Question 297 of 1,672
Amazon Athena for Serverless SQL Queries on S3
A data scientist needs to run ad-hoc SQL queries on a large dataset stored in Amazon S3 (Parquet format, 2 TB). The queries are interactive and require sub-second response times. Which service should they use?
Quick Answer
The answer is Amazon Athena, the correct choice for running serverless SQL queries on S3 with sub-second response times. Athena directly queries data in place using standard SQL, and when data is stored in columnar formats like Parquet, it leverages partitioning and predicate pushdown to minimize data scanned, enabling fast interactive performance without any infrastructure to manage. On the AWS Certified Machine Learning Specialty MLS-C01 exam, this scenario tests your understanding of serverless analytics versus managed clusters: Athena is ideal for ad-hoc, low-latency queries on S3, while EMR requires cluster provisioning and Redshift Spectrum is better suited for heavy, persistent workloads. A common trap is choosing Redshift Spectrum for its speed, but for truly ad-hoc interactive queries with no setup, Athena is the lighter, more direct fit. Memory tip: think “Athena on S3, no cluster for me.”
⚠ Common exam trap
A common mix-up: candidates confuse Amazon Athena with Amazon Redshift Spectrum, assuming both are equally serverless, but Spectrum still requires a provisioned Redshift cluster, whereas Athena is truly serverless and pay-per-query.
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
✓
Amazon Athena
Amazon Athena is the correct choice because it is a serverless, interactive query service designed for ad-hoc SQL queries on data stored in Amazon S3, with no infrastructure to manage. It natively supports Parquet format and can achieve sub-second response times on 2 TB datasets through columnar projection, predicate pushdown, and data partitioning, making it ideal for this use case.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Amazon Redshift Spectrum
Why it's wrong here
Redshift Spectrum requires a Redshift cluster, not serverless ad-hoc.
- ✗
Amazon QuickSight
Why it's wrong here
QuickSight is for visualization, not direct SQL queries.
- ✗
Amazon EMR with Spark SQL
Why it's wrong here
EMR requires provisioning and startup time, not ideal for ad-hoc interactive queries.
- ✓
Amazon Athena
Why this is correct
Athena is serverless and optimized for interactive queries on S3 data.
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 |
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 →
Same concept, more angles
3 more ways this is tested on MLS-C01
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 scientist wants to explore a large dataset stored in Amazon S3 using SQL queries without moving the data. The dataset is in CSV format and is updated daily with new partitions. Which AWS service should be used to directly query the data in S3?
easy- ✓ A.Amazon Athena
- B.Amazon Redshift Spectrum
- C.Amazon EMR
- D.AWS Glue
Why A: Amazon Athena is a serverless interactive query service that allows you to analyze data directly in Amazon S3 using standard SQL, without needing to load or transform the data. It supports CSV format and can automatically discover new partitions when used with Hive-style partitioning and the MSCK REPAIR TABLE command or by enabling partition projection. This makes it the ideal choice for directly querying a large, daily-updated CSV dataset stored in S3.
Variation 2. A data scientist needs to run a one-time SQL query on a large dataset in Amazon S3. The dataset is stored in Parquet format and is about 500 GB. The query requires complex aggregations and joins. Which AWS service should be used to minimize cost and setup time?
easy- A.Amazon Redshift
- ✓ B.Amazon Athena
- C.Amazon RDS for MySQL
- D.Amazon EMR with Spark SQL
Why B: Amazon Athena is the correct choice because it is a serverless query service that allows you to run SQL directly on data stored in S3 without provisioning any infrastructure. For a one-time query on 500 GB of Parquet data, Athena minimizes cost (pay-per-query, no idle cluster costs) and setup time (no cluster creation or data loading). Its ability to handle complex aggregations and joins on columnar formats like Parquet makes it ideal for this ad-hoc use case.
Variation 3. A data scientist wants to query a dataset stored in Amazon S3 using standard SQL without provisioning any servers. The dataset is in CSV format and is updated daily. Which AWS service should be used?
easy- ✓ A.Amazon Athena
- B.Amazon Redshift
- C.Amazon RDS
- D.Amazon DynamoDB
Why A: Amazon Athena is a serverless interactive query service that allows you to query data directly from Amazon S3 using standard SQL without provisioning any servers. It is ideal for querying CSV datasets that are updated daily because it supports schema-on-read, meaning you can define the table schema at query time without loading or transforming the data beforehand.
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.