30 Questions
What does the design process of a database application involve?
All of the above
Which phase of the database design process involves interacting with users to understand the needs of the application?
Conceptual-design phase
What does a high-level data model provide to the database designer?
A conceptual framework to specify data requirements
What is the purpose of the logical-design phase in the database design process?
To map the conceptual schema onto the implementation data model
Why is it important to carry out the database design phase with care?
To avoid difficulties in making changes to the logical schema
Which attribute type can be divided into subparts?
Composite attribute
Which attribute is a composite attribute?
name
Which concept is NOT part of the E-R data model?
Redundancy
Which pitfall should be avoided in database design?
Redundancy
What is the purpose of the E-R model in database design?
To facilitate database design
What is an entity in the context of the E-R model?
A 'thing' or 'object' in the real world
Which of the following best describes an entity in a database?
A collection of entities of the same type
Which of the following is an example of an attribute for the 'Instructor' entity set?
Dept Name
Which of the following best describes a relationship set in an E-R schema?
A set of relationships between different entity sets
What is the purpose of a relationship instance in an E-R schema?
To represent an association between named entities in the real-world enterprise
How are relationship sets represented in an E-R diagram?
As diamonds linked via lines to entity sets
True or false: The domain of attribute course id might be the set of all text strings of a certain length.
True
True or false: The domain of attribute semester might be strings from the set {Fall, Winter, Spring, Summer}.
True
True or false: Simple attributes have not been divided into subparts.
True
True or false: Composite attributes are used in the E-R model.
True
True or false: Multivalued attributes in an E-R diagram map directly into attributes for the appropriate relation schemas.
False
Which of the following is true about primary keys in entity sets?
Primary keys are a set of attributes that uniquely identify entities in an entity set.
What is the purpose of keys in relationship sets?
Keys help to identify relationships uniquely and distinguish relationships from each other.
In an E-R diagram, how is a total participation of a weak entity set in its identifying relationship set represented?
With a double line
What is the purpose of removing redundant attributes from entity sets in database design?
To avoid duplication of data
Which type of relationship in the E-R model can have a primary key formed by the union of the primary keys of participating entity sets?
Many-to-many relationship
In the E-R model, if an entity set participates more than once in a relationship set, what is used to form a unique attribute name?
The role name
Which of the following best describes a weak entity set in the context of the E-R model?
An entity set that is dependent on another entity set for its existence
What is the primary key of the relation schema derived from the strong entity set 'student' in the E-R diagram?
ID
How is a weak entity set depicted in an E-R diagram?
Via a double rectangle with the discriminator underlined with a dashed line
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
