PDE Ingesting and Processing the Data Practice Question
A financial services company receives real-time stock trade data via Pub/Sub. They need to enrich each trade with reference data from a Cloud SQL table and write the results to BigQuery for real-time analytics. The enrichment must handle late-arriving data and ensure exactly-once processing. Which Dataflow streaming pipeline configuration should be used?
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
✓
Build a custom Dataflow pipeline using the Storage Write API with exactly-once semantics and a side input from Cloud SQL
Using the Storage Write API with exactly-once semantics and side inputs to join with reference data provides the required enrichment and exactly-once guarantees.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Use a Dataflow Flex Template that reads from Pub/Sub, joins in memory, and writes to BigQuery using legacy streaming inserts
Why it's wrong here
Legacy streaming inserts may cause duplicates, and in-memory join may not handle late data well.
- ✗
Use Pub/Sub to BigQuery template with streaming inserts and a side input from Cloud SQL
Why it's wrong here
Streaming inserts do not guarantee exactly-once, and the template may not support custom enrichment.
- ✓
Build a custom Dataflow pipeline using the Storage Write API with exactly-once semantics and a side input from Cloud SQL
Why this is correct
Storage Write API with exactly-once ensures no duplicates, and side input allows enrichment from Cloud SQL.
- ✗
Deploy a Dataproc Spark Streaming job that reads from Pub/Sub, enriches via JDBC, and writes to BigQuery
Why it's wrong here
Spark Streaming can be used but is less integrated with BigQuery exactly-once features compared to Beam.
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Senior Network & Security Engineer · founder of Courseiva
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.