinguish one instance of an entity from all other instances of that entity
- C.
Distinguish all entities in a database
- D.
Distinguishes nothing
- 5.Which of the following statements about attributes are true? (Choose Two)
- A.
They describe, qualify, quantify, classify, or specify an entity.
- B.
They are often adjectives.
- C.
They have a data type such as a number or character string.
- D.
They must be single valued unless they belong to more than one entity.
- 6.Some of the following could be attributes of an ENTITY called PERSON. Select the incorrect attributes for PERSON. (Choose Two)
- A.
Age
- B.
Freddy Wilson
- C.
Name
- D.
Priya Hansenna
- 7.All of the following would be instances of the entity PERSON except which?
- A.
David Jones
- B.
Male
- C.
Angelina Rosalie
- D.
Grace Abinajam
- 8.What are the three properties that every relationship should have?
- A.
Transferability, degree, name
- B.
Name, optionality, degree
- C.
A UID bar, a diamond, an arc
- D.
Name, optionality, arcs
- 9.Entity Relationship model is independent of the hardware or software used for implementation. True or False?
- A.
True
- B.
False
- 10.Relationships always exist between
- A.
3 or more entities
- B.
2 entities (or one entity twice)
- C.
2 attributes
- D.
3 or more attributes
- 11.In a business that sells computers, choose the best relationship name from CUSTOMER to ITEM (computer, in this case).
- A.
Each CUSTOMER must be the buyer of one or more ITEMS.
- B.
Each CUSTOMER must be the seller of one or more ITEMS.
- C.
Each CUSTOMER may be the maker of one or more ITEMS.
- D.
Each CUSTOMER may be the producer of one or more ITEMS.
- 12.Entity names are always plural. True or False?
- A.
True
- B.
False
- 13.Which symbol is used to indicate that a particular attribute is optional?
- A.
*
- B.
O
- C.
#
- D.
&
- 14.When reading a relationship between 2 entities, the relationship is only read from left to right. True or False?
- A.
True
- B.
False
- 15.Which of the following is true about supertypes and subtypes?
- A.
Instances that belong to two subtypes of the same supertype may be modeled as a one-to-one relationship between the two subtypes
- B.
Subtypes inherit the relationships and attributes of the supertype
- C.
Subtypes may have no more than 2 levels of nesting
- D.
Supertype and subtype entities must be mutually exclusive
- 16.Which of the following are valid formats for an attribute? (Choose Two)
- A.
Character string
- B.
Decimal
- C.
Number
- D.
HEX
- 17.Business rules are important to data modelers because:
- A.
They capture all of the needs, processes and required functionality of the business.
- B.
They are easily implemented in the ERD diagram.
- C.
The data modeler must focus on structural rules, because they are easily represented diagrammatically and eliminate other rules that involve extra procedures or programming.
- D.
Both A and C are true.
- 18.Which of the following is an example of a structural business rule?
- A.
All employees must belong to at least one department.
- B.
Buildings to be purchased by the business must be current with earthquake building code.
- C.
All overdue payments will have an added 10 % late fee.
- D.
All products will have a selling price no less than 30 % greater than wholesale.
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