- A
Firestore
Why wrong: Firestore is a document database that supports transactions but is not relational and best for mobile/web apps.
- B
Cloud Bigtable
Why wrong: Bigtable is a NoSQL database that does not support ACID transactions across rows.
- C
Cloud SQL
Cloud SQL provides ACID compliance, high availability, and PITR for moderate OLTP workloads.
- D
Cloud Spanner
Why wrong: Spanner is globally distributed and designed for higher throughput, but is more complex and costly than needed for a few thousand tps.
Question 225 of 1,000
PDE Storing the Data Practice Question
This PDE practice question tests your understanding of storing the data. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. 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 data engineer needs to store transactional data for an e-commerce application that requires ACID compliance, automatic failover, and point-in-time recovery. The expected throughput is a few thousand transactions per second. Which Google Cloud storage option 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 full ACID compliance, automated failover with high availability configurations, and point-in-time recovery via binary log replay. It supports up to several thousand transactions per second with appropriate machine sizing, making it suitable for this e-commerce workload.
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.
- ✗
Firestore
Why it's wrong here
Firestore is a document database that supports transactions but is not relational and best for mobile/web apps.
- ✗
Cloud Bigtable
Why it's wrong here
Bigtable is a NoSQL database that does not support ACID transactions across rows.
- ✓
Cloud SQL
Why this is correct
Cloud SQL provides ACID compliance, high availability, and PITR for moderate OLTP workloads.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Cloud Spanner
Why it's wrong here
Spanner is globally distributed and designed for higher throughput, but is more complex and costly than needed for a few thousand tps.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often choose Cloud Spanner for any ACID requirement, overlooking that Cloud SQL is the cost-effective and simpler choice for single-region transactional workloads with moderate throughput.
Detailed technical explanation
How to think about this question
Cloud SQL uses MySQL or PostgreSQL engines, which implement ACID through row-level locking, undo logs, and write-ahead logging (WAL). Point-in-time recovery is achieved by replaying binary logs (MySQL) or WAL archives (PostgreSQL) from a specific timestamp, allowing restoration to any second within the retention window. Automatic failover in a high-availability configuration relies on a standby instance in a different zone, using synchronous replication to ensure zero data loss.
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.
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
Learn the concepts, then practise the questions
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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 full ACID compliance, automated failover with high availability configurations, and point-in-time recovery via binary log replay. It supports up to several thousand transactions per second with appropriate machine sizing, making it suitable for this e-commerce workload.
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.
About these practice questions
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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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