Preview Questions Data Modeling Concepts | Role Specific Skill

Question 1: You need to calculate the cumulative sales for each product. Which SQL function do you use?

Which action should you take?

Choose only one option

Use a window function with SUM()

Use a nested query with GROUP BY

Use a JOIN with aggregate functions

Use a CTE with a rolling sum

Question 2: When should you use a weak entity in an ER model?

Which action should you take?

Choose only one option

When the entity cannot be uniquely identified without another entity.

When the entity has a composite attribute.

When the entity is optional.

When the entity has a multivalued attribute.

Question 3: In your ER model, you have an entity Employee and an entity Department. How do you ensure each employee belongs to one department?

Which action should you take?

Choose only one option

Add a foreign key in Employee referencing Department.

Add a foreign key in Department referencing Employee.

Create an associative entity between Employee and Department.

Define a many-to-many relationship between Employee and Department.

Question 4: You need to show how objects interact in a specific scenario. Which UML diagram do you use?

Which action should you take?

Choose only one option

Use a sequence diagram

Use a class diagram

Use a state diagram

Use an activity diagram

Question 5: You find that some tables in your database are not fully normalized. How do you proceed?

Which action should you take?

Choose only one option

Apply normalization up to Third Normal Form (3NF)

Apply Second Normal Form (2NF)

Apply First Normal Form (1NF)

Use Boyce-Codd Normal Form (BCNF)

Question 6: A team member suggests adding redundant attributes to an entity. What do you do?

Which action should you take?

Choose only one option

Explain the drawbacks of redundancy

Implement the suggestion and monitor the impact

Create a separate entity for the redundant attributes

Use derived attributes instead