pyspark.sql.functions.approx_count_distinct¶
-
pyspark.sql.functions.
approx_count_distinct
(col, rsd=None)[source]¶ Aggregate function: returns a new
Column
for approximate distinct count of column col.New in version 2.1.0.
- Parameters
- col
Column
or str - rsdfloat, optional
maximum relative standard deviation allowed (default = 0.05). For rsd < 0.01, it is more efficient to use
count_distinct()
- col
Examples
>>> df.agg(approx_count_distinct(df.age).alias('distinct_ages')).collect() [Row(distinct_ages=2)]