Database Management System MCQs with Answers
Practice important Database Management System MCQs with answers and explanations.
Chapter: 10
Q161:
What is an example of a ternary relationship?
A. Student-Course
B. Employee-Project
C. Student-Class-Faculty
D. Department-Employee
Correct Answer:
C
Chapter: 10
Q162:
What does the "crow's foot notation" indicate in ER diagrams?
A. One-to-many cardinality
B. Many-to-one cardinality
C. Many-to-many cardinality
D. One-to-one cardinality
Correct Answer:
A
Chapter: 10
Q163:
________ relationship involves an entity linked with itself.
A. unary
B. binary
C. ternary
D. n-ary
Correct Answer:
A
Chapter: 10
Q164:
The "_____ notation" uses single and double arrows to show cardinality.
A. arrow-head
B. crow's foot
C. alphabetical
D. dot-based
Correct Answer:
A
Chapter: 10
Q165:
In a "one-to-many" relationship, the "many" indicates that ________.
A. each entity is associated with many entities
B. each entity is associated with only one entity
C. all entities are related equally
D. some entities are optional
Correct Answer:
A
Chapter: 10
Q166:
The "_______ dependency" means an entity's existence relies on another entity.
A. existence
B. referential
C. identifier
D. foreign key
Correct Answer:
A
Chapter: 10
Q167:
In ER diagrams, "1" represents a ________ cardinality.
A. one
B. many
C. optional
D. maximum
Correct Answer:
A
Chapter: 11
Q168:
What is inheritance in object-oriented programming?
A. The transfer of characteristics from one class to another
B. Writing code in different programming languages
C. Storing data in a database
D. Executing code in a specific order
Correct Answer:
A
Chapter: 11
Q169:
In the context of database systems, what does inheritance mean?
A. The transfer of properties from one entity to derived entities
B. Storing multiple types of data in a database
C. Managing access control in a database
D. Performing operations on database tables
Correct Answer:
B
Chapter: 11
Q170:
What is a supertype in a database system?
A. A major entity that is divided into subtypes
B. A specific subtype with additional properties
C. A minor entity that inherits properties from another entity
D. A type of data that does not have any attributes
Correct Answer:
A
Chapter: 11
Q171:
Which of the following is an example of a supertype/subtype relationship?
A. EMPLOYEE being divided into SALARIED and HOURLY employees
B. TRUCK being classified into different models
C. VEHICLE being categorized by color
D. PRODUCT being listed by different categories
Correct Answer:
A
Chapter: 11
Q172:
What does a total completeness constraint ensure?
A. All instances of a supertype must be represented in at least one subtype
B. No instances of a supertype need to be represented in any subtype
C. Partial representation of the supertype instances is acceptable
D. No subtypes are required for the supertype
Correct Answer:
A
Chapter: 11
Q173:
What is the disjointness constraint in database systems?
A. It restricts a supertype entity instance to only one subtype entity instance at a time
B. Allows a supertype entity instance to be associated with multiple subtype instances
C. Permits multiple instances of subtypes for a single supertype instance
D. Requires that all subtype instances are included in the supertype
Correct Answer:
A
Chapter: 11
Q174:
The overlap rule permits:
A. A supertype instance to exist in multiple subtype instances at once
B. A supertype instance to exist in only one subtype instance
C. Disjointness between a supertype and its subtypes
D. Partial completeness in subtype relationships
Correct Answer:
A
Chapter: 11
Q175:
What does the subtype discriminator help determine?
A. The specific subtype to which a supertype instance belongs
B. Whether a supertype instance is valid for database storage
C. How attributes are inherited from subtypes
D. Which attributes are common to all subtypes
Correct Answer:
A
Chapter: 11
Q176:
In the example of vehicles, what is the partial completeness constraint?
A. Only a few types of vehicles are stored in the vehicle entity, ignoring others
B. All vehicle types are stored, including those not explicitly mentioned
C. A complete representation of all vehicle types in the system
D. All vehicle data must be stored in separate subtypes
Correct Answer:
B
Chapter: 11
Q177:
Fill in the blank: The process of creating different types of sub entities from a supertype entity is supported by the __________ of the designer about the organization.
A. knowledge
B. relationships
C. data
D. storage
Correct Answer:
B
Chapter: 11
Q178:
The complete disjoint constraint means:
A. A supertype instance can be associated with only one subtype at a time
B. Multiple subtype instances can be associated with a single supertype instance
C. Partial representation of subtypes is acceptable
D. All subtype instances must be present for every supertype instance
Correct Answer:
A
Chapter: 11
Q179:
Which rule specifies that a supertype entity instance can be present in multiple subtypes?
A. Overlap rule
B. Disjointness rule
C. Partial disjoint rule
D. Complete disjoint rule
Correct Answer:
A
Chapter: 11
Q180:
Fill in the blank: In an overlapping constraint, a part that is manufactured and purchased can be represented in the __________ entity subtypes.
A. both
B. none
C. one
D. neither
Correct Answer:
A