Data Base

What is an entity in a data model?

• B. A type of attribute

• A. A type of relationship

• D. A database table

• C. A person, place, event, or object relevant to a system

How are entities represented in Entity-Relationship diagrams?

• D. By lines

• A. By circles

• B. By triangles

• C. By rectangles

What is a strong entity in a data model?

• D. An entity that is derived by using an algorithm

• C. An entity that represents a relationship

• B. An entity that exists independently of other entity types

• A. An entity that depends on other entity types

What is a weak entity in a data model?

• D. An entity that is derived by using an algorithm

• A. An entity that depends on other entity types

• B. An entity that exists independently of other entity types

• C. An entity that represents a relationship

What is a composite attribute in a data model?

• A. An attribute that cannot be broken down into simpler components

• B. An attribute that can be broken down into smaller components

• D. An attribute that is derived by using an algorithm

• C. An attribute that can have only one value

What is a single-valued attribute in a data model?

• D. An attribute that is derived by using an algorithm

• C. An attribute that can have only one value

• B. An attribute that can be broken down into smaller components

• A. An attribute that cannot be broken down into simpler components

What is a derived attribute in a data model?

• C. An attribute that can have only one value

• A. An attribute that cannot be broken down into simpler components

• D. An attribute that is derived by using an algorithm

• B. An attribute that can be broken down into smaller components

What is the purpose of a relationship in an Entity-Relationship diagram?

• A. To represent entities as rectangles

• B. To represent attributes as circles

• C. To link various components of the diagram

• D. To represent entities as triangles

What do diamonds represent in an Entity-Relationship diagram?

• D. Cardinality

• C. Attributes

• B. Relationships

• A. Entities

What does cardinality represent in a relationship?

• B. The minimum number of entities involved in the relationship

• A. The maximum number of entities involved in the relationship

• C. The type of entities involved in the relationship

• D. The strength of the relationship