MLS-C01 Data Engineering Practice Question
Which THREE factors should a data engineer consider when choosing between Amazon S3 and Amazon Redshift for storing large datasets used for machine learning? (Choose 3.)
⚠ Common exam trap
A common mistake is assuming encryption or retention policies are unique to one service, when in fact both S3 and Redshift offer equivalent capabilities, making them irrelevant for this comparison.
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
✓
Query performance and latency requirements
When choosing between Amazon S3 and Amazon Redshift for ML data storage, key considerations include: (A) Query performance and latency: Redshift offers low-latency SQL querying on structured data, while S3 provides higher latency for direct access, making performance needs critical. (C) Cost of storage vs. compute: S3 decouples storage and compute, allowing independent scaling; Redshift combines them, affecting cost. (D) Data format and compression: S3 supports any format, but Redshift works best with columnar formats like Parquet. (B) Encryption at rest and (E) Data retention policies are available in both, so they are not differentiating factors.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Query performance and latency requirements
Why this is correct
Redshift provides fast SQL analytics; S3 queries are slower.
- ✗
Encryption at rest capabilities
Why it's wrong here
Both support encryption at rest.
- ✓
Cost of storage vs. compute
Why this is correct
S3 is cheaper for storage; Redshift is more expensive but includes compute.
- ✓
Data format and compression support
Why this is correct
S3 supports any format; Redshift optimizes columnar formats.
- ✗
Data retention policies
Why it's wrong here
Both services support lifecycle policies; not a differentiator.
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 MLS-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 MLS-C01 exam.