← DBS-C01·Amazon Web Services

Question 1,600 of 1,730

Deployment and Migration →hardMultiple ChoiceObjective-mapped

DBS-C01 Deployment and Migration Practice Question

This DBS-C01 practice question tests your understanding of deployment and migration. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. 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.

Exhibit

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "dms:CreateEndpoint",
        "dms:ModifyEndpoint",
        "dms:DescribeEndpoints"
      ],
      "Resource": "*"
    },
    {
      "Effect": "Allow",
      "Action": [
        "rds:DescribeDBInstances",
        "rds:ModifyDBInstance"
      ],
      "Resource": "arn:aws:rds:us-east-1:123456789012:db:target-db"
    }
  ]
}

A team is setting up a DMS migration task. The IAM policy above is attached to the DMS replication instance's IAM role. The team is unable to modify the target RDS instance's maintenance window during the migration. Which additional permission is missing?

Question 1hardmultiple choice

Full question →

Exhibit

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "dms:CreateEndpoint",
        "dms:ModifyEndpoint",
        "dms:DescribeEndpoints"
      ],
      "Resource": "*"
    },
    {
      "Effect": "Allow",
      "Action": [
        "rds:DescribeDBInstances",
        "rds:ModifyDBInstance"
      ],
      "Resource": "arn:aws:rds:us-east-1:123456789012:db:target-db"
    }
  ]
}

A
Add 'rds:ModifyDBInstance' permission for the source RDS instance.
The policy only allows modification of the target instance; the source instance also needs to be modified during migration, e.g., enabling binary logging.
B
Add 'rds:ModifyOptionGroup' permission for the target RDS instance.
Why wrong: Modifying the option group is different from modifying the maintenance window; the maintenance window is part of rds:ModifyDBInstance.
C
Add 'dms:ModifyReplicationInstance' permission for the DMS replication instance.
Why wrong: The maintenance window is a property of the RDS instance, not the DMS replication instance.
D
Add 'ec2:DescribeVpcs' permission to the policy.
Why wrong: VPC permissions are not needed to modify the RDS maintenance window.

Full breakdown with real-world context →

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

✓

Add 'rds:ModifyDBInstance' permission for the source RDS instance.

The correct answer is A because modifying the target RDS instance's maintenance window requires the `rds:ModifyDBInstance` permission. The DMS replication instance's IAM role must have this permission for the target RDS instance to allow the migration task to adjust the maintenance window, which is necessary to prevent conflicts during ongoing replication. Without this permission, the DMS task cannot alter the maintenance window, even if the IAM role has other RDS permissions.

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.

✓
Add 'rds:ModifyDBInstance' permission for the source RDS instance.
Why this is correct
The policy only allows modification of the target instance; the source instance also needs to be modified during migration, e.g., enabling binary logging.
Related concept
Read the scenario before looking for a memorised answer.
✗
Add 'rds:ModifyOptionGroup' permission for the target RDS instance.
Why it's wrong here
Modifying the option group is different from modifying the maintenance window; the maintenance window is part of rds:ModifyDBInstance.
✗
Add 'dms:ModifyReplicationInstance' permission for the DMS replication instance.
Why it's wrong here
The maintenance window is a property of the RDS instance, not the DMS replication instance.
✗
Add 'ec2:DescribeVpcs' permission to the policy.
Why it's wrong here
VPC permissions are not needed to modify the RDS maintenance window.

Common exam traps

Common exam trap: answer the scenario, not the keyword

The trap here is that candidates may confuse the permissions needed for modifying the target RDS instance's maintenance window with permissions for modifying the DMS replication instance or RDS option groups, leading them to select options B or C instead of the correct `rds:ModifyDBInstance` permission.

Detailed technical explanation

How to think about this question

The `rds:ModifyDBInstance` API call is required to change the `PreferredMaintenanceWindow` parameter of an RDS instance. DMS migration tasks often need to adjust the target instance's maintenance window to avoid overlapping with the migration's ongoing replication window, especially for large migrations where continuous data replication is critical. Without this permission, the DMS task will fail with an authorization error when attempting to modify the maintenance window, even if the IAM role has other RDS permissions like `rds:DescribeDBInstances`.

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 company's IT admin needs to give a contractor read-only access to production logs without sharing account credentials. Using role-based access control (RBAC) and temporary scoped permissions — not a permanent shared password — is the correct pattern. Questions like this test whether you can apply least-privilege access across cloud identity services.

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.

Related DBS-C01 practice-question pages

Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.

Workload-Specific Database Design practice questions

Practise DBS-C01 questions linked to Workload-Specific Database Design.

Deployment and Migration practice questions

Practise DBS-C01 questions linked to Deployment and Migration.

Management and Operations practice questions

Practise DBS-C01 questions linked to Management and Operations.

Monitoring and Troubleshooting practice questions

Practise DBS-C01 questions linked to Monitoring and Troubleshooting.

Database Security practice questions

Practise DBS-C01 questions linked to Database Security.

DBS-C01 fundamentals practice questions

Practise DBS-C01 questions linked to DBS-C01 fundamentals.

DBS-C01 scenario practice questions

Practise DBS-C01 questions linked to DBS-C01 scenario.

DBS-C01 troubleshooting practice questions

Practise DBS-C01 questions linked to DBS-C01 troubleshooting.

Practice this exam

Start a free DBS-C01 practice session

Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.

10 questions 20 questions 30 questions 50 questions Timed 30

DBS-C01 practice-test guide →Study guide →Browse all practice tests

FAQ

Questions learners often ask

What does this DBS-C01 question test?

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: Add 'rds:ModifyDBInstance' permission for the source RDS instance. — The correct answer is A because modifying the target RDS instance's maintenance window requires the `rds:ModifyDBInstance` permission. The DMS replication instance's IAM role must have this permission for the target RDS instance to allow the migration task to adjust the maintenance window, which is necessary to prevent conflicts during ongoing replication. Without this permission, the DMS task cannot alter the maintenance window, even if the IAM role has other RDS permissions.

What should I do if I get this DBS-C01 question wrong?

Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.

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 →

How Courseiva writes practice questions · Editorial policy

Last reviewed: Jun 11, 2026

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.

Loading comments…

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.