- A
Query performance and latency requirements
Redshift provides fast SQL analytics; S3 queries are slower.
- B
Encryption at rest capabilities
Why wrong: Both support encryption at rest.
- C
Cost of storage vs. compute
S3 is cheaper for storage; Redshift is more expensive but includes compute.
- D
Data format and compression support
S3 supports any format; Redshift optimizes columnar formats.
- E
Data retention policies
Why wrong: Both services support lifecycle policies; not a differentiator.
Question 451 of 1,755
MLS-C01 Data Engineering Practice Question
This MLS-C01 practice question tests your understanding of data engineering. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. 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.
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.)
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.
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.
- ✓
Query performance and latency requirements
Why this is correct
Redshift provides fast SQL analytics; S3 queries are slower.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
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.
Related concept
Read the scenario before looking for a memorised answer.
- ✓
Data format and compression support
Why this is correct
S3 supports any format; Redshift optimizes columnar formats.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Data retention policies
Why it's wrong here
Both services support lifecycle policies; not a differentiator.
Common exam traps
Common exam trap: answer the scenario, not the keyword
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.
Detailed technical explanation
How to think about this question
S3 achieves low-latency access through its distributed object store and HTTP-based API, enabling parallel reads across multiple partitions. Redshift uses a columnar storage engine with zone maps and sort keys to minimize I/O for analytical queries, but its cluster architecture introduces network overhead for data loading. In practice, ML teams often store raw data in S3 (e.g., 10 TB of Parquet files) and use Redshift for feature engineering on aggregated views, then export results back to S3 for training.
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 startup's cloud architect reviews their monthly bill and notices costs are higher than expected for a long-running batch job. Switching from on-demand instances to Reserved Instances — or using Spot/Preemptible VMs — can reduce compute costs by up to 72 %. Questions like this test whether you understand the tradeoffs between commitment, flexibility, and cost across cloud pricing models.
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 |
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.
- →
Data Engineering — study guide chapter
Learn the concepts, then practise the questions
- →
Data Engineering practice questions
Targeted practice on this topic area only
- →
All MLS-C01 questions
1,755 questions across all exam domains
- →
AWS Certified Machine Learning Specialty MLS-C01 study guide
Full concept coverage aligned to exam objectives
- →
MLS-C01 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related MLS-C01 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Data Engineering practice questions
Practise MLS-C01 questions linked to Data Engineering.
Machine Learning Implementation and Operations practice questions
Practise MLS-C01 questions linked to Machine Learning Implementation and Operations.
Modeling practice questions
Practise MLS-C01 questions linked to Modeling.
Exploratory Data Analysis practice questions
Practise MLS-C01 questions linked to Exploratory Data Analysis.
MLS-C01 fundamentals practice questions
Practise MLS-C01 questions linked to MLS-C01 fundamentals.
MLS-C01 scenario practice questions
Practise MLS-C01 questions linked to MLS-C01 scenario.
MLS-C01 troubleshooting practice questions
Practise MLS-C01 questions linked to MLS-C01 troubleshooting.
Practice this exam
Start a free MLS-C01 practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this MLS-C01 question test?
Data Engineering — This question tests Data Engineering — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: 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.
What should I do if I get this MLS-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 →
Keep practising
More MLS-C01 practice questions
- A company needs to transfer 10 TB of data from an on-premises data center to Amazon S3. The network bandwidth is limited…
- A company is using Amazon Kinesis Data Streams to ingest real-time clickstream data. The data is consumed by a Lambda fu…
- A team is building a data pipeline to process terabytes of log data daily using Amazon EMR. The data arrives in 5-minute…
- A data science team is building a real-time fraud detection system. Transactions are streamed via Amazon Kinesis Data St…
- A company uses Amazon SageMaker to train and deploy machine learning models. The training data is stored in Amazon S3 (P…
- A data engineering team is designing a data lake on AWS for machine learning workloads. The data includes structured, se…
Last reviewed: Jul 4, 2026
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.
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.
Sign in to join the discussion.