The answer is that the DMS full load task did not use transactional consistency. When AWS DMS performs a full load without ongoing replication, it captures a snapshot of the source database, but if the source has active transactions at the moment of capture, the snapshot may be inconsistent, leading to missing data even though no modifications occurred during the migration. This scenario tests your understanding of how DMS handles transactional boundaries during full loads on the AWS Certified Database Specialty DBS-C01 exam, a common trap where candidates assume a static source guarantees completeness. The key insight is that DMS full load does not automatically enforce a consistent read; you must explicitly enable transactional consistency to ensure all committed transactions are included. Memory tip: think of a full load as a photograph—if someone is blinking, you miss the detail unless you use a consistent snapshot.
DBS-C01 Deployment and Migration Practice Question
This DBS-C01 practice question tests your understanding of deployment and migration. Examine the command output carefully: the correct answer depends on what the output actually shows, not on general recall alone. 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.
A company is migrating a 100 GB Microsoft SQL Server database from an on-premises data center to Amazon RDS for SQL Server. The migration uses AWS DMS with full load only (no ongoing replication). The full load completes successfully, but the company's application team reports that some data in the target database is missing. The source database was not modified during the migration. The DMS task logs show no errors. What is the MOST likely cause of the missing data?
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.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The DMS task did not use transactional consistency.
DMS full load captures a snapshot of the source database. If the source database has active transactions during the snapshot, some changes may not be included. Using transactional consistency ensures a consistent snapshot. Disabling foreign keys is not recommended. Using a larger instance does not affect consistency.
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.
✗
The DMS task used the 'Change Data Capture' mode instead of full load.
Why it's wrong here
The task was full load only; CDC would capture changes.
✗
The target RDS instance was not large enough to store all data.
Why it's wrong here
Storage was sufficient as full load completed.
✓
The DMS task did not use transactional consistency.
Why this is correct
Without transactional consistency, DMS may not capture all changes in a consistent state.
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 source database had foreign key constraints that were not migrated.
Why it's wrong here
Foreign keys would be migrated if included.
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 DBS-C01 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.
Deployment and Migration — This question tests Deployment and Migration — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The DMS task did not use transactional consistency. — DMS full load captures a snapshot of the source database. If the source database has active transactions during the snapshot, some changes may not be included. Using transactional consistency ensures a consistent snapshot. Disabling foreign keys is not recommended. Using a larger instance does not affect consistency.
What should I do if I get this DBS-C01 question wrong?
Identify which DBS-C01 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.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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This DBS-C01 practice question is part of Courseiva's free Amazon Web Services 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 DBS-C01 exam.
Question Discussion
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