Quick Answer
The answer is Amazon DynamoDB. This is the correct choice because DynamoDB is purpose-built as a key-value and document database, offering single-digit millisecond latency at any scale, which makes it ideal for JSON key-value storage with low latency. It natively supports JSON documents and provides fast, predictable performance for simple key-based access patterns without the overhead of complex querying. On the AWS Certified Data Engineer Associate DEA-C01 exam, this question tests your ability to match workload characteristics to the right service: DynamoDB for high-throughput, low-latency key-value access, versus RDS for relational queries, S3 for object storage with higher read latency, and ElastiCache for caching rather than durable primary storage. A common trap is choosing S3 for JSON storage, but S3’s eventual consistency and higher per-request latency make it unsuitable for frequently accessed, low-latency web applications. Memory tip: think “Key-Value + Low Latency = DynamoDB” — if the access pattern is “give me this one thing fast,” DynamoDB is your answer.
This DEA-C01 practice question tests your understanding of data store management. 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 data engineer needs to store JSON documents that are frequently accessed by a low-latency web application. The data does not require complex queries, and the access pattern is primarily by a key. Which AWS service is most appropriate?
Amazon ElastiCache for Redis
Why wrong: ElastiCache is a cache, not a durable primary data store.
Amazon S3
Why wrong: S3 has higher latency for frequent reads compared to DynamoDB.
Amazon RDS for MySQL
Why wrong: RDS is relational and not ideal for simple key-value access.
Amazon DynamoDB
DynamoDB provides low-latency key-value access for JSON documents.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
Amazon DynamoDB
Option A is correct because Amazon DynamoDB is a key-value and document database that offers low-latency access. Option B (RDS) is relational and not optimized for JSON. Option C (S3) has higher latency for frequent reads. Option D (ElastiCache) is a cache, not a primary store.
Key principle: NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
Amazon ElastiCache for Redis
Why it's wrong here
ElastiCache is a cache, not a durable primary data store.
Amazon S3
Why it's wrong here
S3 has higher latency for frequent reads compared to DynamoDB.
Amazon RDS for MySQL
Why it's wrong here
RDS is relational and not ideal for simple key-value access.
Amazon DynamoDB
Common exam traps
NAT is not only about the public address. The inside/outside interface roles and the ACL or rule that matches traffic are just as important.
Detailed technical explanation
NAT questions usually test address translation, overload/PAT behaviour, static mappings and whether the right traffic is being translated. Read the interface direction and address terms carefully.
Key takeaway
NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
Real-world example
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.
What to study next
Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related DEA-C01 NAT questions on configuration and troubleshooting.
Data Store Management — study guide chapter
Learn the concepts, then practise the questions
Data Store Management practice questions
Targeted practice on this topic area only
All DEA-C01 questions
1,786 questions across all exam domains
AWS Certified Data Engineer Associate DEA-C01 study guide
Full concept coverage aligned to exam objectives
DEA-C01 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Practise DEA-C01 questions linked to Data Ingestion and Transformation.
Practise DEA-C01 questions linked to Data Operations and Support.
Practise DEA-C01 questions linked to Data Security and Governance.
Practise DEA-C01 questions linked to Data Store Management.
Practise DEA-C01 questions linked to DEA-C01 fundamentals.
Practise DEA-C01 questions linked to DEA-C01 scenario.
Practise DEA-C01 questions linked to DEA-C01 troubleshooting.
Practice this exam
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Data Store Management — This question tests Data Store Management — Static NAT maps one inside address to one outside address..
The correct answer is: Amazon DynamoDB — Option A is correct because Amazon DynamoDB is a key-value and document database that offers low-latency access. Option B (RDS) is relational and not optimized for JSON. Option C (S3) has higher latency for frequent reads. Option D (ElastiCache) is a cache, not a primary store.
Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related DEA-C01 NAT questions on configuration and troubleshooting.
Static NAT maps one inside address to one outside address.
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
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 engineer needs to store JSON documents that are frequently read and written by a web application. The data has a flexible schema and requires low-latency queries on primary key lookups. Which AWS service is MOST suitable?
easyWhy C: Option B is correct because DynamoDB is a NoSQL database designed for low-latency key-value lookups with flexible schema. Option A is wrong because RDS is relational and requires fixed schema. Option C is wrong because S3 is object storage, not designed for low-latency primary key lookups. Option D is wrong because Redshift is a data warehouse for analytics, not transactional workloads.
Keep practising
Last reviewed: Jun 20, 2026
This DEA-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 DEA-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.