Section 2 Database Design

CONCEPTUAL & PHYSICAL MODELS
A customized hat is an example of the conceptual model or the physical model?
Physical Model
          
Many reasons exist for creting a conceptual model. Choose three appropriate reasons from the options below.
They model functional and informational needs.
They capture current and future data needs.
They accurately describe what a physical model will contain.
          
An Entity Relationship Diagram is an example of a Physical Model. True or False?
False
          
Which of the following are reasons we create conceptual models?
All of the above
          

ENTITIES, INSTANCES, ATTRIBUTES AND IDENTIFIERS
Which of the following entities most likely contains invalid attributes?
Entity: Car. Attributes: Owner Occupation, Owner Salary, Speed
          
All of the following would be instances of the entity PERSON except which?
Male
          
What is the purpose of a Unique Identifier?
To identify one unique instance of an entity, by using one or more attributes and/or relationships.
          
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.
Attribute
          
In a physical data model, an attribute is represented as a/an
Column
          
Unique Identifiers....
Distinguish one instance of an entity from all other instances of that entity
          
Which of the following statements about attributes are true?
They describe, qualify, quantify, classify, or specify an entity.        
They have a data type such as a number or character string.
          
Entities are usually verbs. True or False?
False
          
Some of the following could be attributes of an ENTITY called PERSON. Select the incorrect attributes for PERSON.
Freddy Wilson
Priya Hansenna
          
An entity may have which of the following?
Instances
          
The word "Volatile" means....
Changing constantly; unstable
          
In the following statements, find two examples of ENTITY: Instance.
DAIRY PRODUCT: milk
BOOK: Biography of Mahatma Gandhi
          

ENTITY RELATIONSHIP MODELING AND ERDS
A well structured ERD will show only some parts of the finished data model. You should never try to model the entire system in one diagram, no matter how small the diagram might be. True or False?
False
          
An Entity Relationship model is independent of the hardware or software used for implementation. True or False?
True
          
Which of the following statements are true about ERD's?
A piece of information should only be found one place on an ERD.
You should not model derivable data.
          
The purpose of an ERD is to document the proposed system and facilitate discussion and understanding of the requirements captured by the developer. True or False?
True