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Count-min Sketch to Infinity

Talkat NDC Oslo 2022 · 2022-09-26..09-30· [databases, python]
slides:none on file

Implements Bloom Filter, Count‑Min Sketch, HyperLogLog and Heavy Keeper using Redis/RedisBloom/RediStack and .NET, and measures them against Postgres and naive Redis sets. Demo parses Moby Dick words: probabilistic structures insert in about 700 ms versus 3–5s for Postgres, use two orders of magnitude smaller memory (kilobytes vs megabytes), Count‑Min Sketch never undercounts but overcounts ≈2%, HyperLogLog undercounts ≈1%, deletes are unsupported; commands shown include BF.RESERVE, CMS.INCRBY, TOPK and PF (HyperLogLog) ops.

AI-written summary · about

  1. 0:00Introduction
  2. 2:08What is a probabilistic data structure
  3. 5:22History in Redis
  4. 8:52Set membership with Bloom filters
  5. 22:32Counting with Count-Min Sketch
  6. 32:29Cardinality with HyperLogLog
  7. 40:58Heavy hitters with Heavy Keeper
  8. 48:00Demo comparison
  9. 56:30Resources and closing
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