PL-300 Practice Test 7 — 10 Questions

Question 1

You are preparing data from a SQL Server database for a Power BI report. The database contains a table with millions of rows of sales transactions. You need to minimize the data load time and reduce the model size. What should you do?

Accepted Answer

Import only the required columns and apply row-level filters in Power Query.. Option D is correct because importing only the necessary columns and applying filters to reduce rows directly reduces the amount of data loaded into Power BI, minimizing load time and model size. Option A is wrong because DirectQuery would avoid import but not reduce load time for queries and may impact performance. Option B is wrong because Power Query folding is automatic for SQL Server but does not reduce data volume unless combined with filters. Option C is wrong because incremental refresh requires a date column and configured policy, but does not reduce initial load.

Answer

Configure incremental refresh without filtering.

Answer

Enable query folding in Power Query.

Answer

Use DirectQuery instead of Import mode.

Question 2

You are building a Power BI data model that combines Sales data from SQL Server and Marketing data from a CSV file. The Sales table has a unique 'OrderID' column, and the Marketing table has a 'CampaignID' column. You need to create a relationship between Sales and Marketing to analyze campaign effectiveness. What should you do?

Accepted Answer

Create a bridge table containing unique combinations of OrderID and CampaignID.. Option B is correct because a bridge table resolves the many-to-many relationship between Sales (OrderID) and Marketing (CampaignID). Since there is no direct key match, creating a bridge table with unique combinations of OrderID and CampaignID allows Power BI to model the relationship correctly and analyze campaign effectiveness without data duplication or ambiguity.

Answer

Use an inactive relationship between Sales and Marketing and activate it with USERELATIONSHIP in measures.

Answer

Create a separate table for each campaign and relate to Sales.

Answer

Merge the Marketing table into the Sales table using a left outer join.

Question 3

You are importing data from a folder containing multiple CSV files with identical structure. You want to automatically combine all files into one table in Power Query. Which connector should you use?

Accepted Answer

Folder connector. The Folder connector is the correct choice because it is specifically designed to connect to a folder containing multiple files, and when combined with the 'Combine Files' transformation in Power Query, it automatically merges all CSV files with identical structures into a single table. This connector handles the iterative process of reading each file and appending rows without manual scripting.

Answer

Excel Workbook connector

Answer

CSV connector

Answer

Web connector

Question 4

Which TWO transformations in Power Query are most likely to cause Query Folding to stop? (Select two.)

Accepted Answer

Pivot columns.. Option A is correct because Pivot columns in Power Query often require a transformation that cannot be translated into a native SQL query, causing Query Folding to break. When you pivot a column, the engine must restructure data from rows to columns, which typically involves operations like grouping and aggregation that many source systems (e.g., SQL Server) cannot fold back to a single SELECT statement. This forces Power Query to pull all data locally before applying the pivot, stopping folding.

Answer

Filter rows based on a date column.

Answer

Remove columns.

Answer

Rename a column.

Question 5

You are importing data from an Excel workbook that has multiple worksheets. You only need data from the 'Sales' worksheet. When you connect via Power Query, all worksheets appear in the Navigator. What should you do to load only the 'Sales' worksheet?

Accepted Answer

Select the 'Sales' worksheet in Navigator and click 'Load'. Option A is correct because selecting the worksheet and clicking Load loads it. Option B is incorrect because Transform Data opens Power Query for transformation. Option C is incorrect because that would load all. Option D is incorrect because deleting steps is unnecessary.

Answer

Load all worksheets, then delete the unwanted ones

Answer

Select all worksheets and click 'Load'

Answer

Select the 'Sales' worksheet and click 'Transform Data'

Question 6

You are loading data from an Excel workbook that has multiple sheets. Each sheet contains sales data for a different region. You need to combine all sheets into one table. What is the most efficient approach?

Accepted Answer

Use Power Query's 'From Folder' option to combine all Excel files in a folder, then select 'Combine & Transform' to use the workbook as a sample.. Option D is correct because the 'From Folder' option in Power Query is designed to combine multiple Excel files with the same structure into a single table. By pointing to a folder containing the workbook, Power Query automatically detects all sheets as separate files and uses the 'Combine & Transform' feature to union them, which is more efficient than manually appending each sheet individually.

Answer

Use 'Append Queries' for each sheet individually.

Answer

Use 'Merge Queries' to join all sheets into one.

Answer

Load each sheet as a separate table in the model and create a calculated table to union them.

Question 7

Which TWO data sources can be used with DirectQuery mode in Power BI? (Choose two.)

Accepted Answer

SQL Server. SQL Server is correct because it is a relational database that supports DirectQuery mode in Power BI, allowing queries to be sent directly to the source without importing data. This enables real-time access to large datasets while leveraging SQL Server's query processing capabilities.

Answer

Excel workbook

Answer

CSV file

Answer

SharePoint list

Question 8

You are loading data from a folder containing multiple Excel files with identical structure. Some files have inconsistent column names due to manual edits. You need to ensure that all data is loaded correctly without errors. What should you do in Power Query?

Accepted Answer

Use the 'Combine Files' feature with a sample file, then in the transformation step, promote headers and rename columns using a mapping table.. Option A is correct because the 'Combine Files' feature in Power Query uses a sample file to infer the schema, and then you can apply transformations like promoting headers and renaming columns using a mapping table to handle inconsistent column names across files. This ensures all data loads without errors by standardizing the column names before combining.

Answer

Use 'Merge Queries' to join the files based on row position.

Answer

Change the data source to a SharePoint folder and use 'Load to Data Model' directly.

Answer

In Power Query, use 'Enter Data' to manually create the schema.

Question 9

You are combining data from multiple Excel files stored in SharePoint Online. Each file has the same structure but different data. You need to create a solution that automatically includes new files added to the SharePoint folder without manual intervention. What should you use?

Accepted Answer

Use 'Get Data from SharePoint Online Folder' and then 'Combine files' transform.. Option B is correct because the 'Combine files' transform in Power Query from a SharePoint folder automatically detects and combines all files in the folder, and when refreshed, it includes any new files. Option A is wrong because Get Data from SharePoint list does not combine files. Option C is wrong because Power Automate would require additional setup and is not native Power Query. Option D is wrong because merging queries requires manual steps each time.

Answer

Use Power Automate to copy new files to a blob storage, then import from there.

Answer

Use 'Merge queries' to append each new file manually.

Answer

Use 'Get Data from SharePoint Online List' and load each file separately.

Question 10

You are debugging a Power Query that imports a CSV file. The exhibit shows the M code. The CSV file contains a header row and data. Some rows have a comma inside a quoted field (e.g., "Smith, John"). What issue will arise from this code?

Accepted Answer

The QuoteStyle.None option will cause commas inside quotes to be treated as delimiters.. Option B is correct because the M code uses `QuoteStyle.None`, which tells Power Query to treat commas inside quoted fields as column delimiters rather than as part of the field value. This causes rows with values like "Smith, John" to be split incorrectly, resulting in extra columns and misaligned data. The correct option for CSV files with quoted fields is `QuoteStyle.Csv`, which respects the standard CSV quoting rules.

Answer

The encoding 1252 is incorrect for the file.

Answer

The number of columns specified (5) is too many.

Answer

The Promoted Headers step will fail because the first row contains quotes.