PL-300 Visualize and analyze the data Practice Test 14 — 15 Questions

Question 1

You are troubleshooting a Power BI DirectQuery model that connects to a SQL Server database. A slicer on 'Region' is slow to respond. The region column has 50 distinct values. What is the best optimization?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Create an index on the Region column in the source database. The correct option is A: create an index on the Region column in the source database. In a DirectQuery model, slicer interactions are translated into SQL queries sent to SQL Server, so filtering on Region benefits directly from a supporting index that lets the database seek matching rows instead of scanning the table, which is the most targeted fix for the slow slicer. Option B does not apply because Power BI Desktop caching does not govern DirectQuery query performance against the source. Option C would improve speed but changes the model's data freshness and architecture rather than optimizing the existing DirectQuery scenario. Option D is not a valid optimization because the 50 distinct values are legitimate business data and reducing them would alter the data model's correctness.

Answer

Increase the cache size in Power BI Desktop

Answer

Switch the model to Import mode

Answer

Reduce the number of distinct values in Region

Question 2

Which TWO actions can improve the performance of a Power BI report that uses DirectQuery? (Select two.)

Accepted Answer

Set up aggregations in the data source. Option A is correct because with DirectQuery, every visual interaction translates into queries sent to the underlying source, so defining user-defined aggregations (or aggregation tables) in the data source lets Power BI satisfy many queries from pre-aggregated summary tables instead of scanning detail rows, dramatically reducing query cost and latency. Option D is correct because each visual on a DirectQuery report page typically issues its own query (or queries) to the source, so reducing the number of visuals lowers the number of concurrent queries and the volume of data returned, improving render time and easing source load. Option B is not appropriate because calculated columns are computed and stored in the model at refresh time and, in DirectQuery, they are either unsupported for certain expressions or force row-by-row evaluation that cannot be pushed down, so they do not improve query performance. Option C is wrong because adding slicers increases the number of queries and filter combinations sent to the source, which adds latency rather than reducing it. Option E is wrong because the Power BI service cache applies to imported/refreshed datasets and cached tiles, not to DirectQuery queries that must hit the source live, so increasing cache size does not speed up DirectQuery reports.

Answer

Use calculated columns instead of measures

Answer

Add more slicers to allow users to filter data

Answer

Increase the cache size in the Power BI service

Question 3

Which THREE factors should you consider when designing a Power BI data model for a star schema? (Select three.)

Accepted Answer

Fact tables should contain numeric measures and foreign keys. Option B is correct because in a star schema the fact table stores the quantitative, numeric measures (such as Sales Amount or Quantity) along with foreign keys that reference the dimension tables, forming the core of the model. Option D is correct because dimension tables hold the descriptive, textual attributes (such as Product Name, Category, or Customer City) used for slicing and filtering the measures. Option E is correct because star schema relationships are one-to-many, with the dimension on the "one" side and the fact table on the "many" side, filtered in a single direction from dimension to fact. Option A is incorrect because many-to-many relationships between dimensions are not a star schema design factor; they add ambiguity and are typically avoided or resolved via bridge tables. Option C is incorrect because dimension tables in a star schema are intentionally denormalized (flattened) to reduce the number of joins and improve query performance, not normalized to reduce redundancy.

Answer

Use many-to-many relationships between dimensions

Answer

Dimension tables should be normalized to reduce redundancy

Question 4

Which TWO Power BI visuals can be used to display hierarchical data? (Select two.)

Accepted Answer

Decomposition tree. The Decomposition tree (C) is correct because it is specifically designed to explore hierarchical data by letting users drill down through dimensions in any order, expanding nodes to reveal contributing sub-levels. The Matrix (D) is correct because it natively supports hierarchical row and column groupings, enabling expand/collapse drill-down through levels such as Year > Quarter > Month. The Scatter plot (A) is incorrect because it plots numeric values on X and Y axes to show correlations, with no hierarchical structure. The Card (B) is incorrect because it only displays a single aggregate value with no drill-down capability. The Pie chart (E) is incorrect because it shows proportional parts of a whole in a flat, single-level format without hierarchy.

Answer

Scatter plot

Answer

Card

Answer

Pie chart

Question 5

You need to design a report that allows users to drill from a yearly sales summary to quarterly details, then to monthly details, while maintaining the ability to go back. Which visual interaction should you enable?

Accepted Answer

Drill-down. Drill-down (option C) is correct because it lets users navigate a single visual's hierarchy from a yearly summary to quarterly and then monthly levels while preserving the ability to go back up the hierarchy. This matches the requirement of moving through levels of the same data rather than jumping to a separate page or filtering via saved states. Bookmarks (A) capture and restore view states but do not provide hierarchical level navigation. Tooltips (B) show supplementary detail on hover and do not change the visual's level. Drillthrough (D) navigates to a separate detail page filtered by a selected value, not down a hierarchy within the same visual.

Answer

Bookmarks

Answer

Tooltips

Answer

Drillthrough

Question 6

You have a report page that shows sales by region. You want users to be able to select a region and see the corresponding sales details on the same page without navigating away. Which feature should you use?

Accepted Answer

Slicer. A slicer is correct because it lets users interactively filter the report page by selecting a region, and the sales details visuals on that same page update in place without any navigation. This matches the requirement of staying on the same page while changing the displayed data. Drillthrough would not fit because it navigates users to a separate drillthrough page filtered to the selected item. A matrix with expand/collapse changes the level of detail within a single visual rather than filtering the whole page by region selection. A card visual only displays a single aggregated value and provides no selection mechanism.

Answer

Drillthrough

Answer

Matrix with expand/collapse

Answer

Card visual

Question 7

You need to create a visualization that shows the contribution of each product category to total sales over time. Which chart type is most appropriate?

Accepted Answer

Stacked area chart. A stacked area chart is correct because it plots each product category as a cumulative band over a continuous time axis, so the total height shows overall sales while each band's thickness shows that category's contribution to the total at every point in time. This directly satisfies the requirement to show both contribution by category and the trend over time. A clustered bar chart compares discrete category values side by side but does not naturally show their combined contribution to a running total over time. A scatter plot shows relationships between two numeric variables, not compositional contribution over time. A pie chart shows parts of a whole for a single point in time and cannot represent change over time.

Answer

Clustered bar chart

Answer

Scatter plot

Answer

Pie chart

Question 8

You have a report that contains a map visual showing sales by city. Several cities are missing from the map because the location data is ambiguous. What should you do to resolve this?

Accepted Answer

Create a calculated column that combines city and country to provide unambiguous location.. The correct option is B: create a calculated column that combines city and country to provide unambiguous location. When a map visual can't place a city because multiple places share the same name, supplying a more specific, hierarchical location string (for example, concatenating City and Country) gives the geocoding engine enough context to resolve each point uniquely. Option A is unnecessary and less precise here because adding raw latitude/longitude is a heavier modeling change than disambiguating the existing location field, and it doesn't address the root cause of ambiguous city names. Option C does not fix the data ambiguity—it merely abandons the map visualization. Option D is irrelevant, since bubble size affects rendering of plotted points, not the geocoding of missing locations.

Answer

Add latitude and longitude fields to the model.

Answer

Replace the map visual with a table.

Answer

Adjust the bubble size to make missing points visible.

Question 9

You want to allow users to filter a report by a specific date range (e.g., last 30 days) without requiring manual selection. Which approach should you take?

Accepted Answer

Add a relative date slicer to the report page.. The correct option is B: add a relative date slicer to the report page. A relative date slicer is a built-in Power BI slicer type that lets users pick dynamic ranges such as 'last 30 days', 'last 3 months', or 'this year', and it automatically recalculates based on the current date without any manual selection. Option A (bookmarks) only switches between pre-defined static views and cannot dynamically follow the current date. Option C (a calculated column flagging the last 30 days) hard-codes a fixed window at refresh time and doesn't give users an interactive range control. Option D (a filter on the date field in the Filters pane) requires users to manually specify explicit start and end dates, which is exactly the manual selection the scenario wants to avoid.

Answer

Use bookmarks to switch between fixed date ranges.

Answer

Create a calculated column that flags rows within the last 30 days.

Answer

Apply a filter on the date field in the Filters pane.

Question 10

You have a report that uses a custom visual from AppSource. The visual is not rendering correctly after a Power BI Desktop update. What is the best course of action?

Accepted Answer

Check for an updated version of the custom visual from the developer.. The correct option is C: check for an updated version of the custom visual from the developer. Custom visuals from AppSource are third-party components that can break when Power BI Desktop updates change the underlying rendering APIs, so the developer typically publishes a compatible update that resolves the rendering issue. Option A is not a real Power BI feature for custom visuals, and compatibility mode applies to semantic model/version settings, not to fixing a broken visual. Option B would discard the intended custom functionality rather than fix it, and option D merely re-adds the same outdated version, so the problem would persist.

Answer

Enable compatibility mode for the visual.

Answer

Replace the custom visual with a built-in visual.

Answer

Remove the visual and add it again from the marketplace.

Question 11

Which TWO actions improve the accessibility of a Power BI report for users with visual impairments?

Accepted Answer

Use a high-contrast color theme.. Option A is correct because applying a high-contrast color theme in Power BI (via View > Themes or a custom JSON theme) increases the luminance difference between foreground text/visuals and background, which helps users with low vision or color-vision deficiencies distinguish content. Option B is correct because adding alt text to every visual in the Visualizations pane's Format > General > Alt Text field lets screen readers such as Narrator, JAWS, or NVDA announce a meaningful description of each chart, making the report navigable for blind users. Option C is wrong because small font sizes reduce legibility rather than improve it, working against accessibility best practices. Option D is wrong because high color saturation alone does not guarantee sufficient contrast and can actually worsen readability for users with color-vision deficiencies. Option E is wrong because complex drillthrough interactions add navigation complexity and are not an accessibility improvement; simpler, predictable navigation is preferred.

Answer

Use small font sizes to fit more content.

Answer

Use high color saturation for all elements.

Answer

Include complex drillthrough interactions.

Question 12

Which THREE considerations are important when designing a dashboard for executive stakeholders?

Accepted Answer

Focus on key performance indicators (KPIs) that align with business goals.. Option A is correct because executive dashboards must center on KPIs tied directly to strategic business objectives, so leadership can immediately gauge organizational performance against goals rather than sifting through operational noise. Option B is correct because consistent colors and fonts reduce cognitive load and reinforce a credible, professional presentation, which matters when executives make rapid decisions from visual cues. Option C is correct because executives need high-level summaries first, with drill-down capability available on demand, balancing at-a-glance insight with the ability to investigate anomalies. Option D does not belong because excessive interactive slicers add complexity and clutter, slowing comprehension rather than aiding executive decision-making. Option E does not belong because detailed tables of all underlying data overwhelm a strategic audience and belong in operational or analyst-level reports, not executive dashboards.

Answer

Include as many interactive slicers as possible for flexibility.

Answer

Use detailed tables to show all underlying data.

Question 13

Which TWO actions can you take to improve the performance of a Power BI report that uses a large dataset?

Accepted Answer

Use aggregations to pre-summarize data at higher levels.. Option B is correct because aggregations let you pre-summarize large fact tables at higher grain levels (for example, daily or monthly totals) and cache those smaller tables in memory, so most report queries hit the compact aggregation table instead of scanning billions of detail rows, dramatically reducing query time. Option D is correct because every visual on a page issues its own DAX query against the dataset, so reducing the number of visuals lowers the total number of queries and the volume of data retrieved per page render, which directly improves report responsiveness. Option A is not appropriate because adding more columns to slicers increases the cardinality of filter combinations and generates larger, more complex filter context, which typically slows queries rather than speeding them up. Option C is wrong because deeply nested calculated measures are evaluated at query time and consume CPU and memory, degrading rather than improving performance. Option E is incorrect because DirectQuery pushes queries to the source database on every interaction and generally performs worse than Import mode for large datasets, not better.

Answer

Use multiple columns in slicers for more granular filtering.

Answer

Create complex calculated measures that use many nested functions.

Answer

Switch from Import mode to DirectQuery mode.

Question 14

You have a Power BI report that uses a measure to calculate year-over-year growth. Users report that the measure returns blank for certain months. The measure is: YoY Growth = DIVIDE(SUM(Sales[Amount]) - CALCULATE(SUM(Sales[Amount]), SAMEPERIODLASTYEAR('Date'[Date])), CALCULATE(SUM(Sales[Amount]), SAMEPERIODLASTYEAR('Date'[Date]))). What is the most likely cause of the blank values?

Accepted Answer

The Date table is missing dates for the previous year, causing SAMEPERIODLASTYEAR to return no data.. The correct answer is C: the Date table is missing dates for the previous year, causing SAMEPERIODLASTYEAR to return no data. SAMEPERIODLASTYEAR requires a contiguous, complete date range in a marked Date table to shift the current period back exactly one year; if prior-year dates are absent, the CALCULATE denominator returns BLANK, and DIVIDE yields BLANK for those months. Option A is not the cause because an unmarked date table would typically break time intelligence entirely rather than only certain months, and marking it is a prerequisite, not the root cause here. Option B is incorrect because DIVIDE returns BLANK only when the denominator is zero or BLANK, which is a symptom of the missing prior-year data, not the underlying cause. Option D is wrong because TOTALYTD computes a year-to-date aggregate, not a prior-year comparison, so it would not fix the YoY calculation.

Answer

The Date table is not marked as a date table.

Answer

The measure uses DIVIDE which returns blank when denominator is zero.

Answer

The measure should use TOTALYTD instead of SAMEPERIODLASTYEAR.

Question 15

You need to create a Power BI report that allows users to select a single measure from a list to display on a card visual. Which feature should you use?

Accepted Answer

Field parameters. Field parameters are the correct choice because they let report authors define a dynamic list of fields or measures that users can switch between via a slicer, directly changing what a card visual displays. In this scenario, a field parameter containing the candidate measures bound to the card's value field enables single-measure selection at runtime. Bookmarks (A) capture and replay saved filter/visibility states rather than swapping the measure bound to a visual. Tooltips (B) only show supplementary detail on hover and cannot replace the card's displayed measure. Drill-through (D) navigates to a filtered detail page and does not provide measure selection.

Answer

Bookmarks

Answer

Tooltips

Answer

Drill-through