DBS-C01 Workload-Specific Database Design Practice Question
A company is migrating an on-premises MongoDB database to Amazon DocumentDB. The database stores IoT sensor data with time-series characteristics. The application performs range queries on timestamp fields and updates recent documents frequently. Which THREE aspects of DocumentDB should the company consider to optimize performance for this workload? (Choose three.)
⚠ Common exam trap
A common mix-up: candidates assume DocumentDB supports sharding natively like MongoDB, but DocumentDB does not have built-in sharding; instead, you must implement application-level sharding or use multiple clusters to distribute write load.
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
✓
Implement sharding to distribute write load across multiple instances.
DocumentDB does not support native sharding like MongoDB; however, for workloads with high write throughput, you can distribute writes by using multiple DocumentDB instances and routing writes based on a shard key in the application layer. This helps avoid write bottlenecks on a single instance and scales write capacity horizontally.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Use global secondary indexes to speed up queries on the timestamp field.
Why it's wrong here
DocumentDB does not support global secondary indexes; it uses standard secondary indexes.
- ✓
Implement sharding to distribute write load across multiple instances.
Why this is correct
Sharding helps scale writes by distributing data across shards.
- ✓
Enable a TTL index on the timestamp field to automatically delete old data.
Why this is correct
TTL indexes help manage data lifecycle and keep the collection size manageable.
- ✓
Create a compound index on (device_id, timestamp) to support range queries.
Why this is correct
Compound indexes improve performance for queries that filter on both fields.
- ✗
Use a single large instance class to avoid sharding complexity.
Why it's wrong here
For high write throughput, sharding is more scalable than a single large instance.
Go deeper
Related to this question
About these practice questions
Courseiva writes every DBS-C01 question from scratch — 1,663 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DBS-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 DBS-C01 exam.