tdigest_merge()tdigest_merge()

合并 tdigest 结果(聚合版 tdigest_merge() 的标量版本)。Merges tdigest results (scalar version of the aggregate version tdigest_merge()).

此处详细了解基础算法 (T-Digest) 和预估误差。Read more about the underlying algorithm (T-Digest) and the estimated error here.

语法Syntax

merge_tdigests( Expr1, Expr2, ...)merge_tdigests( Expr1, Expr2, ...)

tdigest_merge( Expr1, Expr2, ...) - 别名。tdigest_merge( Expr1, Expr2, ...) - An alias.

参数Arguments

  • 列,包含要合并的 tdigest 值。Columns that have the tdigest values to be merged.

返回Returns

将列 *Expr1**Expr2*、... *ExprN* 合并为一个 tdigest 后的结果。The result for merging the columns *Expr1*, *Expr2*, ... *ExprN* to one tdigest.

示例Examples

range x from 1 to 10 step 1 
| extend y = x + 10
| summarize tdigestX = tdigest(x), tdigestY = tdigest(y)
| project merged = tdigest_merge(tdigestX, tdigestY)
| project percentile_tdigest(merged, 100, typeof(long))
percentile_tdigest_mergedpercentile_tdigest_merged
2020