PCDE Monitor and optimize database performance Practice Question
This PCDE practice question tests your understanding of monitor and optimize database performance. 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.
You are monitoring a Cloud SQL for PostgreSQL instance and notice that the CPU utilization is consistently above 90% during peak hours. What is the most cost-effective initial action to reduce CPU load?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Add a read replica to offload read traffic
Adding a read replica is the most cost-effective initial action because it offloads read queries from the primary instance, reducing CPU contention without incurring the cost of upgrading the entire instance. Cloud SQL for PostgreSQL replicas use native streaming replication, so they handle read traffic while the primary focuses on writes, directly addressing high CPU utilization from read-heavy workloads.
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.
✗
Remove unnecessary indexes to reduce write overhead
Why it's wrong here
Removing indexes might increase query cost and CPU usage.
✗
Reduce the max_connections parameter to limit concurrent users
Why it's wrong here
Reducing connections may cause errors; CPU might still be high from active queries.
✓
Add a read replica to offload read traffic
Why this is correct
Read replicas handle read-only queries, reducing primary CPU load.
Related concept
Read the scenario before looking for a memorised answer.
✗
Increase the machine type (e.g., go to a higher vCPU count)
Why it's wrong here
Scaling up is costly and may not address inefficient queries.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Google Cloud often tests the misconception that vertical scaling (increasing machine type) is the default fix for high CPU, but the trap here is that adding a read replica is more cost-effective for read-heavy workloads, as it scales horizontally without upgrading the primary instance.
Detailed technical explanation
How to think about this question
Cloud SQL for PostgreSQL replicas use PostgreSQL's built-in streaming replication, where the primary streams WAL (Write-Ahead Log) segments to replicas in near real-time. This allows replicas to serve read-only queries (e.g., SELECT statements) while the primary handles writes, effectively distributing CPU load. In a real-world scenario, if 80% of queries are reads, a single replica can halve the primary's CPU usage at a fraction of the cost of doubling vCPUs.
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.
TExam Day Tips
→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 startup's cloud architect reviews their monthly bill and notices costs are higher than expected for a long-running batch job. Switching from on-demand instances to Reserved Instances — or using Spot/Preemptible VMs — can reduce compute costs by up to 72 %. Questions like this test whether you understand the tradeoffs between commitment, flexibility, and cost across cloud pricing models.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Monitor and optimize database performance — This question tests Monitor and optimize database performance — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Add a read replica to offload read traffic — Adding a read replica is the most cost-effective initial action because it offloads read queries from the primary instance, reducing CPU contention without incurring the cost of upgrading the entire instance. Cloud SQL for PostgreSQL replicas use native streaming replication, so they handle read traffic while the primary focuses on writes, directly addressing high CPU utilization from read-heavy workloads.
What should I do if I get this PCDE question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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 →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
This PCDE practice question is part of Courseiva's free Google Cloud 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 PCDE exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.