Extended Entity Relationship DIagram

Fill in the Blanks

A

is a generic entity type that has a relationship with one or more subtypes.

Multiple Choice

Which of the following best describes the relationship between a supertype and its subtypes in an extended entity relationship diagram?

• A supertype is a general entity type that can be subdivided into specialized subtypes.

• A subtype is a general entity type that can be subdivided into specialized supertypes.

• A supertype and subtype are always identical in attributes.

• A subtype contains all attributes of all supertypes.

Multiple Choice

Which attributes are shared by all entities in a supertype according to the diagram?

• Identifier and common attributes

• Unique attributes for each subtype

• Only relationship attributes

• No attributes are shared

Multiple Choice

Which of the following is a common attribute for all subtypes of Person in an Extended Entity Relationship Diagram?

• PersonID

• EmployeeID

• CustomerID

• SupplierID

Multiple Choice

Based on the example provided, which of the following is NOT an attribute of salaried employees?

• Hourly_Rate

• Employee_number

• Annual_Salary

• Stock_Option

Multiple Choice

Which attributes are unique to the CONSULTANT entity in the database system diagram?

• Contract_Number and Billing_Rate

• Employee_Number and Address

• Hourly_Rate and Annual_Salary

• Stock_Option and Date_Hired

Fill in the Blanks

The process of defining a more general entity type from a set of more specialized entity types is called

.

Multiple Select

Which of the following are considered specialized entity types in the generalization example involving vehicles?

• CAR

• TRUCK

• MOTORCYCLE

• VEHICLE

Multiple Choice

Which of the following is a common attribute shared by all subtypes of the 'Person' supertype in an Extended Entity Relationship Diagram?

• EmployeeID

• PersonID

• LoyaltyPoints

• ProductSupplied

Multiple Select

Which rules are associated with the completeness constraint in database specialization?

• Total specialization rule

• Partial specialization rule

• Referential integrity rule

• Entity integrity rule

Multiple Choice

What is the main purpose of the completeness constraint in specifying constraints for database systems?

• To ensure every instance of a supertype is a member of at least one subtype

• To define the attributes of a supertype

• To create relationships between different entities

• To enforce data integrity in all tables

Multiple Choice

Which rule specifies that each entity instance of the supertype must be a member of some subtype in the relationship?

• Total Specialization Rule

• Partial Specialization Rule

• Disjoint Rule

• Overlap Rule

Multiple Select

Which of the following statements about disjointness constraints is correct?

• Disjointness constraints determine if an instance of a supertype can be a member of multiple subtypes simultaneously.

• Disjointness constraints only apply to partial specialization.

• Disjointness constraints are not relevant in ER diagrams.

• Disjointness constraints have two possible rules: disjoint rule and overlap rule.

Fill in the Blanks

A patient must be either an outpatient or a resident patient, but cannot be both. This is an example of the

rule.

Fill in the Blanks

The attribute of the supertype whose values determine the target subtype or subtypes is called the

discriminator.

Multiple Select

Which of the following books is referenced for learning about database system concepts in this course?

• Fundamentals of Database Systems by Elmasri & Navathe (7th Edition)

• Database System Concepts by Silberschatz, Korth & Sudarshan (6th Edition)

• Modern Database Management by Hoffer, Ramesh & Topi (12th Edition)

• Database System Design: Design, Implementation and Management by Coronel & Morris (12th Edition)

Open Ended

Reflecting on today's session about Extended Entity Relationship Diagrams, what are some real-world scenarios where you think using subtypes like Employee, Customer, and Supplier would be beneficial in designing a database?

Open Ended

Why is it important to distinguish between supertypes and subtypes in an Extended Entity Relationship Diagram (EERD)?

Open Ended

Explain the significance of subtyping in database systems and provide an example based on the slides.

Open Ended

Describe how the concept of supertype/subtype can be applied to model employees in an organization. Use the attributes listed in the example to support your answer.

Open Ended

Explain the difference between generalization and specialization in the context of database system concepts.

Open Ended

Describe a scenario in which the overlap rule would be more appropriate than the disjoint rule in an ER diagram.