PL-300 Practice Test 29 — 15 Questions

Question 1

You are designing a Power BI report for a sales team. The team needs to see revenue by product category, but also want to view daily trends for a selected product. The data has over 10 million rows. What visual design approach minimizes report load time?

Accepted Answer

Create a drillthrough page with a line chart showing daily revenue, and use category page as source. Using a drillthrough page with a single visual reduces initial load. Option A is correct. Option B is wrong because a single visual with all categories may be slow. Option C is wrong because bookmarks add complexity. Option D is wrong because custom visuals may have overhead.

Answer

Use a custom visual that combines both views in one chart

Answer

Use bookmarks to switch between category view and daily trend view

Answer

Place a stacked column chart showing all categories and a line chart for trend on the same page

Question 2

You have a Power BI report that uses a composite model with both Import and DirectQuery sources. You need to ensure that a measure using SUMX performs well. What should you do?

Accepted Answer

Create a calculated column in the source system to pre-aggregate values. In composite models, iterating over DirectQuery tables can be slow. Option C is correct: move the calculation to the source (e.g., SQL view). Option A is wrong because reducing cardinality may not help. Option B is wrong because disabling relationships is not practical. Option D is wrong because changing to SUM might change logic.

Answer

Disable relationships between tables

Answer

Use CALCULATE instead of SUMX

Answer

Replace SUMX with SUM and adjust the model

Question 3

Which TWO actions can improve the performance of a Power BI report that uses DirectQuery?

Accepted Answer

Push transformations to the data source.. Options A and D are correct. Reducing columns reduces data transfer; setting bidirectional cross-filtering can cause performance issues, but increasing it is not recommended; using calculated columns in DirectQuery is slow; you should push transformations to the source. Option B is wrong because bidirectional cross-filtering can degrade performance. Option C is wrong because calculated columns are evaluated row-by-row in DirectQuery. Option E is wrong because increasing cross-filtering direction adds complexity.

Answer

Create calculated columns instead of measures.

Answer

Use bidirectional cross-filtering.

Answer

Increase cross-filter direction to both.

Question 4

You have a report page that shows sales by product category. You want to allow users to click on a category and see a detailed breakdown of products within that category on a separate page. Which Power BI feature should you implement?

Accepted Answer

Drillthrough page with category as a drillthrough field. Option B is correct because drillthrough allows passing a filter to another page. Option A is wrong because tooltips show on hover, not click. Option C is wrong because a slicer filters the same page. Option D is wrong because bookmarks navigate to a state, not filter another page.

Answer

Add a slicer for product category

Answer

Bookmark that shows the detail page

Answer

Report page tooltips

Question 5

You have a report that uses a live connection to a Power BI dataset. You want to add a table visual that shows sales by product, but you notice that you cannot add a calculated column. What is the reason?

Accepted Answer

Live connections do not support calculated columns; they must be created in the source dataset.. Option A is correct because live connections do not allow adding calculated columns; they must be created in the source dataset. Option B is wrong because table visuals are allowed. Option C is wrong because aggregations are possible. Option D is wrong because RLS is supported.

Answer

Live connections require row-level security which prevents calculated columns.

Answer

Table visuals are not supported with live connections.

Answer

You need to enable 'Allow calculations' in the dataset settings.

Question 6

Refer to the exhibit. You configure incremental refresh for a Power BI dataset with the above policy. The dataset contains 3 years of historical data. How will the rolling window affect the data?

Accepted Answer

Only the most recent 10 days will be refreshed. The rolling window of 10 days means only the last 10 days are refreshed incrementally. Historical data beyond 30 days is not refreshed unless a full refresh occurs. The mode 'merge' does not affect this.

Answer

Data older than 30 days will be merged into the history

Answer

All data older than 30 days will be removed

Answer

The entire dataset will be refreshed every 10 days

Question 7

A user wants to see the top 10 products by sales but also include a total row at the bottom of the table. How can you achieve this?

Accepted Answer

Enable the total row in the formatting pane of the table visual. Option B is correct because the 'Show items with no data' option is unrelated, and a total row can be enabled in the formatting pane for table visuals. Option A is wrong because the total row is not a built-in feature for all visuals; it is available in table/matrix visuals. Option C is wrong because the 'Top N' filter does not include a total row. Option D is wrong because a calculated column is not needed.

Answer

Apply a Top N filter to the visual and add a measure for total

Answer

Use the 'Show items with no data' option

Answer

Create a separate card visual for total sales

Question 8

You are building a report that uses a calculated column with the formula: 'Profit = Sales[Revenue] - Sales[Cost]'. Users report that the Profit column shows negative values for some rows when it should be positive due to a known data issue in the Cost column. What is the best approach to handle this without modifying the source data?

Accepted Answer

Modify the calculated column to use COALESCE or IF to treat missing or incorrect cost values.. Option C is correct because using Data Analysis Expressions (DAX) functions like IF or COALESCE allows you to handle data quality issues within the model. Option A is wrong because it uses DirectQuery, but the issue is in the model, not the query type. Option B is wrong because conditional formatting only changes visual appearance, not the underlying value. Option D is wrong because removing negative values would hide the issue without fixing it.

Answer

Create a measure that filters out rows with negative profit.

Answer

Apply conditional formatting on the Profit column to hide negative values.

Answer

Switch the table to DirectQuery mode to retrieve live data.

Question 9

You have a Power BI report that uses a DirectQuery connection to a large SQL Server data warehouse. Users report that slicers and filters are slow to respond. What should you recommend to improve performance?

Accepted Answer

Optimize the SQL queries and add appropriate indexes in the data warehouse.. Option A is correct because optimizing the source query with indexes, aggregations, and reducing data volume improves DirectQuery performance. Option B is wrong because Import mode would require moving large data and may not be feasible. Option C is wrong because increasing RAM does not affect DirectQuery performance. Option D is wrong because changing to live connection doesn't improve query performance.

Answer

Change the connection to a live connection to the data warehouse.

Answer

Increase the memory allocated to the Power BI service capacity.

Answer

Switch the report to Import mode and schedule refreshes.

Question 10

You have a Power BI report that uses Import mode. The dataset is refreshed daily. Users are complaining that the report shows data from yesterday morning even though the refresh completed successfully at 2:00 AM today. What should you check first?

Accepted Answer

Examine the incremental refresh policy's rangeStart and rangeEnd parameters. The dataset might be using incremental refresh with a filter that excludes recent data, or the source data hasn't updated. Option C is correct. Option A is wrong because refresh history shows success. Option B is wrong because gateway is not the issue. Option D is wrong because role permissions don't affect data freshness.

Answer

Check row-level security (RLS) role assignments

Answer

Check the refresh history for errors

Answer

Verify the on-premises data gateway is running

Question 11

You need to create a measure that calculates the year-over-year growth of sales. Which DAX function should you use?

Accepted Answer

SAMEPERIODLASTYEAR. Option C is correct because SAMEPERIODLASTYEAR returns the same period last year, which is used in YoY calculations. Option A is wrong because PARALLELPERIOD shifts by a full period, not necessarily the same days. Option B is wrong because DATEADD can shift by any interval. Option D is wrong because PREVIOUSYEAR returns the full previous year, not the same period.

Answer

DATEADD

Answer

PARALLELPERIOD

Answer

PREVIOUSYEAR

Question 12

Which TWO are valid ways to distribute a Power BI report to users who do not have Power BI Pro licenses?

Accepted Answer

Embed the report in a Power BI app with Premium capacity.. Options A and D are correct. A Power BI Premium capacity allows sharing with free users; a paginated report can be embedded in a Power BI app; B is wrong because sharing directly requires Pro or Premium per user; C is wrong because exporting to PDF requires the user to have access; E is wrong because publishing to web makes it public, not just for non-Pro users.

Answer

Share the report via Power BI service sharing.

Answer

Export the report as PDF and email it.

Answer

Publish to web (public).

Question 13

You are reviewing a Power BI report with the JSON configuration shown in the exhibit. The visual is supposed to display the top 5 product categories by total sales, with all remaining categories grouped into 'Other'. However, the visual shows only the top 5 categories and no 'Other' bar. What is the most likely reason?

Accepted Answer

The 'otherGroup' section lacks a 'showOther' property set to true.. Option B is correct because the 'otherGroup' is defined but the aggregation of 'Other' must be enabled in the visual formatting; missing 'showOther' flag. Option A is wrong because JSON version 2.0 is valid. Option C is wrong because sorting does not affect grouping. Option D is wrong because the format is correct JSON.

Answer

The JSON version is incorrect; must be 3.0.

Answer

The 'sortOrder' should be 'ascending' for 'Other' to appear.

Answer

The JSON is malformed; missing closing bracket.

Question 14

Your Power BI report includes a bar chart showing monthly sales. Users complain that the bars are too crowded when viewing a full year. What is the best design change to improve readability?

Accepted Answer

Add a slicer for quarter to filter the view. Sorting by sales value does not reduce crowding, changing to a line chart is better for continuous data, and removing axis labels harms readability. Slicing by quarter reduces the number of bars visible at once.

Answer

Sort the bars by sales value descending

Answer

Switch to a line chart

Answer

Remove the axis labels

Question 15

Refer to the exhibit. You run this DAX query and receive an error. What is the most likely reason?

Accepted Answer

SUMMARIZECOLUMNS requires a measure, not an aggregation expression. SUMMARIZECOLUMNS cannot use SUM directly; it requires an explicit filter context or a measure. A measure should be defined first or use CALCULATE. The syntax is correct but the expression is invalid.

Answer

The column 'Category' does not exist

Answer

SUMMARIZECOLUMNS is deprecated

Answer

EVALUATE cannot be used in DAX queries