dcount_hll()dcount_hll()

根据 hll 结果(已由 hllhll_merge 生成)计算 dcount。Calculates the dcount from hll results (that were generated by hll or hll_merge).

阅读基础算法 (HyperLogLog ) 和估算准确度Read about the underlying algorithm (HyperLogLog) and estimation accuracy.

语法Syntax

dcount_hll(Expr)dcount_hll(Expr)

参数Arguments

返回Returns

Expr 中每个值的非重复计数The distinct count of each value in Expr

示例Examples

StormEvents
| summarize hllRes = hll(DamageProperty) by bin(StartTime,10m)
| summarize hllMerged = hll_merge(hllRes)
| project dcount_hll(hllMerged)
dcount_hll_hllMergeddcount_hll_hllMerged
315315