Streaming Algorithms — One Pass, Bounded Memory

Why it matters

Streaming is standard for big data. Understanding shapes analytics.

The architecture

Single pass.

Sub-linear memory (polylog).

Approximation guarantees.

How it works end to end

Frequent items: heavy hitters via Count-Min Sketch.

Distinct count: HyperLogLog.

Quantiles: t-digest, GK-summary.

Sliding window variants: exponential histograms.