Microsoft Power BI Power BI Data Modeling 1 — Questions and Answers
Question 1: In Power BI, what type of relationship allows you to filter in both directions between two tables?
- One-to-many
- Many-to-many
- Bidirectional cross-filter (Correct answer)
- One-to-one
Correct answer: Bidirectional cross-filter
Bidirectional cross-filter relationships allow filters to propagate in both directions between related tables.
Question 2: Which cardinality type is recommended as a best practice for most relationships in Power BI data models?
- Many-to-many
- One-to-one
- One-to-many (Correct answer)
- Many-to-one
Correct answer: One-to-many
One-to-many is the recommended cardinality because it follows star schema design principles and provides the best performance.
Question 3: What is a star schema in Power BI data modeling?
- A schema with no relationships
- A central fact table surrounded by dimension tables (Correct answer)
- A schema with only calculated columns
- A schema where all tables are flat
Correct answer: A central fact table surrounded by dimension tables
A star schema consists of a central fact table connected to multiple dimension tables, resembling a star shape.
Question 4: In Power BI, what is the purpose of a 'bridge table' in a many-to-many relationship scenario?
- To store calculated measures
- To resolve many-to-many relationships by breaking them into two one-to-many relationships (Correct answer)
- To improve query performance
- To store hierarchy levels
Correct answer: To resolve many-to-many relationships by breaking them into two one-to-many relationships
A bridge table resolves many-to-many relationships by acting as an intermediary table, splitting the relationship into two one-to-many links.
Question 5: What does the 'Assume Referential Integrity' option do when enabled on a relationship in Power BI?
- Forces referential integrity checks on every refresh
- Allows Power BI to use more efficient INNER JOIN queries instead of OUTER JOINs (Correct answer)
- Creates automatic calculated columns
- Prevents duplicate rows in fact tables
Correct answer: Allows Power BI to use more efficient INNER JOIN queries instead of OUTER JOINs
Enabling 'Assume Referential Integrity' tells Power BI to use INNER JOINs instead of OUTER JOINs, improving query performance.
Question 6: Which tool within Power BI Desktop allows you to define and manage relationships between tables visually?
- Report View
- Data View
- Model View (Correct answer)
- Table View
Correct answer: Model View
Model View provides a visual canvas where you can see and manage all table relationships in your data model.
Microsoft Power BI Power BI Data Modeling 1
In Power BI, what type of relationship allows you to filter in both directions between two tables?