DS_HLL_COMBINE (Lakehouse v2)

将多个 DataSketches HLL 草图合并为单个草图。

Analyze 语法

func.ds_hll_combine(get_column(table, 'hll_sketch'))

Analyze 示例

func.ds_hll_combine(get_column(table, 'hll_sketch'))

┌───────────────────┐
│ (combined sketch) │
└───────────────────┘

SQL 语法

DS_HLL_COMBINE(<sketch_column>)

SQL 示例

SELECT DS_HLL_ESTIMATE(DS_HLL_COMBINE(sketch_col)) FROM daily_sketches;

┌───────┐
│ 25000 │
└───────┘