Applied steps and undo in Power BI - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Applied Steps Order

In Power BI's Query Editor, you apply several transformation steps to your data. If you want to remove the third step you applied, what happens to the steps that come after it?

A All steps after the removed step are also removed.

B Only the removed step is deleted; later steps remain unchanged.

C The removed step is disabled but still affects later steps.

D The entire query is reset to the original data.

💡 Hint

Think about how each step depends on the previous one.

In Power BI, each applied step builds on the previous one. Removing a step breaks the chain, so all steps after it are removed to avoid errors.

🎯 Scenario

intermediate

Undoing Changes in Query Editor

You accidentally applied a filter step that removed important rows. Which method allows you to undo this change without closing the Query Editor?

A Right-click the table and select 'Refresh Data'.

B Close the Query Editor without saving and reopen the file.

C Click the 'X' next to the filter step in the Applied Steps pane.

D Use the Undo button in the Home ribbon to revert all changes.

💡 Hint

Look for a way to remove a specific step directly.

Clicking the 'X' next to a step removes that step and all dependent steps, effectively undoing that change.

🔧 Formula Fix

advanced

Fixing a Broken Query After Undo

After removing an applied step in Power BI Query Editor, the query shows an error. What is the most likely cause?

A Power BI requires a restart after removing any applied step.

B The data source connection was lost during the undo operation.

C Undoing a step automatically deletes the entire query.

D Later steps depend on the removed step and now reference missing data.

💡 Hint

Think about dependencies between steps.

Removing a step breaks the chain for later steps that rely on it, causing errors until fixed.

❓ visualization

advanced

Visualizing Applied Steps Impact

You want to create a dashboard visualization showing how many applied steps each query in your Power BI report has. Which visual and measure combination is best?

A Use a table visual listing queries with a measure counting applied steps per query.

B Use a pie chart showing the total number of applied steps across all queries.

C Use a line chart showing applied steps count over time for each query.

D Use a card visual showing the average applied steps for all queries.

💡 Hint

Think about showing details per query clearly.

A table visual with a count measure per query clearly shows applied steps per query, making it easy to compare.

❓ data_modeling

expert

Managing Applied Steps for Performance Optimization

You have a complex query with many applied steps causing slow refresh times. Which approach best improves performance without losing data transformation accuracy?

A Disable query folding to force all transformations locally.

B Combine multiple transformation steps into fewer steps using advanced M code.

C Remove all applied steps and load raw data, then transform in DAX measures.

D Duplicate the query and apply transformations twice for safety.

💡 Hint

Think about reducing complexity while keeping transformations accurate.

Combining steps reduces overhead and improves refresh speed while preserving transformations.