Quick Answer
The answer is that the job is being restarted and reprocessing data, which is the most likely cause of duplicate output after a failure. When a Stream Analytics job recovers from a failure, it replays input events from the last saved checkpoint, and if the output sink—like Azure SQL Database—is not idempotent, the same windowed aggregation results are written again, creating duplicates. On the DP-203 exam, this tests your understanding of Stream Analytics’ exactly-once processing guarantees versus at-least-once delivery behavior during recovery, a common trap where candidates overlook that checkpoint-based replay can reintroduce data. A key memory tip is to think of “recovery replay” as the culprit: any job restart, even from a brief outage, will reprocess the window, so always design your output to handle duplicates via upserts or deduplication logic.
This DP-203 practice question tests your understanding of develop data processing. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. 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 are using Azure Stream Analytics to process real-time temperature data from IoT devices. The output must be written to Azure SQL Database. The job has been running successfully for weeks, but recently you notice that the output data has duplicate rows. The input events are unique. The job uses a windowed aggregation (TumblingWindow). What is the most likely cause of duplicates?
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.
The job is not handling late-arriving events.
Why wrong: Late events cause out-of-order but not duplicates.
The job is being restarted and reprocessing data.
Restart can cause reprocessing and duplicate output without idempotent writes.
The input event hub is receiving duplicate events.
Why wrong: Input is stated as unique.
The tumbling window size is too small.
Why wrong: Window size does not cause duplicates.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
The job is being restarted and reprocessing data.
Option D is correct because when a Stream Analytics job recovers from a failure, it reprocesses input from the last checkpoint, which can cause duplicate output if the output is not idempotent. Option A is wrong because window size affects aggregation but not duplicates. Option B is wrong because late events can cause out-of-order results but not duplicates if handled correctly. Option C is wrong because the input is unique, so duplicates are not from input.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
The job is not handling late-arriving events.
Why it's wrong here
Late events cause out-of-order but not duplicates.
The job is being restarted and reprocessing data.
Why this is correct
Restart can cause reprocessing and duplicate output without idempotent writes.
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 input event hub is receiving duplicate events.
Why it's wrong here
Input is stated as unique.
The tumbling window size is too small.
Why it's wrong here
Window size does not cause duplicates.
Common exam traps
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
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.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
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
Identify which DP-203 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.
Develop data processing — study guide chapter
Learn the concepts, then practise the questions
Develop data processing practice questions
Targeted practice on this topic area only
All DP-203 questions
846 questions across all exam domains
Microsoft Azure Data Engineer Associate DP-203 study guide
Full concept coverage aligned to exam objectives
DP-203 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Practise DP-203 questions linked to Secure, monitor, and optimize data storage and data processing.
Practise DP-203 questions linked to Design and develop data processing.
Practise DP-203 questions linked to Design and implement data security.
Practise DP-203 questions linked to Monitor and optimize data storage and processing.
Practise DP-203 questions linked to Design and implement data storage.
Practise DP-203 questions linked to Develop data processing.
Practise DP-203 questions linked to DP-203 fundamentals.
Practise DP-203 questions linked to DP-203 scenario.
Practise DP-203 questions linked to DP-203 troubleshooting.
Practice this exam
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Develop data processing — This question tests Develop data processing — Read the scenario before looking for a memorised answer..
The correct answer is: The job is being restarted and reprocessing data. — Option D is correct because when a Stream Analytics job recovers from a failure, it reprocesses input from the last checkpoint, which can cause duplicate output if the output is not idempotent. Option A is wrong because window size affects aggregation but not duplicates. Option B is wrong because late events can cause out-of-order results but not duplicates if handled correctly. Option C is wrong because the input is unique, so duplicates are not from input.
Identify which DP-203 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.
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
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 →
Last reviewed: Jun 21, 2026
This DP-203 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 DP-203 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.