The correct answer is to optimize the SQL queries and add appropriate indexes in the data warehouse. This recommendation directly addresses the root cause of slow slicer performance in DirectQuery mode, where every slicer interaction sends a query back to the source database. Without proper indexing and query tuning, the SQL Server data warehouse must scan large tables for each filter change, causing noticeable delays. On the Microsoft Power BI Data Analyst PL-300 exam, this scenario tests your understanding that DirectQuery performance is entirely dependent on the source system’s ability to respond quickly, not on Power BI’s local resources. A common trap is assuming that adding more RAM to the report server or switching to Import mode will fix the issue, but Import mode bypasses DirectQuery entirely and may be impractical for large data warehouses. Remember the memory tip: “Index the source, not the report” — because DirectQuery slicers are only as fast as the database behind them.
PL-300 Visualize and analyze the data Practice Question
This PL-300 practice question tests your understanding of visualize and analyze the data. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. 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.
You have a Power BI report that uses a DirectQuery connection to a large SQL Server data warehouse. Users report that slicers and filters are slow to respond. What should you recommend to improve performance?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Optimize the SQL queries and add appropriate indexes in the data warehouse.
Option A is correct because optimizing the source query with indexes, aggregations, and reducing data volume improves DirectQuery performance. Option B is wrong because Import mode would require moving large data and may not be feasible. Option C is wrong because increasing RAM does not affect DirectQuery performance. Option D is wrong because changing to live connection doesn't improve query performance.
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.
✓
Optimize the SQL queries and add appropriate indexes in the data warehouse.
Why this is correct
Optimizing the source query improves performance for DirectQuery.
Related concept
Read the scenario before looking for a memorised answer.
✗
Change the connection to a live connection to the data warehouse.
Why it's wrong here
Live connection also relies on the source query performance.
✗
Increase the memory allocated to the Power BI service capacity.
Why it's wrong here
Memory allocation does not improve DirectQuery performance.
✗
Switch the report to Import mode and schedule refreshes.
Why it's wrong here
Import mode may not be suitable for large data volumes and requires refreshing.
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.
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.
Visualize and analyze the data — This question tests Visualize and analyze the data — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Optimize the SQL queries and add appropriate indexes in the data warehouse. — Option A is correct because optimizing the source query with indexes, aggregations, and reducing data volume improves DirectQuery performance. Option B is wrong because Import mode would require moving large data and may not be feasible. Option C is wrong because increasing RAM does not affect DirectQuery performance. Option D is wrong because changing to live connection doesn't improve query performance.
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.
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 →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. You have a Power BI report that uses a DirectQuery connection to a SQL Server database. You need to improve the performance of a visual that shows a large number of data points. What is the best action to take?
easy
A.Increase the number of data points displayed in the visual.
✓ B.Add a slicer to limit the data range.
C.Change the storage mode to Import.
D.Disable the 'cross-filter' interaction between visuals.
Why B: Option B is correct because filtering reduces the amount of data queried from the source, improving performance. Option A is wrong because increasing the number of data points worsens performance. Option C is wrong because disabling cross-filtering does not reduce the data volume. Option D is wrong because changing to Import would require a full data load, which may not be feasible for large data.
Variation 2. 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?
hard
✓ A.Create an index on the Region column in the source database
B.Increase the cache size in Power BI Desktop
C.Switch the model to Import mode
D.Reduce the number of distinct values in Region
Why A: Option D is correct because in DirectQuery mode, queries are sent to the source; creating an index on the region column will speed up filtering. Option A is wrong because Import mode is not always feasible or desired. Option B is wrong because increasing cache size does not help DirectQuery. Option C is wrong because reducing cardinality would lose information.
Last reviewed: Jun 21, 2026
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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.
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