- A
Upgrade the primary instance to a higher machine type
Why wrong: Vertical scaling helps but is not as cost-effective as read replicas for read-heavy workloads.
- B
Optimize slow queries using EXPLAIN ANALYZE and add indexes
Why wrong: This improves query performance but does not scale to handle increased read traffic.
- C
Enable connection pooling with Cloud SQL Auth Proxy and PgBouncer
Why wrong: Connection pooling reduces connection overhead but does not offload read queries from the primary.
- D
Create Cloud SQL read replicas and direct read-only queries to them
Read replicas serve read traffic without impacting primary instance performance, and minimal application changes are needed.
Question 111 of 1,000
PCDE Optimising Service Performance Practice Question
This PCDE practice question tests your understanding of optimising service performance. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. 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 team runs a Cloud SQL MySQL instance serving an e-commerce application. Read traffic is growing and causing increased latency on the primary instance. They want to offload read queries with minimal application changes. Which solution should they implement?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"primary"Why it matters: Asks for the main purpose or function, not a secondary benefit. Eliminate answers that describe side-effects or partial functions.
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 Cloud SQL read replicas and direct read-only queries to them
Cloud SQL read replicas are designed to offload read traffic from the primary instance. The application can be configured to send read-only queries to the replica endpoint. Connection pooling with PgBouncer helps with connection management but does not offload reads. Query optimization reduces load but doesn't scale reads. Read replicas are the standard solution.
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.
- ✗
Upgrade the primary instance to a higher machine type
Why it's wrong here
Vertical scaling helps but is not as cost-effective as read replicas for read-heavy workloads.
- ✗
Optimize slow queries using EXPLAIN ANALYZE and add indexes
Why it's wrong here
This improves query performance but does not scale to handle increased read traffic.
- ✗
Enable connection pooling with Cloud SQL Auth Proxy and PgBouncer
Why it's wrong here
Connection pooling reduces connection overhead but does not offload read queries from the primary.
- ✓
Create Cloud SQL read replicas and direct read-only queries to them
Why this is correct
Read replicas serve read traffic without impacting primary instance performance, and minimal application changes are needed.
Clue confirmation
The clue word "primary" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
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
An e-commerce site experiences heavy traffic on Black Friday and near-zero traffic during off-peak weeks. Rather than provisioning permanent large VMs, the team uses auto-scaling groups that add capacity automatically under load and reduce it overnight. Questions like this test whether you understand elasticity, availability zones, and cloud compute scaling patterns.
What to study next
Got this wrong? Here's your next step.
Identify which PCDE 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.
- →
Optimising Service Performance — study guide chapter
Learn the concepts, then practise the questions
- →
Optimising Service Performance practice questions
Targeted practice on this topic area only
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FAQ
Questions learners often ask
What does this PCDE question test?
Optimising Service Performance — This question tests Optimising Service Performance — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Create Cloud SQL read replicas and direct read-only queries to them — Cloud SQL read replicas are designed to offload read traffic from the primary instance. The application can be configured to send read-only queries to the replica endpoint. Connection pooling with PgBouncer helps with connection management but does not offload reads. Query optimization reduces load but doesn't scale reads. Read replicas are the standard solution.
What should I do if I get this PCDE question wrong?
Identify which PCDE 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: "primary". Asks for the main purpose or function, not a secondary benefit. Eliminate answers that describe side-effects or partial functions.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
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Last reviewed: Jul 4, 2026
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.
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