Power Query and Data Transformation Flashcards
6 cards from real Microsoft Power BI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Power Query and Data Transformation flashcards as text
What does 'Query Folding' mean in Power Query?
Answer: The ability for Power Query to push transformation steps back to the data source as native queries
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.
In Power Query M language, what does the `#date(year, month, day)` function return?
Answer: A date value with the specified year, month, and day
#date() creates a date value from the specified year, month, and day integers in Power Query's M language.
What is a 'Parameter' in Power Query and what is it used for?
Answer: A named value that can be referenced in queries to make them dynamic or configurable
A Power Query Parameter is a named, typed value that can be referenced throughout your queries, enabling dynamic filtering, file paths, or connection strings.
What does the 'Replace Values' transformation in Power Query do?
Answer: Replaces specified values in a column with a different value
Replace Values finds occurrences of a specified value in a column and replaces them with another value you define.
What is the purpose of the 'Buffer' step (Table.Buffer) in Power Query?
Answer: Forces evaluation and caches the table in memory to prevent re-evaluation in subsequent steps
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.
In Power Query, what does the 'Split Column' transformation do?
Answer: Splits a text column into multiple columns based on a delimiter or character count
Split Column divides a text column into multiple new columns based on a delimiter character or fixed character width.