The answer is to remove columns that are not used in reports and to replace text-based relationship columns with integer keys. The first action directly reduces the data model’s memory footprint by eliminating unnecessary data from the VertiPaq engine, while the second leverages integer compression—VertiPaq compresses integers far more efficiently than text, which speeds up join performance and shrinks storage. On the PL-300 exam, this topic appears in the “Optimize Model Performance” objective, often as a multiple-select question where one distractor suggests keeping all columns “just in case.” A common trap is assuming that hiding a column is equivalent to removing it; hidden columns still consume memory. For a quick memory tip, think “drop the dead weight and key the text”—meaning drop unused columns and convert text joins to integer surrogate keys for a leaner, faster model.
PL-300 Model the data Practice Question
This PL-300 practice question tests your understanding of model 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 are best practices for optimizing Power BI data models?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "best"
Why it matters: Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Replace text-based relationship columns with integer keys.
Option A is correct because replacing text-based relationship columns with integer keys (surrogate keys) reduces storage size and improves join performance. Power BI's VertiPaq engine compresses integer columns far more efficiently than text columns, leading to faster query execution and smaller memory footprint.
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.
✓
Replace text-based relationship columns with integer keys.
Why this is correct
Integer keys improve join performance.
Clue confirmation
The clue word "best" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
Use calculated columns instead of measures where possible.
Why it's wrong here
Calculated columns increase model size and are evaluated at refresh.
✗
Hide columns that are not used in reports.
Why it's wrong here
Hiding does not remove data from the model.
✓
Remove columns that are not used in reports.
Why this is correct
Reduces model size and refresh time.
Clue confirmation
The clue word "best" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
Use many-to-many relationships instead of bridge tables.
Why it's wrong here
Many-to-many can introduce ambiguity and performance issues.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse 'hiding' columns (which only affects report visibility) with 'removing' columns (which actually reduces model size and improves performance), leading them to select Option C instead of D.
Detailed technical explanation
How to think about this question
Under the hood, Power BI's VertiPaq engine uses columnar compression with techniques like value encoding and run-length encoding; integer keys allow for optimal dictionary compression and faster hash joins. In real-world scenarios, a text column like 'ProductName' with thousands of unique values can be replaced by a numeric 'ProductKey', reducing storage by up to 90% and speeding up relationship traversal. Additionally, measures are evaluated in the filter context and can leverage aggregations without materializing intermediate results, unlike calculated columns which are stored row-by-row.
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 media company stores terabytes of video archives that are accessed once a year for audit purposes. Moving these objects to a cold storage tier (Azure Archive, S3 Glacier, or Google Nearline) costs a fraction of hot storage. Questions like this test whether you understand storage tiers, access frequency tradeoffs, and retrieval latency requirements.
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.
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: Replace text-based relationship columns with integer keys. — Option A is correct because replacing text-based relationship columns with integer keys (surrogate keys) reduces storage size and improves join performance. Power BI's VertiPaq engine compresses integer columns far more efficiently than text columns, leading to faster query execution and smaller memory footprint.
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.
Are there clue words in this question I should notice?
Yes — watch for: "best". Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
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 should you take when designing a data model that includes a fact table with a large number of rows and multiple dimension tables? (Select exactly 2.)
medium
✓ A.Use integer-based foreign keys in the fact table to link to dimension tables
B.Create calculated columns in the fact table for additional attributes
C.Enable the Auto Date/Time feature for date columns
✓ D.Hide the fact table from the report view
E.Set default summarization to 'Sum' for all numeric columns in the fact table
Why A: Options A and C are correct. Option A: Using integer foreign keys reduces storage and improves join performance. Option C: Hiding the fact table from report view prevents users from accidentally querying it directly, promoting use of measures. Option B is wrong because creating calculated columns in the fact table can increase model size and degrade performance. Option D is wrong because default summarization is not recommended for fact tables; measures should be used instead. Option E is wrong because disabling auto date/time is a general best practice but not specific to large fact tables.
Last reviewed: Jun 24, 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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