An online retailer has built their current application on Google App Engine. A new initiative at the company mandates that they extend their application to allow their customers to transact directly…

The correct answer is B. Cloud SQL. Cloud SQL is the right choice because it's a fully managed relational database service (supporting MySQL, PostgreSQL, and SQL Server) that handles both transactional workloads (OLTP) and integrates with BI tools like Looker and Data Studio for analytics - satisfying the "single…

Submitted by cyberguy42· Mar 30, 2026Designing data processing systems

Question

An online retailer has built their current application on Google App Engine. A new initiative at the company mandates that they extend their application to allow their customers to transact directly via the application. They need to manage their shopping transactions and analyze combined data from multiple datasets using a business intelligence (BI) tool. They want to use only a single database for this purpose. Which Google Cloud database should they choose?

Options

ABigQuery
BCloud SQL
CCloud BigTable
DCloud Datastore

How the community answered

(54 responses)

A
9% (5)
B
83% (45)
C
4% (2)
D
4% (2)

Explanation

Cloud SQL is the right choice because it's a fully managed relational database service (supporting MySQL, PostgreSQL, and SQL Server) that handles both transactional workloads (OLTP) and integrates with BI tools like Looker and Data Studio for analytics - satisfying the "single database" requirement for both use cases.

Why the distractors are wrong:

A. BigQuery is an analytics/data warehouse engine optimized for OLAP queries, not real-time transactional operations like shopping cart checkouts - it's read-heavy, not write-transactional.
C. Cloud Bigtable is a NoSQL wide-column store designed for massive-scale, low-latency workloads (IoT, time-series), not relational transactions or standard BI tool connectivity.
D. Cloud Datastore (now Firestore in Datastore mode) is a NoSQL document database suited for hierarchical/app data, but lacks the SQL interface and relational joins that BI tools rely on.

Memory tip: Think "SQL = transactions + BI" - whenever an exam question mentions needing both structured transactions and BI/reporting in one relational database on Google Cloud, Cloud SQL is almost always the answer. BigQuery is the trap because "analyze data" sounds like it fits, but it can't handle the transactional write side.

Topics

#Database selection#Cloud SQL#Transactional databases#Business intelligence

Community Discussion

No community discussion yet for this question.

Full PROFESSIONAL-DATA-ENGINEER Practice