1Z0-006 Data Modeling 3

Question 1

Which of the following is an example of a multivalued attribute in an ERD?

Accepted Answer

Employee's phone numbers (can have several)

Answer

A multivalued attribute can hold more than one value for a single entity instance, such as an employee having multiple phone numbers.

Question 2

In Third Normal Form (3NF), which type of dependency must be eliminated?

Accepted Answer

Transitive dependency of a non-key attribute on another non-key attribute

Answer

3NF requires that no non-key attribute depends on another non-key attribute (transitive dependency); all non-key attributes must depend directly on the primary key.

Question 3

What distinguishes a physical data model from a logical data model?

Accepted Answer

A physical model includes specific DBMS data types, indexes, and storage details

Answer

A physical data model extends the logical model with DBMS-specific details such as data types, indexes, tablespaces, and partitioning strategies.

Question 4

An EMPLOYEE entity has a 'Years_of_Service' attribute that is always calculated from 'Hire_Date'. What type of attribute is 'Years_of_Service'?

Accepted Answer

Derived attribute

Answer

A derived attribute is one whose value is computed from other stored attributes and is typically shown with a dashed oval in ERDs.

Question 5

Which constraint ensures that a foreign key value in a child table must match an existing primary key value in the parent table?

Accepted Answer

Referential integrity constraint

Answer

Referential integrity ensures that a foreign key either matches a primary key in the referenced table or is NULL, preventing orphaned records.

(1Z0-006) Oracle Database Foundations Associate Practice Test

(1Z0-006) Oracle Database Foundations Associate Practice Test

1Z0-006 Data Modeling 3