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A financial services company is building a data lake on Google Cloud. They need to store raw, semi-structured transaction data (e.g., JSON, CSV) from various sources, including on-premises databases and third-party APIs. The data volume is expected to grow to petabytes, and it will be accessed by different analytical tools (BigQuery, Spark) for ad-hoc queries and machine learning models. The solution must be highly durable, globally accessible, and cost-effective for long-term storage, with flexible schema support. Which Google Cloud storage service is most appropriate for their data lake's raw data storage layer?

  1. ABigtable
  2. BCloud Spanner
  3. CCloud SQL
  4. DCloud Storage
Show answer & explanation

Correct answer: D. Cloud Storage

Cloud Storage is the ideal choice for a data lake's raw data storage layer. It offers petabyte-scale capacity, high durability, global accessibility, and cost-effectiveness. Its object-based nature makes it schema-agnostic, supporting various file formats (JSON, CSV) and allowing seamless integration with analytical tools like BigQuery (via external tables) and Spark (via Cloud Dataproc).

Why the other options are wrong

  • A. Bigtable is a NoSQL wide-column database, optimized for high-throughput, low-latency reads/writes, but not typically the primary raw storage layer for a data lake with ad-hoc query needs.
  • B. Cloud Spanner is a globally distributed relational database, designed for transactional workloads, not for raw, schema-flexible data lake storage.
  • C. Cloud SQL is a regional relational database, unsuitable for petabyte-scale, schema-flexible data lake storage.

Cloud Storage for Data Lakes

Cloud Storage serves as a foundational component for data lakes on Google Cloud, providing scalable, durable, and cost-effective object storage for raw and semi-structured data.

  • Schema-agnostic, supports all file types
  • Integrates with BigQuery, Dataflow, Dataproc
  • Offers different storage classes for cost optimization

Memory trick: Cloud Storage is the vast, flexible lake for your raw data.

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