- A
Amazon DynamoDB
Why wrong: Amazon DynamoDB is a fully managed NoSQL database that provides single-digit millisecond latency for key-value and document workloads. While it can store time-series data using techniques like time-to-live and write sharding, it lacks built-in time-series analytics functions and is less optimized for the high-ingestion rates and query patterns typical of IoT sensor data. It is not the best choice for this use case.
- B
Amazon Timestream
Amazon Timestream is a purpose-built time-series database that can efficiently ingest, store, and analyze trillions of time-stamped data points per day. It is serverless and auto-scaling, with built-in time-series analytics functions such as interpolation, smoothing, and approximation. This makes it the ideal choice for the company's IoT sensor data requirements.
- C
Amazon ElastiCache for Redis
Why wrong: Amazon ElastiCache for Redis is an in-memory caching service that provides sub-millisecond latency for caching and session management use cases. It is not designed for persistent storage of large volumes of time-series data, nor does it provide built-in time-series analytics capabilities. It would be an inefficient and costly choice for this workload.
- D
Amazon RDS for MySQL
Why wrong: Amazon RDS for MySQL is a managed relational database service suitable for traditional transactional workloads. While it can store time-series data, it is not optimized for the extreme write throughput and storage scalability required for thousands of IoT devices generating data every second. Additionally, it lacks specialized time-series query functions and would require significant manual optimization.
CLF-C02 Cloud Technology and Services Practice Question
This CLF-C02 practice question tests your understanding of cloud technology and services. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. 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.
A manufacturing company collects sensor data from thousands of IoT devices every second. The data includes temperature, pressure, and vibration readings. The company needs to store this time-series data and perform real-time queries to detect anomalies, as well as run historical analysis. The data volume is extremely high and will grow continuously. The company wants a fully managed, serverless solution that can automatically scale to handle the data volume and provide built-in analytics functions for time-series. Which AWS service should the company use?
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 Timestream
Amazon Timestream is a fully managed, serverless time-series database service designed specifically for IoT and operational applications. It automatically scales to handle trillions of events per day, provides built-in time-series analytics functions (e.g., smoothing, approximation, interpolation), and supports both real-time queries and historical analysis with separate storage tiers (in-memory for recent data and magnetic for historical data). This makes it the ideal choice for the company's high-volume sensor data requirements.
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.
- ✗
Amazon DynamoDB
Why it's wrong here
Amazon DynamoDB is a fully managed NoSQL database that provides single-digit millisecond latency for key-value and document workloads. While it can store time-series data using techniques like time-to-live and write sharding, it lacks built-in time-series analytics functions and is less optimized for the high-ingestion rates and query patterns typical of IoT sensor data. It is not the best choice for this use case.
When this WOULD be correct
A company needs a fully managed NoSQL database for a web application that requires single-digit millisecond latency at any scale, with flexible schema for user profiles and session data, and can handle high traffic with auto-scaling.
- ✓
Amazon Timestream
Why this is correct
Amazon Timestream is a purpose-built time-series database that can efficiently ingest, store, and analyze trillions of time-stamped data points per day. It is serverless and auto-scaling, with built-in time-series analytics functions such as interpolation, smoothing, and approximation. This makes it the ideal choice for the company's IoT sensor data requirements.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Amazon ElastiCache for Redis
Why it's wrong here
Amazon ElastiCache for Redis is an in-memory caching service that provides sub-millisecond latency for caching and session management use cases. It is not designed for persistent storage of large volumes of time-series data, nor does it provide built-in time-series analytics capabilities. It would be an inefficient and costly choice for this workload.
- ✗
Amazon RDS for MySQL
Why it's wrong here
Amazon RDS for MySQL is a managed relational database service suitable for traditional transactional workloads. While it can store time-series data, it is not optimized for the extreme write throughput and storage scalability required for thousands of IoT devices generating data every second. Additionally, it lacks specialized time-series query functions and would require significant manual optimization.
When this WOULD be correct
A company needs a fully managed relational database for a traditional OLTP application with structured data, ACID transactions, and complex joins, and requires MySQL compatibility for existing applications.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The CLF-C02 exam frequently reuses these exact scenarios with slightly different constraints.
✓Amazon TimestreamCorrect answer▾
Why this is correct
Amazon Timestream is a purpose-built time-series database that can efficiently ingest, store, and analyze trillions of time-stamped data points per day. It is serverless and auto-scaling, with built-in time-series analytics functions such as interpolation, smoothing, and approximation. This makes it the ideal choice for the company's IoT sensor data requirements.
✗Amazon DynamoDBWrong answer — click to see why▾
Why this is wrong here
DynamoDB is a key-value and document database, not optimized for time-series data. It lacks built-in time-series analytics functions and can become expensive and complex to manage for high-frequency sensor data with continuous growth.
★ When this WOULD be the correct answer
A company needs a fully managed NoSQL database for a web application that requires single-digit millisecond latency at any scale, with flexible schema for user profiles and session data, and can handle high traffic with auto-scaling.
Why candidates choose this
Candidates may think DynamoDB's scalability and serverless nature make it suitable for IoT data, but they overlook that it is not purpose-built for time-series workloads and lacks native time-series functions.
✗Amazon RDS for MySQLWrong answer — click to see why▾
Why this is wrong here
Amazon RDS for MySQL is a relational database not optimized for time-series data; it lacks built-in time-series analytics functions and auto-scaling for high-velocity IoT data, requiring manual sharding and indexing.
★ When this WOULD be the correct answer
A company needs a fully managed relational database for a traditional OLTP application with structured data, ACID transactions, and complex joins, and requires MySQL compatibility for existing applications.
Why candidates choose this
Candidates may assume any database can handle time-series data and overlook the specialized requirements, or they may be more familiar with RDS and underestimate the need for a purpose-built service.
Analysis generated from the official CLF-C02blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often choose DynamoDB (Option A) because they associate it with high-scale IoT workloads, but they overlook the requirement for built-in time-series analytics functions and automatic tiered storage, which Timestream uniquely provides as a purpose-built time-series database.
Detailed technical explanation
How to think about this question
Amazon Timestream uses a purpose-built storage engine that separates recent data (stored in memory for fast queries) from historical data (stored cost-effectively on magnetic storage), automatically moving data between tiers based on configurable retention policies. It supports standard SQL with time-series extensions such as `SMOOTH`, `INTERPOLATE`, and `FILL`, enabling anomaly detection and trend analysis without custom code. In real-world IoT scenarios, this allows the company to query the last hour of vibration data in milliseconds while running complex aggregation queries on years of temperature data without performance degradation.
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 media company stores terabytes of video archives that are accessed once a year for audit purposes. Moving these objects to a cold storage tier (Azure Archive, S3 Glacier, or Google Nearline) costs a fraction of hot storage. Questions like this test whether you understand storage tiers, access frequency tradeoffs, and retrieval latency requirements.
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.
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FAQ
Questions learners often ask
What does this CLF-C02 question test?
Cloud Technology and Services — This question tests Cloud Technology and Services — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Amazon Timestream — Amazon Timestream is a fully managed, serverless time-series database service designed specifically for IoT and operational applications. It automatically scales to handle trillions of events per day, provides built-in time-series analytics functions (e.g., smoothing, approximation, interpolation), and supports both real-time queries and historical analysis with separate storage tiers (in-memory for recent data and magnetic for historical data). This makes it the ideal choice for the company's high-volume sensor data requirements.
What should I do if I get this CLF-C02 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 →
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Last reviewed: Jun 11, 2026
This CLF-C02 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 CLF-C02 exam.
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