DMC Data Modeling Fundamentals

Question 1

Which of the following best defines a data model?

Accepted Answer

An abstract representation of data structures and their relationships

Answer

A data model is an abstract representation that defines data structures, relationships, and constraints within a system.

Question 2

What are the three levels of data abstraction in the ANSI/SPARC architecture?

Accepted Answer

External, Conceptual, Internal

Answer

The ANSI/SPARC architecture defines three levels: External (user views), Conceptual (logical whole), and Internal (physical storage).

Question 3

In data modeling, what is an entity?

Accepted Answer

A person, place, object, event, or concept about which data is stored

Answer

An entity is a real-world object or concept — such as a customer, product, or order — about which data is collected.

Question 4

What does cardinality describe in a data model?

Accepted Answer

The number of instances of one entity related to instances of another

Answer

Cardinality defines how many instances of one entity can be associated with instances of another entity in a relationship.

Question 5

Which concept represents a property or characteristic of an entity in a data model?

Accepted Answer

Attribute

Answer

An attribute is a property or characteristic that describes an entity, such as a customer's name or birth date.

DMC - Data Modeling Certification Practice Test