Unit 6: Optimizing Power BI Performance - Practice Quiz

INT374 — Data Analytics With Power Bi 50 Questions
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1 What is the primary purpose of the 'Optimize' ribbon introduced in Power BI Desktop?

A. To write complex DAX formulas automatically
B. To manage data relationships and cardinality
C. To provide tools for controlling visual refresh and analyzing performance
D. To create custom visual themes and layouts

2 Which button in the Optimize ribbon prevents visuals from updating automatically while you are making changes to the report?

A. Freeze Pane
B. Lock Visuals
C. Stop Queries
D. Pause Visuals

3 When 'Pause Visuals' is active, what must a user do to see the updated data in a specific visual?

A. There is no way to update a single visual
B. Restart Power BI Desktop
C. Click the 'Refresh' button on the specific visual overlay
D. Switch to Data view and back

4 Which tool is used to record and analyze the time taken by visual elements to load and render?

A. SQL Server Profiler
B. DAX Formatter
C. Query Editor
D. Performance Analyzer

5 In the Performance Analyzer results, what does the 'DAX query' metric represent?

A. The time waiting for other operations to complete
B. The time taken to download data from the cloud
C. The time required by the analytical engine to execute the query
D. The time it takes to render the visual on the screen

6 Which of the following is NOT a category of duration shown in Performance Analyzer?

A. Network latency
B. DAX query
C. Other
D. Visual display

7 What feature in the Optimize ribbon allows you to quickly apply pre-configured settings for 'Query reduction' or 'Interactivity'?

A. Optimization Presets
B. Performance Tuner
C. Quick Measures
D. Theme Gallery

8 If you select the 'Query reduction' setting within Optimization Presets, what change is commonly applied to slicers?

A. Slicers are converted to dropdowns
B. Slicers automatically select all values
C. Slicers become invisible
D. An 'Apply' button is added to slicers

9 In Performance Analyzer, what does the 'Copy query' function allow you to do?

A. Duplicate the visual on the canvas
B. Copy the resulting data table to Excel
C. Copy the visual formatting settings
D. Copy the SQL or DAX generated by the visual to the clipboard

10 What is the meaning of the 'Visual display' duration in Performance Analyzer?

A. Time required to render the visual elements (charts, graphs) on the screen
B. Time spent calculating DAX measures
C. Time taken to retrieve data from the source
D. Time spent waiting for other visuals to load

11 Under the 'Other' category in Performance Analyzer, what is a common cause for a high duration?

A. Applying conditional formatting
B. Waiting for other visuals to finish refreshing (queueing)
C. Rendering complex maps
D. Complex DAX calculations

12 When using the Optimize ribbon, how can you force all visuals to reload data from the cache or source?

A. Click 'Refresh Visuals'
B. Click 'Pause Visuals'
C. Close and Reopen the file
D. Click 'Optimization Presets'

13 Which storage mode generally benefits most from 'Query Reduction' settings?

A. Import Mode
B. Live Connection
C. Dual Mode
D. DirectQuery

14 What happens to cross-highlighting when 'Query reduction' presets are applied?

A. It forces a data refresh
B. It changes color
C. It is usually disabled by default
D. It becomes faster

15 To use Performance Analyzer, what must you do first after opening the pane?

A. Click 'Start recording'
B. Select a visual
C. Write a DAX measure
D. Export to Excel

16 Which external tool is most commonly paired with Performance Analyzer to fine-tune DAX queries?

A. Notepad
B. Excel
C. Power Automate
D. DAX Studio

17 What file format does Performance Analyzer export its results to?

A. .CSV
B. .XML
C. .JSON
D. .PBIX

18 In the context of the Optimize ribbon, what does 'Customizing' presets allow?

A. Changing the report background
B. Changing the color of the ribbon
C. Creating new DAX functions
D. Manually adjusting settings for slicers and filters distinct from the default presets

19 Which visual type typically consumes the most 'Visual display' time?

A. Maps or Scatter charts with thousands of data points
B. Simple Bar chart
C. Slicer
D. Card visual

20 When 'Pause Visuals' is enabled, what happens to the Filter Pane?

A. Changes are pending until the visual is unpaused or refreshed
B. It works normally
C. Changes are applied immediately
D. It disappears

21 Why might a DAX query duration be 0 ms or extremely low in Performance Analyzer?

A. The query failed
B. DAX is not used in Power BI
C. The data is being retrieved from the visual cache (already loaded)
D. The visual is broken

22 How can you clear the cache to get an accurate cold-cache reading in Performance Analyzer without restarting?

A. Use the 'Clear Cache' feature in DAX Studio or add a blank page then return
B. Toggle the visual type
C. There is a 'Clear Cache' button directly in the Optimize ribbon
D. Delete the page

23 Which of the following is a symptom of a report needing optimization?

A. The report has more than 2 pages
B. Visuals take several seconds to load after clicking a slicer
C. The report uses custom colors
D. The report uses a Star Schema

24 The 'Optimize' ribbon was introduced to help report creators working specifically with which type of data models?

A. Static CSVs
B. Small Excel files
C. Large models and DirectQuery sources
D. SharePoint lists

25 Can Performance Analyzer record actions across multiple report pages?

A. Only if the pages are duplicated
B. Yes, it continues recording until you press Stop
C. Only in Power BI Service
D. No, it stops when you switch pages

26 What is the 'Apply' button on the Filter pane used for in Optimization settings?

A. To apply formatting changes
B. To apply filter changes in bulk rather than individually
C. To apply the filter to all pages
D. To save the report

27 Which element allows you to sort Performance Analyzer results by 'Total duration' or 'Action order'?

A. The Optimize ribbon settings
B. You cannot sort the results
C. The View tab
D. The sort icons in the header of the Performance Analyzer pane

28 If a visual displays a 'Loading...' spinner for a long time, which Performance Analyzer metric will likely be highest?

A. DAX query
B. Copy duration
C. Evaluation
D. Visual display

29 Using the 'Optimize' ribbon, where can you find the option to 'Add an Apply button to all slicers'?

A. Performance Analyzer
B. Pause Visuals
C. Optimization Presets -> Query Reduction
D. Refresh Visuals

30 Does the 'Pause Visuals' feature stop the data refresh from the underlying data source (e.g., scheduled refresh)?

A. Yes, but only for SQL sources
B. No, it only stops the visual rendering on the canvas
C. No, it deletes the data source
D. Yes, it stops all data movement

31 What is the benefit of disabling 'Cross-highlighting' in optimization presets?

A. It increases the file size
B. It makes the report more colorful
C. It reduces the number of queries generated when selecting elements in a chart
D. It enables drill-through

32 If 'Other' duration is high in Performance Analyzer, what is a potential fix?

A. Change the chart color
B. Reduce the number of visuals on the page
C. Rewrite the DAX measure
D. Increase font size

33 Which visual interaction setting sends the most queries by default?

A. Full Interactivity (default)
B. Fixed Layout
C. Static Mode
D. Query Reduction

34 What indicates that a visual is currently 'Paused'?

A. An overlay message says 'Visual is paused'
B. The visual shows old data with no warning
C. The visual disappears
D. The visual turns black

35 In the Performance Analyzer, can you see the performance of Custom Visuals?

A. Yes, they appear like any other visual
B. No, custom visuals are ignored
C. Yes, but only the DAX portion
D. No, only native visuals

36 What is the result of clicking 'Refresh visuals' in the Optimize ribbon while 'Pause visuals' is still active?

A. It automatically turns off 'Pause visuals' permanently
B. It produces an error
C. The visuals refresh once, then return to the paused state
D. Nothing happens

37 Which of the following is NOT a column in the exported JSON file from Performance Analyzer?

A. duration
B. visualType
C. action
D. programmerName

38 When optimizing a report, what is the recommended approach for row-level security (RLS)?

A. Test performance with RLS roles applied as it can impact query generation
B. RLS has no impact on performance
C. Disable RLS for all users
D. Use RLS only on text columns

39 If you want to permanently keep 'Apply' buttons on slicers for a specific report, where should you configure this if not using the Optimize ribbon presets?

A. View > Themes
B. Home > Transform Data
C. Modeling > Manage Roles
D. File > Options and settings > Options > Current File > Query reduction

40 How does 'Pause Visuals' help when creating a new DAX measure?

A. It highlights syntax errors
B. It writes the code for you
C. It increases the DAX formula bar size
D. It prevents visuals from throwing errors or recalculating while the measure is incomplete or being typed

41 Which of these is a best practice for optimizing data models before using the Optimize ribbon tools?

A. Import all columns from the source
B. Keep all relationships bi-directional
C. Use Calculated Columns instead of Measures
D. Use a Star Schema and remove unnecessary columns

42 In Performance Analyzer, if 'Copy query' is greyed out (unavailable) for a specific item, what does it likely mean?

A. The visual generated no DAX query (e.g., a text box or image)
B. The visual is paused
C. The visual is too slow
D. You are not an admin

43 What is the primary trade-off when using Optimization Presets set to 'Query Reduction'?

A. There is no trade-off
B. Faster refresh at the cost of security
C. Better graphics at the cost of data accuracy
D. Better performance at the cost of one-click interactivity

44 Can Performance Analyzer identify bottlenecks caused by Power Query transformations?

A. No, it only analyzes the front-end report performance (DAX and Rendering)
B. Yes, directly
C. Yes, under the 'ETL' category
D. Yes, but only for Excel sources

45 If a slicer allows 'Multi-select' with an Apply button enabled, when is the query sent?

A. After every single checkbox click
B. Only when the user clicks 'Apply' after making all selections
C. Randomly
D. When the user hovers over the slicer

46 The Optimize ribbon is available in which version of Power BI?

A. Power BI Mobile only
B. Excel Add-in only
C. Power BI Report Builder only
D. Power BI Desktop

47 What does a high 'Evaluation' time in a DAX query (seen in detailed breakdown) usually suggest?

A. Slow rendering
B. Slow internet
C. Missing fonts
D. Inefficient DAX code or high cardinality scans

48 How does limiting the number of visuals on a page help optimization?

A. It automatically fixes DAX errors
B. It saves ink when printing
C. It allows more colors to be used
D. It reduces the number of concurrent queries the engine must process

49 Can you use Performance Analyzer to compare the speed of two different visuals displaying the same data?

A. Only if they are custom visuals
B. No, it only records the whole page
C. Yes, by recording them side-by-side or sequentially
D. No, it only works on bar charts

50 If you wish to return to the default behavior after using 'Optimization Presets', which option should you choose?

A. Pause Visuals
B. Disable Optimization
C. Full Interactivity
D. Query Reduction