- A
Cloud Bigtable
Why wrong: Bigtable is a wide-column database, not a document database.
- B
BigQuery
Why wrong: BigQuery is an analytics data warehouse, not suited for transactional user profile storage.
- C
Cloud Spanner
Why wrong: Spanner is relational with fixed schema, not a document database.
- D
Cloud Firestore
Firestore stores JSON documents, ideal for flexible schema mobile apps.
Question 497 of 1,000
PDE Storing the Data Practice Question
This PDE practice question tests your understanding of storing the data. 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.
An application needs to store user profile data in a document database with flexible schema. The data is accessed frequently from a mobile app. Which Google Cloud database is BEST suited?
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
Cloud Firestore is a NoSQL document database designed for mobile and web app development, offering flexible schema, real-time data synchronization, and automatic scaling. It directly supports frequent reads from mobile apps through its client SDKs and offline persistence, making it the best fit for storing user profile data with varying attributes.
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 database, not a document database.
- ✗
BigQuery
Why it's wrong here
BigQuery is an analytics data warehouse, not suited for transactional user profile storage.
- ✗
Cloud Spanner
Why it's wrong here
Spanner is relational with fixed schema, not a document database.
- ✓
Cloud Firestore
Why this is correct
Firestore stores JSON documents, ideal for flexible schema mobile apps.
Related concept
Read the scenario before looking for a memorised answer.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse Cloud Firestore with Cloud Bigtable because both are NoSQL, but Bigtable lacks document flexibility, real-time sync, and mobile SDK support, which are essential for the described use case.
Detailed technical explanation
How to think about this question
Firestore stores data in documents (key-value pairs) organized into collections, supporting subcollections and real-time listeners via WebSocket connections. Its offline persistence uses a local SQLite cache, enabling reads even without network connectivity, which is critical for mobile apps. The database automatically indexes all fields by default, but composite indexes must be created manually for complex queries, a subtle behavior that can impact query performance if overlooked.
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 company's IT admin needs to give a contractor read-only access to production logs without sharing account credentials. Using role-based access control (RBAC) and temporary scoped permissions — not a permanent shared password — is the correct pattern. Questions like this test whether you can apply least-privilege access across cloud identity services.
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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Storing the Data — study guide chapter
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Storing the Data practice questions
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FAQ
Questions learners often ask
What does this PDE question test?
Storing the Data — This question tests Storing the Data — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Cloud Firestore — Cloud Firestore is a NoSQL document database designed for mobile and web app development, offering flexible schema, real-time data synchronization, and automatic scaling. It directly supports frequent reads from mobile apps through its client SDKs and offline persistence, making it the best fit for storing user profile data with varying attributes.
What should I do if I get this PDE 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.
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Last reviewed: Jul 4, 2026
This PDE 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 PDE exam.
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