tdigest_merge()(聚合函数)tdigest_merge() (aggregation function)
将 tdigest 结果合并到组中。Merges tdigest results across the group.
在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
summarize tdigest_merge(
Expr)
。summarize tdigest_merge(
Expr)
.
summarize tdigest_merge(
Expr)
- 别名。summarize tdigest_merge(
Expr)
- An alias.
参数Arguments
- Expr:用于聚合计算的表达式。Expr : Expression that will be used for aggregation calculation.
返回Returns
组中 Expr 的合并 tdigest 值。The merged tdigest values of Expr across the group.
提示Tips
可以使用函数 [
percentile_tdigest()
] (percentile-tdigestfunction.md)。You may use the function [percentile_tdigest()
] (percentile-tdigestfunction.md).同一组中包含的所有 tdigest 必须属于同一类型。All tdigests that are included in the same group must be of the same type.