The answer is filtering rows at the source to reduce data volume and disabling load for intermediate queries used only as reference steps. Filtering at the source, such as using SQL WHERE clauses or Power Query’s native query folding, minimizes the amount of data imported into the data model, directly cutting refresh time and memory overhead. Disabling load for intermediate queries prevents Power BI from materializing tables that serve only as transformation steps, so the engine skips loading unnecessary data into the model. On the PL-300 exam, this tests your understanding of Power Query’s query dependencies and the difference between reference queries and loaded tables; a common trap is assuming all queries must be loaded to the model. To improve data refresh performance in Power BI, always push filtering as far upstream as possible and treat intermediate reference queries as disposable steps. Memory tip: “Filter first, disable the rest” — reduce volume at the source, then turn off load for helper queries.
PL-300 Prepare the data Practice Question
This PL-300 practice question tests your understanding of prepare 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.
Which TWO actions can improve data refresh performance in Power BI?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Disable load for intermediate queries used only for reference.
Option C is correct because disabling load for intermediate queries used only as reference steps prevents Power BI from materializing those tables in the data model. This reduces memory consumption and refresh time, as the engine skips loading data that isn't needed for reports or further transformations.
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.
✗
Merge all queries into a single query.
Why it's wrong here
Merging queries can increase complexity and refresh time.
✗
Add calculated columns in Power Query instead of DAX.
Why it's wrong here
Calculated columns increase model size and refresh time.
✓
Disable load for intermediate queries used only for reference.
Why this is correct
Prevents unnecessary data loading.
Related concept
Read the scenario before looking for a memorised answer.
✓
Filter rows at the source to reduce data volume.
Why this is correct
Fewer rows means faster refresh.
Related concept
Read the scenario before looking for a memorised answer.
✗
Keep all columns from the source data to avoid re-importing.
Why it's wrong here
Unnecessary columns increase data volume.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates may confuse 'disable load' with 'disable refresh' or think that merging queries (Option A) is always beneficial, when in fact it can reduce parallelism and hurt performance.
Detailed technical explanation
How to think about this question
Under the hood, Power Query's 'Enable Load' setting controls whether a query's output is loaded into the Power BI data model. Disabling load for intermediate queries (e.g., date tables used only for merging) means the engine still executes the transformations but discards the result, saving memory and I/O. In real-world scenarios, a complex ETL pipeline with multiple reference queries can see refresh time reduced by 30-50% by disabling load on all but the final output queries.
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.
TExam Day Tips
→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 exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Prepare the data — This question tests Prepare the data — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Disable load for intermediate queries used only for reference. — Option C is correct because disabling load for intermediate queries used only as reference steps prevents Power BI from materializing those tables in the data model. This reduces memory consumption and refresh time, as the engine skips loading data that isn't needed for reports or further transformations.
What should I do if I get this PL-300 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
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. Which TWO actions can help reduce the size of a Power BI dataset when preparing data?
medium
A.Include all historical data
✓ B.Aggregate transaction data to daily level
C.Add calculated columns
✓ D.Remove columns that are not used in reports
E.Use DirectQuery mode
Why B: Aggregating transaction data to a daily level reduces the number of rows in the dataset, which directly decreases the storage footprint and improves refresh performance. Power BI compresses data more efficiently when cardinality is lower, and fewer rows mean smaller column dictionaries and reduced page compression overhead.
Variation 2. Which TWO actions should you take to reduce the size of a Power BI dataset? (Choose two.)
medium
✓ A.Filter out rows that are not needed.
✓ B.Remove unnecessary columns during import.
C.Disable query folding to improve performance.
D.Add calculated columns to precompute values.
E.Use DirectQuery instead of Import.
Why A: Option A is correct because filtering out unnecessary rows at the source reduces the number of rows loaded into the Power BI dataset, directly decreasing the data volume and storage size. This is a fundamental data reduction technique that minimizes memory consumption and improves refresh performance.
Variation 3. Which THREE actions in Power Query Editor can improve the performance of data refresh? (Select three.)
hard
A.Sort data in ascending order to improve compression.
B.Merge queries before filtering.
✓ C.Remove columns that are not used in the report.
✓ D.Disable the 'Enable load' option for intermediate tables that are not needed in the model.
✓ E.Filter rows as early as possible in the query.
Why C: Option C is correct because removing unused columns reduces the amount of data loaded into the Power Query engine and the data model, directly decreasing memory usage and refresh time. Power Query processes all columns in a query step, so eliminating unnecessary columns early minimizes the data footprint for subsequent transformations and the final load.
Last reviewed: Jun 11, 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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