Question 1mediummultiple choice
Full question →mediummultiple choiceObjective-mapped
A gaming company stores player scores in Azure Cosmos DB using the NoSQL API. Each document contains fields: PlayerID (unique to the player), GameID, Score, Timestamp. The most common query is: 'Retrieve all scores for a specific GameID, ordered by Score descending.' Which property should be chosen as the partition key to minimize Request Unit (RU) consumption?
Answer choices
Why each option matters
Good practice is not just finding the correct option. The wrong answers often show the exact trap the exam wants you to fall into.
A
Distractor review
PlayerID
Using PlayerID would distribute data across many partitions. Queries by GameID would need to fan out to all partitions that contain Players for that game, increasing RU consumption.
B
Best answer
GameID
GameID is the attribute used in the query filter. Choosing it as the partition key ensures that all scores for a given game are co-located in one partition, allowing a point query to that single partition and minimizing RU cost.
C
Distractor review
Score
Score has high cardinality and is used for ordering, not filtering. Using Score as partition key would not narrow the query to a single partition; the query would need to read all partitions and then sort.
D
Distractor review
Timestamp
Timestamp is not used in the filter. A partition key on Timestamp would cause the query to scatter to many partitions (since scores for a given game could have many timestamps), leading to high RU consumption.
Common exam trap
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.
Technical deep dive
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.
Related practice questions
Related DP-900 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
More questions from this exam
Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.
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FAQ
Questions learners often ask
What does this DP-900 question test?
Read the scenario before looking for a memorised answer.
What is the correct answer to this question?
The correct answer is: GameID — To minimize RU consumption for queries that filter by a specific value, the partition key should match the filter attribute. Using GameID as the partition key ensures that all documents for a given game are stored in the same logical partition. This allows the query to be served from a single partition (or a subset of partitions if you use a composite key with Score for ordering). However, for simple partition key choice, GameID is the best because it directly corresponds to the filter. PlayerID would cause cross-partition queries. Score and Timestamp have high cardinality but are not used as filters, leading to fan-out queries.
What should I do if I get this DP-900 question wrong?
Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.
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