Tag
mergeability
- Jul 21, 2026 Counting Distinct Elements with HyperLogLog Registers How a fixed array of small registers estimates cardinality to within about one percent, why the estimator uses a harmonic mean, and how register-wise maximum makes sketches mergeable. algorithms
- May 4, 2024 Exponential Histograms and the Mergeable Bucket Layout How boundaries derived from a growth factor give uniform relative error, why an offset and a scale factor are enough to merge two histograms, and where the resolution limits sit. observability
- Jul 20, 2023 The Streaming Model: One Pass, Sublinear Space, Approximate Answers What the one-pass model forbids, how cash-register and turnstile streams differ, and why exact answers cost linear space while sketches can be merged by addition. algorithms
- Aug 17, 2022 Aggregating Percentiles Across a Fleet Without Losing the Tail Why per-host percentiles cannot be combined directly, how cumulative bucketed histograms make merging exact, and what temporal aggregation does to the tail that spatial aggregation does not. performance engineering