DMC Data Modeling Fundamentals 1 — Questions and Answers
Question 1: Which of the following best defines a data model?
- A diagram showing network topology
- An abstract representation of data structures and their relationships (Correct answer)
- A physical server configuration plan
- A software deployment pipeline
Correct answer: An abstract representation of data structures and their relationships
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?
- Physical, Logical, Virtual
- External, Conceptual, Internal (Correct answer)
- Operational, Analytical, Strategic
- Raw, Processed, Stored
Correct answer: External, Conceptual, Internal
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?
- A database index
- A stored procedure
- A person, place, object, event, or concept about which data is stored (Correct answer)
- A foreign key constraint
Correct answer: A person, place, object, event, or concept about which data is stored
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?
- The data type of an attribute
- The number of instances of one entity related to instances of another (Correct answer)
- The primary key selection strategy
- The indexing method used in storage
Correct answer: The number of instances of one entity related to instances of another
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?
- Relationship
- Attribute (Correct answer)
- Cardinality
- Schema
Correct answer: Attribute
An attribute is a property or characteristic that describes an entity, such as a customer's name or birth date.
Question 6: What is the purpose of a data dictionary in data modeling?
- To store compressed database backups
- To translate SQL queries automatically
- To document the definitions, formats, and usage of data elements (Correct answer)
- To map network traffic routes
Correct answer: To document the definitions, formats, and usage of data elements
A data dictionary provides authoritative documentation of data element definitions, formats, relationships, and business rules.
DMC Data Modeling Fundamentals 1
Which of the following best defines a data model?