INF652 - Quiz Study Guides
Which symbol is used to show that a particular attribute is mandatory? o & # *
*
14. If an intersection entity is formed that contains no attributes of its own, its uniqueness may be modeled by
Barring the relationships to the original entities
1. Entity names are always singular. True or False?
True
6. Relationship Cardinality is important. True or False?
True
Databases are used in most countries and by most governments. Life, as we know it, would change drastically if we no longer had access to databases. True or False?
True
Documenting Business Requirements helps developers control the scope of the system and prevents users from claiming that the new system does not meet their business requirements. True or False?
True
Data modeling is performed for the following reasons: (Choose Two) It helps discussions and reviews. We do not need data models; we can just start coding right away. We draw an ERD solely to please the users; once completed, the ERD is never referred to again as it serves no purpose in the real world. The ERD becomes a blueprint for designing the actual system.
It helps discussions and reviews. The ERD becomes a blueprint for designing the actual system.
All of the following would be instances of the entity ANIMAL SPECIES, except which one?
Leaf
3. What are the three properties that every relationship should have?
Name, optionality, cardinality
6. What relationship is described by the statements: "Each CUSTOMER may place one or more ORDERs, each ORDER must be placed by one and only one CUSTOMER"
One to Many
10. If the same relationship is represented twice in an Entity Relationship Model, it is said to be:
Redundant
8. If two entities have two relationships between them, these relationships can be either _____________ or _____________ .
Redundant or Required
7. Which of the following pairs of entities is most likely to be modeled as a M:M relationship?
TEACHER and SUBJECT AREA
The word "Volatile" means: Limited quantity Changing constantly; unstable Large quantity Static; unlikely to change
Changing constantly; unstable
A business rule such as "We only ship goods after customers have completely paid any outstanding balances on their account" is best enforced by:
Creating additional programming code to verify no goods are shipped until the account has been settled in full
9. Which of the following are used to show a relationship on an ERD? (Choose Three) Crow's foot dashed line # symbol Solid line
Crow's foot dashed line solid line
When you resolve a M:M, you simply re-draw the relationships between the two original entities; no new entities are created. True or False?
False
12. You can only create relationships to a Supertype, not to a Subtype. True or False?
False (*)
13. All instances of a subtype may be an instance of the supertype but does not have to. True or False?
False (*)
13. An ERD is an example of a Physical Model. True or False?
False (*)
Many reasons exist for creating a conceptual model. Choose three appropriate reasons from the options below. They capture current and future needs. They capture the implementation details of the physical model. They accurately describe what a physical model will contain. They model functional and informational needs. They model the information flow of data.
They capture current and future needs. They accurately describe what a physical model will contain. They model functional and informational needs.
Which of the following statements about attributes are true? They are often adjectives. They have a data type, such as number or character string. They describe, qualify, quantify, classify, or specify an entity. They must be single valued.
They have a data type, such as number or character string. They describe, qualify, quantify, classify, or specify an entity. They must be single valued.
10. When reading a relationship between 2 entities, the relationship is read both from left to right and right to left. True or False?
True
To identify an attribute as part of a unique identifier on an ER diagram, the # symbol goes in front of it. True or False?
True
When reading a relationship between 2 entities, the relationship is read both from left to right and right to left. True or false?
True
10. All instances of a subtype must be an instance of the supertype. True or False?
True (*)
11. A subtype can have a relationship not shared by the supertype. True or False?
True (*)
23. 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 (*)
6. A new system would have a mixture of both Procedural and Structural Business Rules as part of the documentation of that new system. True or False?
True (*)
9. All instances of the supertype must be an instance of one of the subtypes. True or False?
True (*)
Which of the following statements are true about ERD's? (Choose Two) A piece of information can be shown multiple times on an ERD. All data must be represented on the ERD, including derived summaries and the result of calculations. A piece of information should only be found in one place on an ERD. You should not model derivable data.
A piece of information should only be found in one place on an ERD. You should not model derivable data.
15. When you resolve a M:M by creating an intersection entity, this new entity will always inherit:
A relationship to each entity from the original M:M
Which of the following are examples of ENTITY: Instance ? (Choose Two) MEAT PRODUCT: Lettuce ANIMAL: Dog BODY PART: Larry Ellison TRANSPORTATION METHOD: Car
ANIMAL: Dog TRANSPORTATION METHOD: Car
Which of the following is an example of a volatile attribute? Name Age Hire Date Date of Birth
Age
13. Many to many relationships between entities usually hide what?
Another entity
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. Process Attribute ERD Table
Attribute
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. Table ERD Attribute Process
Attribute
A/an _________'s value can be a number, a character string, a date, an image, a sound Table Entity ERD Attribute
Attribute
7. Which of the following are true about Cardinality? (Choose two) Cardinality specifies only singularity or plurality, but not a specific plural number. Cardinality tells "how many". Cardinality specifies whether something is required or not Cardinality specifies a counting number (like 1,2, 3, 4 etc.) in a relationship
Cardinality specifies only singularity or plurality, but not a specific plural number. Cardinality tells "how many".
Which of the following entities most likely contains valid attributes? (Choose two) Entity: Home. Attributes: Number of Bedrooms, Owner, Address, Date Built Entity: Mother. Attributes: Name, Birthdate, Occupation, Start Date. Entity: Pet. Attributes: Name, Birthdate, Owner Entity: Car. Attributes: Owner Occupation, Owner Salary, Speed
Entity: Home. Attributes: Number of Bedrooms, Owner, Address, Date Built Entity: Pet. Attributes: Name, Birthdate, Owner
Personal computers (PCs) have been in existence since 1950. True or False?
False
14. A Supertype can have only one subtype. True or False?
False (*)
15. A supertype can only have two subtypes and no more. True or False?
False (*)
8. A subtype is shown on an ERD as an entity with a one to many relationship to the supertype. True or False?
False (*)
12. What do you call the entity created when you resolve a M:M relationship?
Intersection Entity
7. Why is it important to identify and document business rules?
It allows you to create a complete data model and then check it for accuracy. (*)
2. How should you handle constraints that cannot be modeled on an ER diagram?
List them on a separate document to be handled programmatically (*)
All of the following would be instances of the entity PERSON except which? David Jones Male Angelina Rosalie Grace Abinajam
Male
Which of the following statements about ERD's is false? Ensure that information appears only once. Model all information that is derivable from other information already modeled. Capture all required information. Located information in a predictable, logical place.
Model all information that is derivable from other information already modeled
18. All of the following could be attributes of an ENTITY called PERSON, except which one?
Natacha Hansen (*)
A specialized type of software, which controls and manages the hardware in a computer system.
Operating System
8. Which of the following are true about Relationship Optionality? (Choose two) Optionality specifies only singularity or plurality, but not a specific plural number. Optionality specifies a counting number (like 1,2, 3, 4 etc.) in a relationship Optionality answers "may or must". Optionality specifies whether something is required or not
Optionality answers "may or must". Optionality specifies whether something is required or not
13. Matrix Diagrams are used to verify that all relationships have been identified for an ERD. True or False?
True
15. Matrix Diagrams are developed BEFORE the ERD. True or False?
True
5. The relationship between CUSTOMER and RECEIPT is an example of a non-transferable relationship. True or False?
True
A Conceptual Model is not concerned with how the Physical Model will be implemented. True or False?
True
A new system would have a mixture of both Procedural and Structural Business Rules as part of the documentation of that new system. True or false?
True
All instances of a subtype must be an instance of the supertype. True or False?
True
An Entity Relationship model is independent of the hardware or software used for implementation. True or False?
True
Attributes can only have one value at any point for each instance in the entity. True or False?
True
ERDish describes a relationship in words. True or False?
True
Entity names are always singular. True or False?
True
Every time you shop online, it is likely you will be accessing a database. True or False?
True
In the grid computing model, resources are pooled together for efficiency. True or False?
True
Matrix Diagrams are developed BEFORE the ERD. True or False?
True
One Relationship can be mandatory in one direction and optional in the other direction. True or False?
True
One relationship can be mandatory in one direction and optional in the other direction. True or false?
True
Relationships can be either mandatory or optional. True or False?
True
Software cannot operate without Hardware. True or False
True
The Physical Model is derived from the Conceptual Model. True or False?
True
The market for IT professionals is still increasing and will continue to do so in the future as the world gets ever more dependent on computer systems. True or False?
True
The relationship between CUSTOMER and RECEIPT is an example of a non-transferable relationship. True or False?
True
5. Business rules are important to data modelers because:
A. They capture all of the needs, processes, and required functionality of the business. (*)
In the following statements, find two good examples of ENTITY: Instance. (Choose Two) VEGETABLE: grows DAIRY PRODUCT: milk BOOK: Biography of Mahatma Gandhi TRAIN: RUNS
DAIRY PRODUCT: milk BOOK: Biography of Mahatma Gandhi
1. Non-transferable relationships can only be mandatory, not optional. True or False?
False
11. A relationship on an ERD can have attributes. True or False?
False
12. Relationship names are not shown on an ERD. True or False?
False
14. Matrix Diagrams show Optionality and Cardinality of the ERDs they document. True or False?
False
2. A non-transferable relationship means the relationship is manatory at both sides. True or False?
False
4. Every ERD must have at least one non-transferable relationship. True or False?
False
9. One to many relationships are the most uncommon type of relationships in an ERD. True or False?
False
A non-transferable relationship means the relationship is mandatory at both sides. True or false?
False
A relationship on an ERD can have attributes. True or False?
False
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
All instances of a subtype may be an instance of the supertype but does not have to. True or False
False
Data Modeling is the last step in the database development process. True or False?
False
Data models are drawn to show users the actual Data that their new system will contain; only Data listed on the Diagram can be entered into the Database. True or False?
False
Entities are usually verbs. True or False?
False
Entity Relationship modeling is dependent on the hardware or software used for implementation, so you will need to change your ERD if you decide to change Hardware Vendor. True or False?
False
Many to many relationships must be left in the the Model. It is important to have them documented as M-M. True or False?
False
Matrix Diagrams show Optionality and Cardinality of the ERDs they document. True or False?
False
One to many relationships are the most uncommon type of relationships in an ERD. True or False?
False
4. How would you model a business rule that states that on a student's birthday, he does not have to attend his classes?
You cannot model this. You need to document it (*)
Which of the following are used to show Cardinality on an ERD? (Choose two) Dashed Line Solid Line Crow's foot single toe
Crow's foot single toe
10. Consider your school library. It will have a database with transaction details of the books that are borrowed by students. Is a detail of one student borrowing one book considered Data or Information?
Data (*)
3. A non-transferable relationship is represented by which of the following symbols?
Diamond
Unique Identifiers: Distinguish one entity from another. Distinguish all entities in a database. Distinguish one instance of an entity from all other instances of that entity. Distinguish nothing.
Distinguish one instance of an entity from all other instances of that entity.
Which of the following are examples of data becoming information: A. Student age -> average age of all students in class B. Bank deposit amount -> total account balance C. Winning time for a race -> length of race D. Price of a computer -> total sales of all computers for a company E. A, B, and D (*)
E. A, B, and D
11. When reading the relationships in an ERD, you are said to be speaking: Entity-ish ERDish Gibberish Relationship-ish
ERDish
3. Why is it important to identify and document structural rules?
Ensures we know what data to store and how that data works together. (*)