PL-300 Practice Test 8 — 10 Questions

Question 1

You are a data analyst at a retail company. You have a Power BI semantic model that imports sales data from an Azure SQL Database. The database uses a timestamp column to track transaction time. You need to reduce the data refresh time and ensure that only the last 30 days of data are refreshed during each scheduled refresh. You have already created the necessary parameters rangeStart and rangeEnd in Power Query. What should you do next to implement incremental refresh?

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

Accepted Answer

In Power BI Desktop, on the model view, select the table and set the incremental refresh policy.. Incremental refresh policies are defined in Power BI Desktop on the model view, not in the service or by simply filtering in Power Query. After creating the rangeStart and rangeEnd parameters, you must select the table in the Model view, open the incremental refresh policy dialog, and configure the policy to filter data based on those parameters, ensuring only the last 30 days are refreshed.

Answer

In the Power BI service, go to the dataset settings and configure the scheduled refresh.

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In Power Query Editor, apply the rangeStart and rangeEnd filters to the data and then close and apply.

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In the Power BI service, create a new refresh schedule and set the incremental refresh period.

Question 2

You need to combine two tables: Sales and Products, where Sales has a ProductID column and Products has a ProductKey column. The tables have a many-to-one relationship. Which Power Query transformation should you use?

Accepted Answer

Merge Queries.. Merge Queries (C) is correct because it performs a join between two tables based on matching columns, which is exactly what is needed to combine Sales and Products using ProductID and ProductKey. This transformation supports many-to-one relationships and allows you to expand related columns from the Products table into the Sales table, enabling further data analysis.

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Group By.

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Append Queries.

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Pivot Column.

Question 3

A company uses Row-Level Security (RLS) in Power BI. They want to ensure that when a manager views the report, they see data for their own region plus any region where a salesperson reports to them. Which RLS approach should you implement?

Accepted Answer

Use a DAX filter that references the USERPRINCIPALNAME() function. Row-Level Security (RLS) in Power BI uses DAX filters that can dynamically evaluate the current user's identity via USERPRINCIPALNAME() or USERNAME(). By creating a DAX rule that checks whether the manager's UPN matches the region manager or if the salesperson's manager UPN equals the current user, you can enforce dynamic, hierarchical data access without hardcoding roles per manager.

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Use Power BI App permissions to restrict data

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Create a static role for each manager and assign users

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Apply RLS at the visual level using bookmarks

Question 4

You are building a Power BI report for a logistics company. The data is stored in a CSV file on a SharePoint Online document library. The CSV file is updated daily with new rows. You need to ensure that the Power BI dataset reflects the latest data every morning at 7:00 AM. The data volume is small, so full refresh is acceptable. You have already published the report to the Power BI service. What should you do to automate the refresh?

Accepted Answer

In the Power BI service, configure a scheduled refresh for the dataset with the desired time.. The Power BI service supports scheduled refresh natively for datasets that connect to cloud data sources like SharePoint Online CSV files. By configuring a scheduled refresh in the dataset settings, you can set it to run daily at 7:00 AM without any additional tools or gateways. This ensures the dataset reflects the latest data from the CSV file each morning.

Answer

Use Power Automate to trigger a refresh via the Power BI REST API every morning.

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Enable incremental refresh for the dataset and set the refresh frequency to daily.

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Install an on-premises data gateway and configure a scheduled refresh.

Question 5

You are preparing data from a CSV file that contains date values in the format 'MM/dd/yyyy'. When you load the file into Power BI Desktop, the dates appear as text. What should you do to ensure the dates are recognized as date data type?

Accepted Answer

Change the column data type to Date in Power Query Editor. Changing the column data type to Date in Power Query Editor forces Power BI to interpret the text values as dates using the current locale settings. Since the CSV file contains dates in 'MM/dd/yyyy' format, Power Query can parse this pattern when the data type is explicitly set to Date, converting the text strings into the Date data type for proper time intelligence and filtering.

Answer

Use 'Replace Values' to replace '/' with '-'

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Split the column by delimiter '/'

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Promote the first row as headers

Question 6

You are designing a data model for a sales analysis report. The source data includes a Sales table with columns: OrderID, CustomerID, ProductID, OrderDate, Quantity, and UnitPrice. You also have a Customers table and a Products table. Which approach best optimizes query performance and storage?

Accepted Answer

Create a star schema with Sales as a fact table and Customers and Products as dimension tables.. A star schema optimizes query performance and storage in Power BI by separating transactional data (Sales fact table) from descriptive attributes (Customers and Products dimension tables). This reduces data duplication, improves compression, and enables efficient aggregations and filter propagation via one-to-many relationships, which is the recommended modeling approach for analytical workloads.

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Create separate fact tables for each dimension.

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Create a single flat table by joining all columns from Sales, Customers, and Products into one table.

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Create a snowflake schema by normalizing Customers into multiple related tables.

Question 7

You are preparing a Power BI dataset that includes a table 'Products' imported from an Excel workbook. The table has a column 'ProductCode' that contains values like 'A100', 'B200', etc. You need to create a new column that extracts the numeric part of the code (e.g., 100, 200) and uses it as an integer. Which Power Query transformation should you use?

Accepted Answer

Add a Custom Column with the formula Text.Select([ProductCode], {"0".."9"}) and change the type to Whole Number.. Using Text.Select with a list of digits extracts only the numeric characters from the code, regardless of the letter prefix. This creates a text column that can then be converted to an integer. Other methods are either too specific to certain prefixes or extract the wrong portion. Text.Select is the most flexible and correct approach.

Answer

Use the Replace Values transformation to replace 'A' and 'B' with an empty string, then change the type.

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Use the Extract transformation and select 'Text Before Delimiter'.

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Use the Split Column transformation by delimiter 'A' and keep the second part.

Question 8

You have a Power BI data model with a 'Date' table that contains continuous dates from January 1, 2020, to December 31, 2025. The 'Sales' table has a relationship with the 'Date' table. You need to create a measure that calculates the total sales for the last 12 months from the current context. Which DAX function should you use?

Accepted Answer

DATESINPERIOD. The DATESINPERIOD function is correct because it returns a contiguous set of dates from a specified start date (the last date in the current context) going back a given number of intervals (12 months). This allows the measure to dynamically calculate total sales for the trailing 12 months relative to any filter context, such as a specific year or month.

Answer

PREVIOUSMONTH

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DATEADD

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SAMEPERIODLASTYEAR

Question 9

You are a data analyst for a financial services company. You have a Power BI dataset that combines data from two sources: a CSV file in SharePoint Online and an on-premises SQL Server database. The CSV file contains exchange rates that are updated daily. The SQL Server database contains transaction data. You need to ensure that the dataset can be refreshed automatically in the Power BI service. The CSV file is updated at 6:00 AM daily, and the SQL Server database is updated continuously. You have already published the report. What should you do to enable automated refresh?

Accepted Answer

Install and configure an on-premises data gateway, then set up a scheduled refresh.. The on-premises SQL Server database requires an on-premises data gateway to bridge the Power BI service with the local network. Even though the CSV file is in SharePoint Online, the dataset combines both sources; the gateway is mandatory for the SQL Server component. Without it, scheduled refresh cannot access the on-premises data, and the dataset will fail to refresh automatically.

Answer

Use Power Automate to refresh the dataset after the CSV is updated.

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Enable incremental refresh for the SQL Server table to reduce refresh time.

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Configure a scheduled refresh in the dataset settings. The gateway is not required because the CSV file is in SharePoint Online.

Question 10

You are a Power BI data analyst for a manufacturing company. You have a report with a line chart showing daily production output over the past year. Users report that the line chart is cluttered and difficult to read due to daily fluctuations. You need to add analytics features to the line chart to help users identify trends and outliers. Which two features should you add? (Choose two.)

Accepted Answer

Trend line. Adding a trend line helps smooth out daily fluctuations and reveals the overall direction of production output. Anomaly detection automatically identifies and highlights unusual data points, making outliers immediately visible. Together, these features make the line chart easier to interpret. Forecast, constant line, and error bars do not directly address the need to identify trends and outliers in historical data.

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Error bars

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Forecast

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Constant line