easyMultiple ChoiceObjective-mapped
Google PCA Practice Question: A startup is building a mobile app backend that…
A startup is building a mobile app backend that requires real-time data synchronization across multiple users. They need a fully managed, serverless NoSQL database that scales automatically and supports offline persistence. Which database should they choose?
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 Firestore
Firestore is a serverless NoSQL document database designed for mobile apps with real-time sync, offline support, and automatic scaling. Cloud Bigtable is for high-throughput time-series data, not mobile. Cloud SQL is relational and not serverless. Cloud Spanner is globally distributed relational, overkill for a mobile app backend.
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 Spanner
Why it's wrong here
Spanner is a globally distributed relational database, overkill and expensive for a typical mobile backend.
- ✗
Cloud Bigtable
Why it's wrong here
Bigtable is a wide-column NoSQL for time-series and high-throughput workloads, not designed for mobile real-time sync.
- ✗
Cloud SQL
Why it's wrong here
Cloud SQL is a relational database, not serverless, and lacks built-in real-time sync.
- ✓
Cloud Firestore
Why this is correct
Firestore provides real-time updates, offline persistence, and automatic scaling, making it ideal for mobile app backends.
Visual reference
Quick reference
Cloud Service Model Comparison
| Model | You Manage | Provider Manages | Examples |
|---|---|---|---|
| IaaS | OS, runtime, apps, data | Hardware, hypervisor, networking | EC2, Azure VMs, GCP Compute Engine |
| PaaS | Apps and data | OS, runtime, middleware, hardware | Elastic Beanstalk, Azure App Service |
| SaaS | Data and settings only | Everything else | Microsoft 365, Salesforce, Workday |
| FaaS / Serverless | Function code only | Infra, scaling, runtime | Lambda, Azure Functions, Cloud Run |
| CaaS | Containers and apps | Kubernetes, OS, hardware | EKS, AKS, GKE |
Go deeper
Related to this question
Learn chapter
Introduction to Google Cloud Platform
Key term
Cloud SQL
Cloud SQL is a fully managed relational database service that lets you set up, maintain, and scale SQL databases (like MySQL, PostgreSQL, and SQL Server) in the cloud without managing the underlying infrastructure.
Key term
Cloud Spanner
Cloud Spanner is a fully managed, globally distributed relational database service from Google Cloud that combines the benefits of relational database structure with horizontal scalability and strong consistency.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.