Microsoft Power BI Power BI Data Modeling 2

Question 1

In Power BI, what is a 'calculated column' and when is it evaluated?

Accepted Answer

A DAX column added to a table, evaluated at data refresh/load time

Answer

A column created in Power Query, evaluated during refresh

Answer

A measure stored in a column, evaluated at query time

Answer

A column from a SQL view, evaluated at runtime

Question 2

What is a 'snowflake schema' in Power BI?

Accepted Answer

A star schema where dimension tables are further normalized into sub-tables

Answer

A schema optimized for cold climates

Answer

A schema with no fact tables

Answer

A schema with only date dimensions

Question 3

When should you use a 'measure' instead of a 'calculated column' in Power BI?

Accepted Answer

When the calculation aggregates data dynamically based on filter context

Answer

When you need to store the result in the table

Answer

When you need a row-by-row calculation stored at refresh

Answer

When you want to use the result in a slicer

Question 4

What happens to model performance if you have too many calculated columns in a large Power BI dataset?

Accepted Answer

Dataset file size increases and refresh times slow down

Answer

Performance improves due to pre-computation

Answer

Measures become invalid

Answer

Relationships break automatically

Question 5

What is the purpose of a 'date table' in a Power BI data model?

Accepted Answer

To enable time intelligence DAX functions to work correctly

Answer

To store future forecast dates

Answer

To replace the calendar in Power Query

Answer

To display dates in report visuals only

Question 6

How do you mark a table as a 'Date Table' in Power BI Desktop?

Accepted Answer

In Model View, select Mark as Date Table from the table's context menu

Answer

Right-click in Report View and select Date Table

Answer

Add a calculated column named 'IsDateTable'

Answer

Enable it in Power Query's date settings