- A
Cloud Bigtable
Why wrong: Bigtable is a wide-column NoSQL database for analytical workloads, not mobile apps with offline sync.
- B
Firestore
Firestore is a serverless NoSQL document database with offline support, real-time listeners, and security rules, ideal for mobile apps.
- C
Cloud SQL
Why wrong: Cloud SQL is a managed relational database; it does not offer offline sync or serverless scaling.
- D
Cloud Spanner
Why wrong: Spanner is a globally distributed relational database; it is not serverless and does not support client-side offline sync.
Question 368 of 999
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. 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.
A mobile application developer needs a serverless NoSQL database that supports offline data synchronization across devices and real-time updates. Which Google Cloud database service should they 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
✓
Firestore
Firestore is a serverless, NoSQL document database that provides built-in offline data synchronization across devices and real-time updates via snapshot listeners. It automatically handles conflict resolution and data replication, making it ideal for mobile applications that need to work offline and sync when connectivity is restored.
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.
- ✗
Cloud Bigtable
Why it's wrong here
Bigtable is a wide-column NoSQL database for analytical workloads, not mobile apps with offline sync.
- ✓
Firestore
Why this is correct
Firestore is a serverless NoSQL document database with offline support, real-time listeners, and security rules, ideal for mobile apps.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Cloud SQL
Why it's wrong here
Cloud SQL is a managed relational database; it does not offer offline sync or serverless scaling.
- ✗
Cloud Spanner
Why it's wrong here
Spanner is a globally distributed relational database; it is not serverless and does not support client-side offline sync.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The exam often tests the distinction between NoSQL databases optimized for real-time mobile sync (Firestore) versus those designed for high-throughput analytics (Bigtable) or global relational consistency (Spanner), leading candidates to choose a scalable but inappropriate service.
Detailed technical explanation
How to think about this question
Firestore uses a multi-region replication model and supports real-time listeners via gRPC streaming, which push changes to clients as they occur. Its offline persistence layer uses a local SQLite cache to store pending writes, which are automatically synchronized with the server using a last-write-wins conflict resolution strategy. This architecture is critical for mobile apps like collaborative editing or chat, where users expect instant updates and seamless offline-to-online transitions.
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
A cloud solutions architect for a retail company is evaluating services for a new workload. The correct answer here reflects best practice for the specific scenario described — not a general cloud recommendation. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Cloud exam questions reward reading the constraint carefully: the same technology can be right or wrong depending on the use case.
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 |
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.
- →
Design Scalable and Highly Available Cloud Database Solutions — study guide chapter
Learn the concepts, then practise the questions
- →
Design Scalable and Highly Available Cloud Database Solutions practice questions
Targeted practice on this topic area only
- →
All PCD questions
999 questions across all exam domains
- →
Google Professional Cloud Developer study guide
Full concept coverage aligned to exam objectives
- →
PCD practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related PCD practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Manage a Solution that Can Span Multiple Database Systems practice questions
Practise PCD questions linked to Manage a Solution that Can Span Multiple Database Systems.
Deploy Scalable and Highly Available Databases in Google Cloud practice questions
Practise PCD questions linked to Deploy Scalable and Highly Available Databases in Google Cloud.
Design Scalable and Highly Available Cloud Database Solutions practice questions
Practise PCD questions linked to Design Scalable and Highly Available Cloud Database Solutions.
Migrate Data Solutions practice questions
Practise PCD questions linked to Migrate Data Solutions.
Designing highly scalable, available, and reliable cloud-native applications practice questions
Practise PCD questions linked to Designing highly scalable, available, and reliable cloud-native applications.
Building and testing applications practice questions
Practise PCD questions linked to Building and testing applications.
Deploying applications practice questions
Practise PCD questions linked to Deploying applications.
Integrating Google Cloud services practice questions
Practise PCD questions linked to Integrating Google Cloud services.
Managing application performance monitoring practice questions
Practise PCD questions linked to Managing application performance monitoring.
PCD fundamentals practice questions
Practise PCD questions linked to PCD fundamentals.
PCD scenario practice questions
Practise PCD questions linked to PCD scenario.
PCD troubleshooting practice questions
Practise PCD questions linked to PCD troubleshooting.
Practice this exam
Start a free PCD practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
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: Firestore — Firestore is a serverless, NoSQL document database that provides built-in offline data synchronization across devices and real-time updates via snapshot listeners. It automatically handles conflict resolution and data replication, making it ideal for mobile applications that need to work offline and sync when connectivity is restored.
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 →
Keep practising
More PCD practice questions
- A company is deploying a microservices architecture on GKE. They need to expose a set of related microservices under a s…
- You need to monitor the CPU usage of a Compute Engine instance and trigger an alert when it exceeds 80% for 5 minutes. W…
- A Cloud Bigtable instance has a single cluster. To improve availability and read throughput, the team decides to add a s…
- A developer wants to enable IAM database authentication for Cloud SQL for PostgreSQL. Which IAM role must be granted to…
- A company is using Cloud Bigtable for a time-series workload. They want to monitor performance and identify hot spots. W…
- A company wants to run hybrid transactional/analytical processing (HTAP) workloads on a PostgreSQL-compatible database w…
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.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.