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17. Stream DeduplicationMedium

Core Transformations⏱️ ~10 mins

17. Stream Deduplication

Enterprise Architecture Context

In production stream-processing architectures (Google Cloud Dataflow / Flink), pipeline stages must handle parallel transformations without data loss, managing schema mutations and aggregations across distributed worker workers.

Problem Statement

### Business Context Clickstream events often produce duplicates due to network retries from mobile clients. Pipelines deduplicate events before downstream ingestion. ### Problem Statement Write a function `distinct_elements(input_pcoll)` that eliminates duplicate elements across a PCollection using `beam.Distinct()`.

Key Learning Objectives

  • Understand distributed Apache Beam execution DAG stages and pipeline lifecycle.
  • Apply idiomatic functional Python transforms using the pipe operator |.
  • Ensure data consistency and idempotency across distributed stream workers.

Sample Data Fixtures

Sample Example 1
Input Stream:
[1, 1, 2, 2, 3]
Expected Output:
[1, 2, 3]
Sample Example 2
Input Stream:
['A', 'A', 'B']
Expected Output:
['A', 'B']
Topics:#Distinct#Fundamentals
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