- A
Cloud Bigtable
Why wrong: No ACID transactions; designed for NoSQL time-series.
- B
Cloud SQL
Correct choice: ACID, backups, PITR, fits OLTP under 10k QPS.
- C
Firestore
Why wrong: No ACID across documents; suited for mobile/web apps.
- D
Cloud Spanner
Why wrong: Over-provisioned for the workload; higher cost and complexity.
Question 297 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.
A team needs to store transactional data for an e-commerce application that requires ACID transactions, automatic backups, and point-in-time recovery. The expected workload is under 10,000 QPS. 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 SQL
Cloud SQL is the correct choice because it provides fully managed relational databases (MySQL, PostgreSQL, SQL Server) with built-in ACID transaction support, automated backups, and point-in-time recovery (PITR) via binary logs or write-ahead logs. The workload of under 10,000 QPS is well within Cloud SQL's performance envelope, making it a cost-effective and operationally simple solution for transactional e-commerce data.
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
No ACID transactions; designed for NoSQL time-series.
- ✓
Cloud SQL
Why this is correct
Correct choice: ACID, backups, PITR, fits OLTP under 10k QPS.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Firestore
Why it's wrong here
No ACID across documents; suited for mobile/web apps.
- ✗
Cloud Spanner
Why it's wrong here
Over-provisioned for the workload; higher cost and complexity.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often choose Cloud Spanner for any workload requiring ACID transactions and high availability, overlooking that Cloud SQL is sufficient and more cost-effective for sub-10,000 QPS workloads, and that Cloud Spanner's global distribution and strong consistency come with a significant price premium.
Detailed technical explanation
How to think about this question
Cloud SQL's point-in-time recovery works by replaying binary logs (MySQL) or write-ahead logs (PostgreSQL) from a full backup to a specific timestamp, allowing recovery to within seconds of a failure. Under the hood, Cloud SQL uses regional persistent disks and synchronous replication to the zone for high availability, but it does not natively support cross-region replication without additional configuration. A real-world scenario where this matters is an e-commerce platform that needs to recover a single accidentally deleted product record from 30 minutes ago without restoring the entire database.
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 startup's cloud architect reviews their monthly bill and notices costs are higher than expected for a long-running batch job. Switching from on-demand instances to Reserved Instances — or using Spot/Preemptible VMs — can reduce compute costs by up to 72 %. Questions like this test whether you understand the tradeoffs between commitment, flexibility, and cost across cloud pricing models.
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.
- →
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 SQL — Cloud SQL is the correct choice because it provides fully managed relational databases (MySQL, PostgreSQL, SQL Server) with built-in ACID transaction support, automated backups, and point-in-time recovery (PITR) via binary logs or write-ahead logs. The workload of under 10,000 QPS is well within Cloud SQL's performance envelope, making it a cost-effective and operationally simple solution for transactional e-commerce data.
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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