Power BI 778 Data Modeling in Power BI 2 — Questions and Answers
Question 1: What is a calculated column in Power BI?
- A column computed during query refresh using DAX (Correct answer)
- A column imported from a CSV file
- A column created in Power Query
- A column from a live database view
Correct answer: A column computed during query refresh using DAX
A calculated column uses a DAX expression evaluated row-by-row and stored in the model during data refresh.
Question 2: What is the purpose of a measure in Power BI?
- To store a static value in a table
- To calculate aggregated values dynamically based on filter context (Correct answer)
- To define table relationships
- To set row-level security rules
Correct answer: To calculate aggregated values dynamically based on filter context
Measures are DAX calculations that evaluate dynamically based on the filters and context applied in a report.
Question 3: In Power BI, which view allows you to see the raw data stored in each table?
- Report view
- Model view
- Data view (Correct answer)
- Query editor
Correct answer: Data view
Data view displays the actual rows and columns of data stored in each table of your Power BI model.
Question 4: What happens when you mark a table as a 'Date Table' in Power BI?
- It hides the table from the report canvas
- It enables built-in time intelligence functions to work correctly (Correct answer)
- It converts all columns to date format
- It automatically creates a calendar hierarchy
Correct answer: It enables built-in time intelligence functions to work correctly
Marking a table as a Date Table ensures Power BI's time intelligence DAX functions use that table's date column correctly.
Question 5: Which relationship cardinality is most common in a star schema Power BI model?
- Many-to-many
- One-to-one
- One-to-many (Correct answer)
- Many-to-one
Correct answer: One-to-many
One-to-many is the most common cardinality, where one dimension row relates to many fact table rows.
Question 6: What is the VertiPaq engine in Power BI?
- A query language for DirectQuery
- An in-memory columnar storage engine used for Import mode (Correct answer)
- A visualization rendering engine
- A cloud gateway service
Correct answer: An in-memory columnar storage engine used for Import mode
VertiPaq is Power BI's in-memory columnar compression engine that stores and queries imported data efficiently.
Power BI 778 Data Modeling in Power BI 2
What is a calculated column in Power BI?