DBS-C01 Management and Operations Practice Question
A company is using Amazon DynamoDB with on-demand capacity mode. The company notices that during a flash sale, the write requests are throttled. What is the most likely cause of the throttling?
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
✓
A hot partition is causing throttling even though the table uses on-demand capacity.
For a DynamoDB table in on-demand capacity mode, throttling is typically caused by a hot partition. On-demand mode automatically scales table-level throughput, but if a single partition key is heavily accessed (e.g., during a flash sale), that partition can exceed its individual capacity limit, resulting in throttled write requests. This is the most likely cause, making option C correct. Option A (maximum throughput limit) does not apply because on-demand has no fixed maximum; option B (auto scaling) is irrelevant since on-demand manages scaling automatically; option D (provisioned WCUs) is not used in on-demand mode.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The table has reached its maximum throughput limit for on-demand mode.
Why it's wrong here
On-demand does not have a hard throughput limit; it scales automatically, but partition-level limits apply.
- ✗
The table is not configured for auto scaling.
Why it's wrong here
On-demand mode auto scales automatically, so auto scaling is not needed.
- ✓
A hot partition is causing throttling even though the table uses on-demand capacity.
Why this is correct
On-demand tables can still throttle if a single partition receives more writes than its limit (1000 writes/sec).
- ✗
The provisioned write capacity units (WCUs) are set too low.
Why it's wrong here
On-demand does not use provisioned capacity; it scales automatically.
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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.