Microsoft Power BI Power Query and Data Transformation 2

Question 1

What does 'Query Folding' mean in Power Query?

Accepted Answer

The ability for Power Query to push transformation steps back to the data source as native queries

Answer

Query Folding means Power Query translates transformation steps into native source queries (like SQL), so the source executes them instead of Power Query processing everything in memory.

Question 2

In Power Query M language, what does the `#date(year, month, day)` function return?

Accepted Answer

A date value with the specified year, month, and day

Answer

#date() creates a date value from the specified year, month, and day integers in Power Query's M language.

Question 3

What is a 'Parameter' in Power Query and what is it used for?

Accepted Answer

A named value that can be referenced in queries to make them dynamic or configurable

Answer

A Power Query Parameter is a named, typed value that can be referenced throughout your queries, enabling dynamic filtering, file paths, or connection strings.

Question 4

What does the 'Replace Values' transformation in Power Query do?

Accepted Answer

Replaces specified values in a column with a different value

Answer

Replace Values finds occurrences of a specified value in a column and replaces them with another value you define.

Question 5

What is the purpose of the 'Buffer' step (Table.Buffer) in Power Query?

Accepted Answer

Forces evaluation and caches the table in memory to prevent re-evaluation in subsequent steps

Answer

Table.Buffer caches the table contents in memory so that subsequent references to it don't re-evaluate the full transformation pipeline, improving performance in certain scenarios.

Microsoft Power BI Practice Test

Microsoft Power BI Practice Test

Microsoft Power BI Power Query and Data Transformation 2