The answer is AWS DMS with ongoing replication because it enables a database migration to RDS with minimal downtime by continuously capturing and applying changes from the source PostgreSQL database to the target RDS instance after the initial full load. This approach leverages Change Data Capture (CDC) to keep both databases synchronized, allowing you to cut over to RDS in seconds rather than hours. On the AWS Certified Data Engineer Associate DEA-C01 exam, this scenario tests your understanding of migration strategies for large datasets under tight windows—a common trap is choosing a full dump and restore, which forces extended downtime for a 2 TB database. Remember that DMS with ongoing replication is the only option that decouples the bulk transfer from the final switchover. Memory tip: think “DMS = Data Minimizes Stoppage” to recall that ongoing replication keeps the source live until you’re ready to flip the switch.
DEA-C01 Data Store Management Practice Question
This DEA-C01 practice question tests your understanding of data store management. 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.
A data engineer is migrating an on-premises PostgreSQL database to Amazon RDS for PostgreSQL. The database is 2 TB in size and has a tight migration window. Which migration approach minimizes downtime?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Use AWS DMS with ongoing replication to capture changes during migration.
Option D is correct because AWS DMS with ongoing replication allows minimal downtime. Option A is full dump and restore, causing downtime. Option B is slow. Option C requires manual setup.
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.
✗
Use AWS Database Migration Service (DMS) with full load only.
Why it's wrong here
Full load only still causes downtime for changes during migration.
✗
Use pg_dump to export the database and pg_restore to import into RDS.
Why it's wrong here
Full dump/restore requires application downtime.
✗
Create a read replica in RDS and promote it when ready.
Why it's wrong here
RDS for PostgreSQL read replica requires source to be RDS.
✓
Use AWS DMS with ongoing replication to capture changes during migration.
Why this is correct
Ongoing replication syncs changes until cutover, minimizing downtime.
Related concept
Read the scenario before looking for a memorised answer.
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 DEA-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.
Data Store Management — This question tests Data Store Management — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Use AWS DMS with ongoing replication to capture changes during migration. — Option D is correct because AWS DMS with ongoing replication allows minimal downtime. Option A is full dump and restore, causing downtime. Option B is slow. Option C requires manual setup.
What should I do if I get this DEA-C01 question wrong?
Identify which DEA-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.
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. A data engineer needs to migrate an on-premises PostgreSQL database to Amazon RDS for PostgreSQL. The database is 2 TB and has a continuous stream of write operations. The migration should minimize downtime. Which AWS service should be used?
medium
A.AWS DataSync
✓ B.AWS Database Migration Service (DMS)
C.AWS Snowball Edge
D.AWS Glue
Why B: Option B is correct because AWS DMS supports ongoing replication from on-premises PostgreSQL to RDS, allowing minimal downtime. Option A (S3) is for bulk data transfer. Option C (Snowball) is for offline data transfer, not for ongoing replication. Option D (Glue) is for ETL, not for database migration with replication.
Variation 2. A data engineer is migrating an on-premises Oracle database to Amazon RDS for Oracle. The database is 5 TB in size and has a 1 Gbps network connection. The migration must be completed within 48 hours. Which service should be used?
hard
A.AWS DataSync.
B.Amazon S3 Transfer Acceleration.
C.AWS Snowball Edge.
✓ D.AWS Database Migration Service (DMS).
Why D: AWS DMS is the correct choice because it is designed for migrating databases to AWS with minimal downtime, and it can handle a 5 TB Oracle database over a 1 Gbps network within 48 hours. DMS supports ongoing replication to keep the source and target in sync, and it can use Oracle-specific features like supplemental logging and change data capture (CDC) to reduce migration time. The 1 Gbps connection provides sufficient bandwidth to transfer 5 TB in under 12 hours at full utilization, leaving ample time for setup and validation.
Variation 3. A data engineer is migrating an on-premises PostgreSQL database to Amazon RDS for PostgreSQL. The database is 2 TB in size. The engineer needs to minimize downtime. Which AWS service should be used for the migration?
easy
A.AWS Data Pipeline
✓ B.AWS Database Migration Service (DMS)
C.AWS Snowball
D.Amazon S3
Why B: AWS Database Migration Service (DMS) supports live migration with minimal downtime using change data capture. Option B is correct. Option A: S3 is for object storage, not database migration. Option C: Snowball is for large data transfer offline, which would cause downtime. Option D: Data Pipeline is for data processing workflows, not direct database migration.
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This DEA-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 DEA-C01 exam.
Question Discussion
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