DBS-C01 Workload-Specific Database Design Practice Question
A company is using Amazon RDS for PostgreSQL for its transactional database. The application generates reports that query millions of rows, causing high CPU on the primary instance. The reports are not time-sensitive. What is the MOST cost-effective way to offload the reporting queries without affecting write performance?
⚠ Common exam trap
Watch out — candidates often confuse Multi-AZ standby instances with Read Replicas, mistakenly believing that the standby can serve read traffic, but AWS explicitly does not allow reads from the standby in a Multi-AZ deployment.
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
✓
Create an Amazon RDS Read Replica and direct reporting queries to the replica.
Creating an Amazon RDS Read Replica offloads reporting queries to a separate read-only instance, preventing CPU contention on the primary. Since the reports are not time-sensitive, the replica can handle the large queries without impacting write performance, and it is cost-effective because you only pay for the replica's compute and storage.
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 an Amazon RDS Read Replica and direct reporting queries to the replica.
Why this is correct
Read Replicas can handle read traffic without impacting the primary.
- ✗
Use Amazon ElastiCache to cache report results.
Why it's wrong here
Caching is for repeated queries, not ad-hoc reports.
- ✗
Enable Multi-AZ to distribute reads to the standby instance.
Why it's wrong here
Multi-AZ standby does not serve reads.
- ✗
Migrate reporting to Amazon Redshift.
Why it's wrong here
Redshift is for data warehousing, not a simple offload for RDS.
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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.