- A
AlloyDB with HA configuration
Why wrong: AlloyDB HA is also synchronous, but for a 200 GB OLTP migration from PostgreSQL, Cloud SQL is more straightforward and cost-effective.
- B
Cloud SQL HA instance
Correct: synchronous replication to standby in different zone, automatic failover, zero RPO.
- C
Cloud SQL single zone instance with an external replica
Why wrong: External replica is asynchronous, not zero RPO.
- D
Cloud SQL instance with cross-region read replica
Why wrong: Cross-region replicas are asynchronous, not zero RPO.
Question 716 of 980
PCD Practice Question: Design Scalable and Highly Available Cloud Database Solutions
This PCD practice question tests your understanding of design scalable and highly available cloud database solutions. 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.
You are migrating an on-premises PostgreSQL database (OLTP, 200 GB) to Google Cloud. The database requires high availability with automatic failover and zero RPO. Which configuration should you use?
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
✓
Cloud SQL HA instance
Cloud SQL HA instance provides synchronous replication to a standby in a different zone within the same region, ensuring automatic failover with zero RPO because no committed transaction is lost. This meets the requirement for high availability and zero data loss for an OLTP PostgreSQL database of this size.
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.
- ✗
AlloyDB with HA configuration
Why it's wrong here
AlloyDB HA is also synchronous, but for a 200 GB OLTP migration from PostgreSQL, Cloud SQL is more straightforward and cost-effective.
- ✓
Cloud SQL HA instance
Why this is correct
Correct: synchronous replication to standby in different zone, automatic failover, zero RPO.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Cloud SQL single zone instance with an external replica
Why it's wrong here
External replica is asynchronous, not zero RPO.
- ✗
Cloud SQL instance with cross-region read replica
Why it's wrong here
Cross-region replicas are asynchronous, not zero RPO.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates confuse high availability (HA) with disaster recovery (DR) or assume that any replica (like a cross-region read replica) can provide automatic failover with zero RPO, but only synchronous replication within the same region achieves that guarantee.
Detailed technical explanation
How to think about this question
Cloud SQL HA uses synchronous replication to a standby in a different zone, leveraging PostgreSQL's synchronous replication feature with a specific replication slot to ensure every transaction is committed on both the primary and standby before acknowledging the client. This guarantees zero RPO because no data is lost even if the primary zone fails, and automatic failover occurs within seconds. In a real-world scenario, this is critical for OLTP systems where even a single transaction loss can cause financial or data integrity issues.
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
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 exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
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FAQ
Questions learners often ask
What does this PCD question test?
Design Scalable and Highly Available Cloud Database Solutions — This question tests Design Scalable and Highly Available Cloud Database Solutions — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Cloud SQL HA instance — Cloud SQL HA instance provides synchronous replication to a standby in a different zone within the same region, ensuring automatic failover with zero RPO because no committed transaction is lost. This meets the requirement for high availability and zero data loss for an OLTP PostgreSQL database of this size.
What should I do if I get this PCD 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 →
Last reviewed: Jul 4, 2026
This PCD 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 PCD exam.
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