DEA-C01 Data Operations and Support Practice Question
A company is using Amazon Redshift for its data warehouse. A data engineer notices that COPY commands from S3 are failing intermittently with 'S3ServiceException: Access Denied'. The IAM role used by Redshift has the correct permissions. What is the MOST likely cause?
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
✓
The S3 bucket policy denies access to the Redshift cluster's IP addresses.
S3 bucket policies may deny access even if the role allows it. Option A is wrong because the role is already attached. Option B is wrong because encryption would cause different errors. Option C is wrong because if the role exists, it should work; the issue is likely external.
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 IAM role is not attached to the Redshift cluster.
Why it's wrong here
The scenario states the role has correct permissions, implying it's attached.
- ✗
The S3 bucket uses SSE-KMS encryption and the role lacks kms:Decrypt.
Why it's wrong here
This would result in a KMS error, not S3 Access Denied.
- ✗
The IAM role name contains a typo in the COPY command.
Why it's wrong here
A typo would cause a 'role does not exist' error, not Access Denied.
- ✓
The S3 bucket policy denies access to the Redshift cluster's IP addresses.
Why this is correct
Bucket policies can override IAM permissions and cause Access Denied.
Quick reference
AWS S3 Storage Class Comparison
| Storage Class | Min Duration | Retrieval | Use Case |
|---|---|---|---|
| S3 Standard | None | Immediate | Frequently accessed data |
| S3 Standard-IA | 30 days | Immediate | Infrequent access, rapid retrieval |
| S3 One Zone-IA | 30 days | Immediate | Non-critical infrequent data |
| S3 Intelligent-Tiering | None | Immediate–hours | Unknown or changing access patterns |
| S3 Glacier Instant | 90 days | Milliseconds | Archive with instant retrieval |
| S3 Glacier Flexible | 90 days | Minutes–hours | Archive, flexible retrieval |
| S3 Glacier Deep Archive | 180 days | Hours | Long-term compliance archive |
Go deeper
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.