- A
Cloud Spanner (transactions), Firestore (session storage), BigQuery (analytics)
Spanner provides ACID transactions at global scale, Firestore is great for session data, BigQuery for analytics.
- B
Cloud SQL (transactions), Firestore (session storage), Bigtable (analytics)
Why wrong: Bigtable is not a data warehouse; it's NoSQL for time-series.
- C
Firestore (transactions), Memorystore (session storage), BigQuery (analytics)
Why wrong: Firestore is not ideal for complex transactions; Memorystore is a cache, not persistent session storage.
- D
Cloud SQL (transactions), Bigtable (session storage), BigQuery (analytics)
Why wrong: Bigtable is optimised for time-series and key-value, not document/session storage.
Question 689 of 980
PCD Practice Question: Manage a Solution that Can Span Multiple Database Systems
This PCD practice question tests your understanding of manage a solution that can span multiple database systems. 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 company wants to implement polyglot persistence: an RDBMS for transactions, a NoSQL database for session storage, and a data warehouse for analytics. Which combination of Google Cloud databases best suits this architecture?
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 (transactions), Firestore (session storage), BigQuery (analytics)
Cloud Spanner provides ACID transactions with global consistency and horizontal scalability, making it ideal for transactional workloads. Firestore is a NoSQL document database optimized for real-time updates and high-read/write throughput, perfect for session storage. BigQuery is a serverless data warehouse designed for analytical queries on large datasets, fitting the analytics requirement.
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 Spanner (transactions), Firestore (session storage), BigQuery (analytics)
Why this is correct
Spanner provides ACID transactions at global scale, Firestore is great for session data, BigQuery for analytics.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Cloud SQL (transactions), Firestore (session storage), Bigtable (analytics)
Why it's wrong here
Bigtable is not a data warehouse; it's NoSQL for time-series.
- ✗
Firestore (transactions), Memorystore (session storage), BigQuery (analytics)
Why it's wrong here
Firestore is not ideal for complex transactions; Memorystore is a cache, not persistent session storage.
- ✗
Cloud SQL (transactions), Bigtable (session storage), BigQuery (analytics)
Why it's wrong here
Bigtable is optimised for time-series and key-value, not document/session storage.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Cisco often tests the misconception that Bigtable can serve as a data warehouse for analytics, but Bigtable is an operational database for low-latency access, not a SQL-based analytical warehouse like BigQuery.
Detailed technical explanation
How to think about this question
Polyglot persistence leverages the strengths of each database type: Cloud Spanner uses TrueTime and Paxos for global consistency and horizontal scaling, Firestore uses a real-time listener and automatic multi-region replication for session data, and BigQuery uses columnar storage and a distributed query engine for petabyte-scale analytics. A common real-world scenario is an e-commerce platform where Spanner handles order transactions, Firestore stores user sessions for fast login state, and BigQuery runs sales trend reports.
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 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.
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.
- →
Manage a Solution that Can Span Multiple Database Systems — study guide chapter
Learn the concepts, then practise the questions
- →
Manage a Solution that Can Span Multiple Database Systems practice questions
Targeted practice on this topic area only
- →
All PCD questions
980 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?
Manage a Solution that Can Span Multiple Database Systems — This question tests Manage a Solution that Can Span Multiple Database Systems — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Cloud Spanner (transactions), Firestore (session storage), BigQuery (analytics) — Cloud Spanner provides ACID transactions with global consistency and horizontal scalability, making it ideal for transactional workloads. Firestore is a NoSQL document database optimized for real-time updates and high-read/write throughput, perfect for session storage. BigQuery is a serverless data warehouse designed for analytical queries on large datasets, fitting the analytics requirement.
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.
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.