CLF-C02 Cloud Technology and Services Practice Question
A company runs a real-time bidding platform for online advertising. The platform requires a database that can handle millions of requests per second with single-digit millisecond latency for both reads and writes. The data model is simple key-value pairs, and the database must be fully managed so that the company does not have to provision or maintain servers. Which AWS database service should the company use to meet these requirements?
⚠ Common exam trap
A common mix-up: candidates confuse ElastiCache (a caching layer) with a primary database, overlooking DynamoDB's fully managed, serverless nature and its native support for high-throughput key-value workloads with persistent storage.
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 DynamoDB
Amazon DynamoDB is the correct choice because it is a fully managed NoSQL key-value and document database that delivers single-digit millisecond latency at any scale, handling millions of requests per second. Its serverless architecture eliminates the need to provision or manage servers, making it ideal for real-time bidding platforms with simple key-value data models and high-throughput, low-latency requirements.
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 RDS
Why it's wrong here
Amazon RDS is a managed relational database service. It supports traditional SQL databases like MySQL and PostgreSQL, but it is not designed for key-value workloads requiring millions of requests per second with single-digit millisecond latency. Scaling to that level with RDS would require complex sharding and still may not meet the latency requirements.
When this WOULD be correct
A company needs a fully managed relational database for a traditional web application with moderate read/write throughput, requiring complex SQL queries, joins, and transactions, and is willing to manage scaling via read replicas and instance sizing.
- ✓
Amazon DynamoDB
Why this is correct
Amazon DynamoDB is a fully managed NoSQL key-value and document database that delivers single-digit millisecond latency at any scale. It automatically scales to handle millions of requests per second and requires no server provisioning, making it the perfect fit for a real-time bidding platform with high-throughput, low-latency key-value access.
- ✗
Amazon Redshift
Why it's wrong here
Amazon Redshift is a petabyte-scale data warehouse service optimized for complex analytical queries on large datasets. It is not suitable for real-time, high-throughput key-value workloads requiring microsecond or single-digit millisecond latency. Redshift is designed for batch processing and reporting, not for transactional or interactive low-latency access.
When this WOULD be correct
A company needs to run complex SQL queries and aggregations on petabytes of structured data for business intelligence and reporting, and requires a fully managed, petabyte-scale data warehouse solution.
- ✗
Amazon ElastiCache
Why it's wrong here
Amazon ElastiCache provides in-memory caching using Redis or Memcached. While it offers low latency, it is not a durable primary database; data is stored in memory and can be lost on failure. For a real-time bidding platform that requires data persistence, ElastiCache serves best as a cache in front of a database like DynamoDB, not as the primary data store.
When this WOULD be correct
A company needs to accelerate access to a relational database by caching frequently accessed query results, reducing read latency for a high-traffic web application. The database must be fully managed and support sub-millisecond response times for cached data.
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 DynamoDBCorrect answer▾
Why this is correct
Amazon DynamoDB is a fully managed NoSQL key-value and document database that delivers single-digit millisecond latency at any scale. It automatically scales to handle millions of requests per second and requires no server provisioning, making it the perfect fit for a real-time bidding platform with high-throughput, low-latency key-value access.
✗Amazon RDSWrong answer — click to see why▾
Why this is wrong here
Amazon RDS is a relational database service that does not provide single-digit millisecond latency for millions of requests per second, nor does it natively support simple key-value data models at that scale without extensive caching and read replicas.
★ When this WOULD be the correct answer
A company needs a fully managed relational database for a traditional web application with moderate read/write throughput, requiring complex SQL queries, joins, and transactions, and is willing to manage scaling via read replicas and instance sizing.
Why candidates choose this
Candidates may assume that 'fully managed database' implies RDS, and they might overlook the specific performance and data model requirements (key-value, high throughput, low latency) that DynamoDB is designed for.
✗Amazon RedshiftWrong answer — click to see why▾
Why this is wrong here
Amazon Redshift is a data warehouse optimized for analytical queries on large datasets, not for real-time key-value workloads requiring single-digit millisecond latency at millions of requests per second.
★ When this WOULD be the correct answer
A company needs to run complex SQL queries and aggregations on petabytes of structured data for business intelligence and reporting, and requires a fully managed, petabyte-scale data warehouse solution.
Why candidates choose this
Candidates may confuse 'database' with 'data warehouse' and assume Redshift can handle high-throughput, low-latency transactions, overlooking its design for batch analytics rather than real-time operational workloads.
✗Amazon ElastiCacheWrong answer — click to see why▾
Why this is wrong here
Amazon ElastiCache is an in-memory caching service, not a fully managed database for persistent key-value storage. It is designed to cache data to reduce latency, but it does not provide the durability and persistence required for a primary database in a real-time bidding platform.
★ When this WOULD be the correct answer
A company needs to accelerate access to a relational database by caching frequently accessed query results, reducing read latency for a high-traffic web application. The database must be fully managed and support sub-millisecond response times for cached data.
Why candidates choose this
Candidates may confuse ElastiCache's low-latency, in-memory capabilities with DynamoDB's single-digit millisecond performance, overlooking that ElastiCache is not a persistent database but a cache layer.
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?”
Quick reference
Cloud Service Model Comparison
| Model | You Manage | Provider Manages | Examples |
|---|---|---|---|
| IaaS | OS, runtime, apps, data | Hardware, hypervisor, networking | EC2, Azure VMs, GCP Compute Engine |
| PaaS | Apps and data | OS, runtime, middleware, hardware | Elastic Beanstalk, Azure App Service |
| SaaS | Data and settings only | Everything else | Microsoft 365, Salesforce, Workday |
| FaaS / Serverless | Function code only | Infra, scaling, runtime | Lambda, Azure Functions, Cloud Run |
| CaaS | Containers and apps | Kubernetes, OS, hardware | EKS, AKS, GKE |
Go deeper
Related to this question
About these practice questions
One of 988 original CLF-C02 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.