The answer is that the RLS rule fails because USERPRINCIPALNAME() returns the full user principal name (e.g., user@west.contoso.com), while the Region column likely contains only the region name (e.g., "West"), so the comparison never matches. This mismatch is the most common reason an RLS rule does not filter rows in Power BI—the filter expression compares two different data types or granularities, causing every row to evaluate as false. On the PL-300 exam, this scenario tests your understanding of dynamic row-level security using DAX functions like USERPRINCIPALNAME() and how to properly extract a substring with functions such as MID or SEARCH. A frequent trap is assuming the UPN matches a short region code directly, so always verify the column’s content against the function’s output. Memory tip: UPN is the full email address, not just the region—trim it before you compare it.
PL-300 Model the data Practice Question
This PL-300 practice question tests your understanding of model the data. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
Exhibit
Refer to the exhibit.
```json
{
"name": "RLS Sales",
"rules": [
{
"table": "Sales",
"filterExpression": "[Region] = USERPRINCIPALNAME()"
}
]
}
```
You apply the above RLS rule to a semantic model. The rule is intended to restrict sales data by the user's region, which is stored in the user's email domain (e.g., user@west.contoso.com). However, the rule does not filter any rows. What is the most likely issue?
Refer to the exhibit. You apply the above RLS rule to a semantic model. The rule is intended to restrict sales data by the user's region, which is stored in the user's email domain (e.g., user@west.contoso.com). However, the rule does not filter any rows. What is the most likely issue?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Refer to the exhibit.
```json
{
"name": "RLS Sales",
"rules": [
{
"table": "Sales",
"filterExpression": "[Region] = USERPRINCIPALNAME()"
}
]
}
```
You apply the above RLS rule to a semantic model. The rule is intended to restrict sales data by the user's region, which is stored in the user's email domain (e.g., user@west.contoso.com). However, the rule does not filter any rows. What is the most likely issue?
A
The Sales table does not have a Region column.
Why wrong: The filter expression uses Region.
B
USERPRINCIPALNAME() is not available in the current Power BI version.
Why wrong: It is available.
C
The filter expression compares the full UPN to the Region column, which likely contains only the region name.
USERPRINCIPALNAME() returns 'user@west.contoso.com', not just 'West'.
D
The RLS rule is not applied to the semantic model.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The filter expression compares the full UPN to the Region column, which likely contains only the region name.
Option B is correct because USERPRINCIPALNAME() returns the full UPN, which includes the domain. The filter expression compares the entire UPN to the Region column, which likely contains only the region part (e.g., 'West'). Option A is wrong because the rule is applied. Option C is wrong because the table exists. Option D is wrong because USERPRINCIPALNAME() is valid.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
The Sales table does not have a Region column.
Why it's wrong here
The filter expression uses Region.
✗
USERPRINCIPALNAME() is not available in the current Power BI version.
Why it's wrong here
It is available.
✓
The filter expression compares the full UPN to the Region column, which likely contains only the region name.
Why this is correct
USERPRINCIPALNAME() returns 'user@west.contoso.com', not just 'West'.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
The RLS rule is not applied to the semantic model.
Why it's wrong here
The exhibit shows it is applied.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Trap categories for this question
Command / output trap
The exhibit shows it is applied.
Detailed technical explanation
How to think about this question
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
Use explanations to understand the rule behind the answer.
TExam Day Tips
→Underline the problem statement mentally.
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A cloud solutions architect for a retail company is evaluating services for a new workload. The correct answer here reflects best practice for the specific scenario described — not a general cloud recommendation. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Cloud exam questions reward reading the constraint carefully: the same technology can be right or wrong depending on the use case.
What to study next
Got this wrong? Here's your next step.
Identify which PL-300 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Model the data — This question tests Model the data — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The filter expression compares the full UPN to the Region column, which likely contains only the region name. — Option B is correct because USERPRINCIPALNAME() returns the full UPN, which includes the domain. The filter expression compares the entire UPN to the Region column, which likely contains only the region part (e.g., 'West'). Option A is wrong because the rule is applied. Option C is wrong because the table exists. Option D is wrong because USERPRINCIPALNAME() is valid.
What should I do if I get this PL-300 question wrong?
Identify which PL-300 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
This PL-300 practice question is part of Courseiva's free Microsoft certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the PL-300 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.