The answer is adding indexes on frequently queried columns and increasing the database tier machine type. Adding indexes reduces high read latency by eliminating costly full table scans, allowing PostgreSQL to locate rows directly through index lookups rather than scanning every page. Increasing the machine tier provides additional CPU and memory, which accelerates query processing and buffer cache efficiency, directly tackling the root cause of slow reads. On the Google Professional Cloud Database Engineer exam, this question tests your ability to distinguish between scaling compute resources and optimizing query structure—a common trap is confusing read replicas or connection pooling with latency reduction, but replicas distribute load without speeding up individual queries, and pooling only manages connections. Remember the memory tip: “Index the path, scale the machine” to pair query optimization with hardware upgrades for read latency fixes.
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.
Which TWO actions would help optimize a Cloud SQL for PostgreSQL database experiencing high read latency?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Add indexes on frequently queried columns
Adding indexes on frequently queried columns (B) reduces full table scans, and increasing the database tier machine type (D) provides more CPU/memory for query processing. Read replicas (A) distribute load but do not reduce individual query latency; connection pooling (C) helps connection management, not read latency; automatic storage increase (E) is irrelevant.
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.
✗
Increase the number of read replicas
Why it's wrong here
Read replicas help distribute read load but do not reduce latency for individual queries.
✓
Add indexes on frequently queried columns
Why this is correct
Indexes speed up data retrieval by reducing full table scans.
Related concept
Read the scenario before looking for a memorised answer.
✓
Increase database tier machine type
Why this is correct
A larger machine type provides more resources (CPU, memory) that can improve query performance.
Related concept
Read the scenario before looking for a memorised answer.
✗
Configure automatic storage increase
Why it's wrong here
Auto-storage increase does not affect read latency; it only ensures disk space is available.
✗
Use pgBouncer connection pooling
Why it's wrong here
Connection pooling manages connections, not read query latency.
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 media company stores terabytes of video archives that are accessed once a year for audit purposes. Moving these objects to a cold storage tier (Azure Archive, S3 Glacier, or Google Nearline) costs a fraction of hot storage. Questions like this test whether you understand storage tiers, access frequency tradeoffs, and retrieval latency requirements.
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.
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 indexes on frequently queried columns — Adding indexes on frequently queried columns (B) reduces full table scans, and increasing the database tier machine type (D) provides more CPU/memory for query processing. Read replicas (A) distribute load but do not reduce individual query latency; connection pooling (C) helps connection management, not read latency; automatic storage increase (E) is irrelevant.
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.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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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
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