Professional Data Engineer

Build and operate the data processing systems behind analytics and ML on Google Cloud, including BigQuery, Dataflow, and Pub/Sub, and track your readiness for the Professional Data Engineer exam.

Advanced

Prepare and test your skills

Advanced

Prepare and test your skills

Concept

exactly-once processing

Topic in 2 exam domains

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Also called: exactly once

A stream processing guarantee ensuring each data record is processed exactly one time without duplicates or data loss.

Where this appears on the exam

2 subdomains in 2 of 5 domains

Domain 2
Ingesting and processing the data
~25% of exam
1. 2.2Building the pipelines
  - Streaming (e.g., windowing, late arriving data)
Domain 5
Maintaining and automating data workloads
~18% of exam
1. 5.5Maintaining awareness of failures and mitigating impact
  - Designing system for fault tolerance and managing restarts

How learners score on this topic

Last updated October 23, 2026

Professional Data Engineer

Build and operate the data processing systems behind analytics and ML on Google Cloud, including BigQuery, Dataflow, and Pub/Sub, and track your readiness for the Professional Data Engineer exam.

Advanced

Prepare and test your skills

Advanced

Prepare and test your skills

Concept

exactly-once processing

Topic in 2 exam domains

X LinkedIn Facebook Reddit

Also called: exactly once

A stream processing guarantee ensuring each data record is processed exactly one time without duplicates or data loss.

Where this appears on the exam

2 subdomains in 2 of 5 domains

Domain 2
Ingesting and processing the data
~25% of exam
1. 2.2Building the pipelines
  - Streaming (e.g., windowing, late arriving data)
Domain 5
Maintaining and automating data workloads
~18% of exam
1. 5.5Maintaining awareness of failures and mitigating impact
  - Designing system for fault tolerance and managing restarts

How learners score on this topic

Last updated October 23, 2026