Tag
event-time
- May 21, 2026 Window Assignment and Trigger Semantics How an event is mapped to windows, why sliding windows multiply state, and how triggers separate when a result is emitted from what it contains. data engineering
- Jan 13, 2026 Watermarks as Completeness Signals How a watermark asserts that no earlier event will arrive, how it is propagated through operators, and what happens when the assertion is wrong. data engineering
- Oct 2, 2025 Measuring Disorder to Size a Lateness Budget How to derive the watermark delay and allowed lateness from the arrival-delay distribution, and why a percentile is the only honest input to that choice. data engineering
- Oct 15, 2024 Interval Joins Over Event Time Why a stream-stream join must buffer both sides, how the watermark of the slower input gates the match, and where the retained state actually goes. data engineering
- Oct 3, 2024 Sliding Windows and Exponential Histograms for Recent Data Why a window over the last W items needs a different summary from a whole-stream sketch, how bucket merging bounds error to a constant factor, and what late-arriving data does to the guarantee. algorithms
- Aug 14, 2023 Measuring Freshness From Event Time, Not Arrival Time A table can be loaded on schedule and still be stale: lag is a distribution over records, and comparing the newest row timestamp to the clock hides the tail. data engineering
- May 4, 2022 Event Time and Processing Time in a Stream Operator Why the clock an operator reads decides whether a replay reproduces its output, and how the two clocks diverge when a source falls behind. data engineering