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A comment on Ask HN: What are some cool but obscure data structures you know about?. Parent comment

Re:Ask HN: What are some cool but obscure data structures yo... by tresil on Friday July 22, 2022 @02:43AM (#32189236)
Big fan of HLL

Apache foundation has a fantastic DataSketches library that includes HLL and many other powerful data analytics algorithms: https://datasketches.apache.org/

Lee Rhodes has done an excellent introduction to this library - explaining some of the use cases, advantages, and things to be aware of when using these techniques: https://www.youtube.com/watch?v=nO9pauS-mGQ

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Re:Ask HN: What are some cool but obscure data structures yo... by twic on Friday July 22, 2022 @05:23AM (#32190146)
On sketches, there is a genre of structure for estimating histogram-like statistics (median, 99th centile, etc) in fixed space, which i really like. Two examples:

t-digest https://github.com/tdunning/t-digest

DDSketch https://github.com/DataDog/sketches-java

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Re:Ask HN: What are some cool but obscure data structures yo... by arunk-s on Friday July 22, 2022 @08:59AM (#32191426)
In the same spirit there is also Circllhist from Circonus. https://arxiv.org/abs/2001.06561

There was a good discussion on approaches to store histogram here: https://news.ycombinator.com/item?id=31379383

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Re:Ask HN: What are some cool but obscure data structures yo... by ranman on Sunday July 24, 2022 @03:04PM (#32216550)
t-digest is used by AWS X-ray to render their charts
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