Exam Professional Data Engineer topic 1 question 252 discussion

Actual exam question from Google's Professional Data Engineer

Question #: 252
Topic #: 1

[All Professional Data Engineer Questions]

You are designing a data warehouse in BigQuery to analyze sales data for a telecommunication service provider. You need to create a data model for customers, products, and subscriptions. All customers, products, and subscriptions can be updated monthly, but you must maintain a historical record of all data. You plan to use the visualization layer for current and historical reporting. You need to ensure that the data model is simple, easy-to-use, and cost-effective. What should you do?

A. Create a normalized model with tables for each entity. Use snapshots before updates to track historical data.
B. Create a normalized model with tables for each entity. Keep all input files in a Cloud Storage bucket to track historical data.
C. Create a denormalized model with nested and repeated fields. Update the table and use snapshots to track historical data.
D. Create a denormalized, append-only model with nested and repeated fields. Use the ingestion timestamp to track historical data.

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Suggested Answer: D 🗳️

by scaenruy at Jan. 3, 2024, 4:20 p.m.

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raaad

Highly Voted 11 months, 2 weeks ago

- A denormalized, append-only model simplifies query complexity by eliminating the need for joins. - Adding data with an ingestion timestamp allows for easy retrieval of both current and historical states. - Instead of updating records, new records are appended, which maintains historical information without the need to create separate snapshots.

upvoted 11 times

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