Does HyperLogLog work well with merging data from multiple servers?
Yes—one of its biggest advantages. Merge two HyperLogLog instances by taking the element-wise maximum of their registers. This enables exact-level accuracy while counting globally across a distributed cluster.
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Count Billions in 12 KilobytesHyperLogLog estimates cardinality by reading leading zeros in hashed values, trading 1% error for fixed memory.
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