Professional Data EngineerDesigning data processing systemsHard

A global e-commerce company needs to store product catalog data, which is frequently updated and accessed with low latency by customer-facing applications worldwide. The data model is semi-structured and requires flexible schema management. The solution must provide strong consistency and high availability across multiple regions. Which Google Cloud service should the company use?

  1. ABigQuery.
  2. BCloud Firestore.
  3. CCloud Spanner.
  4. DCloud SQL.
Show answer & explanation

Correct answer: C. Cloud Spanner.

Cloud Spanner is a globally distributed, strongly consistent, and highly available relational database service that offers unlimited scale. Its ability to provide strong consistency and low-latency access across multiple regions, combined with a flexible schema for semi-structured data (via JSON columns or flexible table designs), makes it ideal for a global product catalog with frequent updates.

Why the other options are wrong

  • A. BigQuery is a data warehouse for analytics, not an operational database for low-latency, transactional access from customer-facing applications.
  • B. Cloud Firestore is a NoSQL document database suitable for mobile, web, and server development, offering good scalability and flexibility but typically for smaller-scale global consistency needs compared to Spanner's full relational capabilities and global consistency guarantees.
  • D. Cloud SQL is a regional relational database service, not designed for global, multi-regional strong consistency and low-latency access required by a global e-commerce platform at this scale.

Global Relational Database

A globally distributed, strongly consistent, and highly available relational database with unlimited scale, suitable for critical operational workloads.

  • Offers strong consistency across regions.
  • Provides high availability and unlimited scalability.
  • Supports SQL queries and relational schemas.

Memory trick: Spanner: Spanning the globe with Strong, Scalable, Speedy data.

More Designing data processing systems questions