DMC Data Modeling Fundamentals 3

Question 1

What is a recursive (or self-referencing) relationship in data modeling?

Accepted Answer

A relationship where an entity is associated with instances of itself

Answer

A recursive relationship occurs when instances of a single entity type are related to other instances of the same entity type, such as an employee managing other employees.

Question 2

What is a subtype in data modeling?

Accepted Answer

A specialized category of a supertype entity that inherits its attributes

Answer

A subtype is a specialized version of a supertype entity that inherits all supertype attributes and relationships while adding its own distinct ones.

Question 3

What principle ensures that every fact in a data model is stored in exactly one place?

Accepted Answer

Single Source of Truth (SSOT)

Answer

The Single Source of Truth principle ensures each fact is stored once and only once, eliminating redundancy and reducing inconsistency risk.

Question 4

In an ERD, what does a crow's foot notation symbol at the end of a relationship line represent?

Accepted Answer

Many (zero or more)

Answer

In crow's foot notation, the multi-pronged symbol (crow's foot) indicates the 'many' side of a one-to-many or many-to-many relationship.

Question 5

Which of the following best describes an associative entity (also known as an intersection or bridge entity)?

Accepted Answer

An entity that links two or more entities in a many-to-many relationship and may contain its own attributes

Answer

An associative entity resolves a many-to-many relationship by becoming its own entity with a composite key and potentially additional attributes.

DMC - Data Modeling Certification Practice Test

DMC - Data Modeling Certification Practice Test

DMC Data Modeling Fundamentals 3