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Windowing
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Cheatsheet: Windowing

Recommended reading: 4 mins

Core Description

Group unbounded streaming data into logical time intervals.

beam.WindowInto()
returns: PCollection
Purpose

Binds PCollection elements into time-based logical windows.

Syntax Signaturebeam.WindowInto(windowfn, *args, **kwargs)
Usage Example
import apache_beam as beam
from apache_beam.transforms.window import FixedWindows

# Group records into 60-second fixed intervals
windowed = stream | beam.WindowInto(FixedWindows(60))
Used In

Aggregating metrics in real-time streaming pipelines.

Related Methods

FixedWindows(), SlidingWindows(), Sessions()

Remember:

Windowing divides unbounded streams into bounded slices, which is mandatory before using Combine or GroupByKey.

Windowing Types Comparison

Review typical real-world properties of temporal window structures.

Window TypeOverlappingAlignmentUse Case
Fixed WindowsNoAligned globallyHourly/daily summaries
Sliding WindowsYesAligned globally10-minute moving average every 1 minute
Session WindowsNoUnaligned (per-key)User behavior tracking (idle timeout)
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