Google PCA Design and plan a cloud solution architecture Practice Question
A global e-commerce company is designing its application architecture on Google Cloud. The application must serve users from multiple regions with low latency and must be able to fail over between regions automatically in case of a regional outage. The company wants to minimize operational overhead and ensure that the database layer supports multi-region writes with strong consistency. Which database solution should they choose?
⚠ Common exam trap
The trap here is assuming that cross-region read replicas or NoSQL databases can handle multi-region writes with strong consistency, when they typically offer read-only replicas or eventual consistency.
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 Spanner with a multi-region configuration.
Cloud Spanner is the only Google Cloud database that offers multi-region writes with strong consistency and automatic failover. It is designed for global applications requiring low latency and high availability. The other options either do not support multi-region writes or do not provide strong consistency across regions.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Cloud SQL for PostgreSQL with cross-region read replicas.
Why it's wrong here
Cloud SQL supports read replicas in other regions, but these replicas are read-only and cannot accept writes. Failover to a replica requires manual promotion or configuration, and it does not support multi-region writes. This does not meet the requirement for multi-region writes with strong consistency.
- ✗
Cloud Bigtable with a multi-region cluster.
Why it's wrong here
Cloud Bigtable is a NoSQL database that provides high throughput and low latency, but it does not support strong consistency across regions. It offers eventual consistency for multi-region configurations, which does not meet the requirement for strong consistency.
- ✓
Cloud Spanner with a multi-region configuration.
Why this is correct
Cloud Spanner is a globally distributed, horizontally scalable database that supports multi-region configurations with strong consistency. It provides automatic failover and low-latency reads and writes across regions. This meets the requirements for multi-region writes, strong consistency, and minimal operational overhead.
- ✗
Firestore in Datastore mode with multi-region replication.
Why it's wrong here
Firestore in Datastore mode provides multi-region replication and strong consistency for reads, but it is a NoSQL database and does not support multi-region writes with strong consistency in the same way as Spanner. It is designed for eventual consistency in some operations and may not meet the requirement for a relational-like workload with multi-region writes.
Go deeper
Related to this question
Learn chapter
Google Cloud Compute Options Overview
Key term
Latency
Latency is the time delay between a request being sent over a network and the response being received, often measured in milliseconds.
Key term
High availability
High availability is a system design approach that aims to keep applications and services operational and accessible with minimal downtime, even when some components fail.
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Google Cloud exam blueprint
This PCA 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 PCA exam.