The answer is that strongly consistent reads bypass the DAX cache entirely, which directly causes the low cache hit ratio. DAX is designed to accelerate read performance by caching only eventually consistent reads, meaning any request for strongly consistent data must go directly to DynamoDB’s underlying table, bypassing the cache and resulting in a miss. This concept is a frequent trap on the AWS Certified Database Specialty DBS-C01 exam, where candidates often overlook the fundamental consistency model mismatch: DAX does not support strongly consistent reads, so a sudden drop in cache hit ratio almost always points to an application switching to or heavily using strong consistency. To remember this, think of DAX as a “fast lane” for eventual consistency only—strongly consistent reads take the “local road” straight to DynamoDB, never touching the cache.
DBS-C01 Monitoring and Troubleshooting Practice Question
This DBS-C01 practice question tests your understanding of monitoring and troubleshooting. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. 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 company is using Amazon DynamoDB Accelerator (DAX) to improve read performance. Recently, the cache hit ratio has dropped significantly. The application uses strongly consistent reads. What is the most likely cause of the low cache hit ratio?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The application is using strongly consistent reads, which bypass the DAX cache
Option C is correct because DAX caches eventually consistent reads, not strongly consistent reads. Option A is wrong because TTL affects item expiration but not the consistency model. Option B is wrong because write capacity does not directly affect cache hits. Option D is wrong because the DAX cluster size affects performance but not the consistency mismatch.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
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 DynamoDB table's write capacity is too low
Why it's wrong here
Write capacity does not affect cache hit ratio.
✓
The application is using strongly consistent reads, which bypass the DAX cache
Why this is correct
DAX only caches eventually consistent reads; strongly consistent reads go directly to DynamoDB.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
The DAX cluster has too few nodes
Why it's wrong here
Cluster size affects cache capacity but not which reads are cached.
✗
The DAX cluster's TTL is set too low
Why it's wrong here
Low TTL would cause items to expire early but does not explain the consistency issue.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Detailed technical explanation
How to think about this question
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
Use explanations to understand the rule behind the answer.
TExam Day Tips
→Underline the problem statement mentally.
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A cloud solutions architect for a retail company is evaluating services for a new workload. The correct answer here reflects best practice for the specific scenario described — not a general cloud recommendation. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Cloud exam questions reward reading the constraint carefully: the same technology can be right or wrong depending on the use case.
What to study next
Got this wrong? Here's your next step.
Identify which DBS-C01 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Monitoring and Troubleshooting — This question tests Monitoring and Troubleshooting — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The application is using strongly consistent reads, which bypass the DAX cache — Option C is correct because DAX caches eventually consistent reads, not strongly consistent reads. Option A is wrong because TTL affects item expiration but not the consistency model. Option B is wrong because write capacity does not directly affect cache hits. Option D is wrong because the DAX cluster size affects performance but not the consistency mismatch.
What should I do if I get this DBS-C01 question wrong?
Identify which DBS-C01 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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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.
Question Discussion
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