The correct answer is to create a DynamoDB table with partition key = customer_id and sort key = timestamp. This design directly mirrors the composite row key from HBase by using customer_id as the partition key to distribute data evenly across partitions, while timestamp as the sort key enables efficient range queries to retrieve the latest entries per customer using the Query API with ScanIndexForward set to false. On the AWS Certified Data Engineer Associate DEA-C01 exam, this scenario tests your understanding of DynamoDB table key design, specifically how composite partition and sort keys optimize access patterns by avoiding hot partitions—a common trap where candidates mistakenly use timestamp as the partition key, causing uneven load. Remember the memory tip: “Partition for distribution, sort for ordering”—the partition key spreads the load, while the sort key supports time-based retrieval without sacrificing performance.
DEA-C01 Data Store Management Practice Question
This DEA-C01 practice question tests your understanding of data store management. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. 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 is migrating an on-premises Apache HBase workload to Amazon DynamoDB. The HBase table has a row key with composite structure: customer_id (10 chars) + timestamp (10 digits). The access pattern is to query by customer_id and retrieve the latest entries. How should the DynamoDB table be designed to optimize performance?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Create a table with partition key = customer_id and sort key = timestamp.
Option A is correct because using customer_id as partition key and timestamp as sort key allows efficient queries for latest entries per customer. Option B is incorrect because using timestamp as partition key leads to hot partitions. Option C is incorrect because a single partition key cannot support range queries efficiently. Option D is incorrect because S3 is not suitable for low-latency queries.
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
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✓
Create a table with partition key = customer_id and sort key = timestamp.
Why this is correct
Allows querying by customer_id and sorting by timestamp to get latest entries.
Related concept
Static NAT maps one inside address to one outside address.
✗
Use Amazon S3 with customer_id as prefix and timestamp as object name.
Why it's wrong here
S3 is not designed for low-latency queries like DynamoDB.
✗
Create a table with partition key = concatenated customer_id and timestamp.
Why it's wrong here
Cannot query by customer_id alone; would require full scan.
✗
Create a table with partition key = timestamp and sort key = customer_id.
Why it's wrong here
This would scatter data across partitions and make queries inefficient.
Common exam traps
Common exam trap: NAT rules depend on direction and matching traffic
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
How to think about this question
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.
KKey Concepts to Remember
Static NAT maps one inside address to one outside address.
PAT allows many inside hosts to share one public address using ports.
Inside local and inside global describe the private and translated addresses.
NAT ACLs identify traffic for translation, not always security filtering.
TExam Day Tips
→Identify inside and outside interfaces first.
→Check whether the scenario needs static NAT, dynamic NAT or PAT.
→Do not confuse NAT matching ACLs with normal packet-filtering intent.
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
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.
What to study next
Got this wrong? Here's your next step.
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 — This question tests Data Store Management — Static NAT maps one inside address to one outside address..
What is the correct answer to this question?
The correct answer is: Create a table with partition key = customer_id and sort key = timestamp. — Option A is correct because using customer_id as partition key and timestamp as sort key allows efficient queries for latest entries per customer. Option B is incorrect because using timestamp as partition key leads to hot partitions. Option C is incorrect because a single partition key cannot support range queries efficiently. Option D is incorrect because S3 is not suitable for low-latency queries.
What should I do if I get this DEA-C01 question wrong?
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.
What is the key concept behind this question?
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 →
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 is migrating an on-premises Apache HBase workload to Amazon DynamoDB. The application requires strongly consistent reads and the ability to query by a composite key (partition key + sort key). Which DynamoDB table design should be used?
medium
✓ A.Create a table with a partition key and sort key, and use ConsistentRead parameter.
B.Use a secondary index with strongly consistent reads.
C.Use a local secondary index (LSI) with the composite key.
D.Create a global secondary index (GSI) with the composite key.
Why A: DynamoDB natively supports strongly consistent reads when you use the `ConsistentRead` parameter set to `true` on GetItem, Query, or Scan operations. By defining a table with a partition key and sort key, you can directly query by the composite key (partition key + sort key) with strong consistency, meeting both requirements without additional infrastructure.
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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
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