This post is a part of the PL-300: Microsoft Power BI Data Analyst Exam Prep Hub; and this topic falls under these sections:
Prepare the data (25–30%)
   --> Transform and load the data
      --> Identify when to use reference or duplicate queries and the resulting impact

Below are 10 practice questions (with answers and explanations) for this topic of the exam.
There are also 2 practice tests for the PL-300 exam with 60 questions each (with answers) available on the hub.

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Practice Questions

Question 1

You have a query that cleans and standardizes sales data. You need to create several dimension tables from this cleaned dataset. Which option should you use?

A. Duplicate the query for each dimension
B. Reference the query for each dimension
C. Import the source data multiple times
D. Merge the query with itself

✅ Correct Answer: B

Explanation:
Referencing allows multiple tables to inherit the same cleaned logic from a single base query. This ensures consistency and reduces repeated transformation steps, which is a recommended best practice for production models.

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Question 2

What is the primary difference between a referenced query and a duplicated query?

A. Referenced queries refresh faster
B. Duplicated queries do not support transformations
C. Referenced queries depend on the original query
D. Duplicated queries cannot be loaded to the model

✅ Correct Answer: C

Explanation:
A referenced query is dependent on its source query and will reflect any changes made to it. A duplicated query is an independent copy with no dependency.

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Question 3

A change made to a base query causes multiple downstream queries to fail during refresh. What is the most likely reason?

A. The downstream queries were duplicated
B. The downstream queries were referenced
C. The model relationships were deleted
D. The data source credentials expired

✅ Correct Answer: B

Explanation:
Referenced queries rely on the base query. If a breaking change is introduced (such as removing or renaming a column), all dependent referenced queries may fail.

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Question 4

When should you duplicate a query instead of referencing it?

A. When you want transformations to stay consistent
B. When creating multiple dimension tables
C. When experimenting with major changes
D. When reducing refresh dependencies

✅ Correct Answer: C

Explanation:
Duplicating a query is ideal when testing or experimenting, because changes will not affect other queries or downstream dependencies.

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Question 5

Which impact is most commonly associated with excessive query duplication?

A. Improved refresh reliability
B. Reduced data volume
C. Increased maintenance effort
D. Better data lineage visibility

✅ Correct Answer: C

Explanation:
Duplicating queries can lead to repeated transformation logic, making the model harder to maintain and increasing the risk of inconsistent data shaping.

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Question 6

How does Power BI’s View Lineage represent referenced queries?

A. As independent branches
B. As disconnected tables
C. As upstream and downstream dependencies
D. As hidden queries

✅ Correct Answer: C

Explanation:
Referenced queries appear as downstream dependencies in View Lineage, clearly showing how data flows from base queries to derived queries.

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Question 7

You want to ensure that a change to data cleansing logic automatically applies to all derived tables. What should you do?

A. Duplicate the query
B. Reference the query
C. Disable query loading
D. Create calculated tables

✅ Correct Answer: B

Explanation:
Referencing ensures that any change to the base query propagates to all dependent queries automatically.

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Question 8

Which of the following is a common mistake when using referenced queries?

A. Using them for experimentation
B. Using them for dimension creation
C. Forgetting that changes propagate downstream
D. Using them to centralize data cleaning

✅ Correct Answer: C

Explanation:
A frequent mistake is forgetting that changes to a referenced base query can unintentionally affect multiple dependent queries.

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Question 9

Which approach generally results in a cleaner and more maintainable data model?

A. Duplicating all queries
B. Referencing a well-designed base query
C. Importing data separately for each table
D. Performing transformations in DAX

✅ Correct Answer: B

Explanation:
Using a base query with referenced downstream queries centralizes transformation logic and simplifies maintenance, which aligns with Microsoft’s recommended modeling practices.

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Question 10

Which scenario best illustrates when NOT to use a referenced query?

A. Creating a product dimension
B. Applying consistent formatting rules
C. Testing a new transformation approach
D. Creating multiple tables from a single source

✅ Correct Answer: C

Explanation:
Referenced queries should not be used when testing or experimenting with transformations, because changes may impact other dependent queries. Duplicating is safer in this case.

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PL-300 Exam Tip

Expect Microsoft to test:

• Dependency awareness
• Impact of changes
• Maintainability vs flexibility
• Correct use of Reference vs Duplicate

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