ApproxPercentileReduce version 1.8, ApproxPercentileMap version 1.6
SELECT * FROM ApproxPercentileReduce ( ON ([ SELECT * FROM ] ApproxPercentileMap ( ON { table | view | (query) } USING TargetColumns ('target_column' [,...]) [ ErrorRate (error) ] [ GroupByColumns ('group_column' [,...]) ] ) AS alias_1 ) PARTITION BY [ 1 | group_column [,...]] USING [ Percentile (percentile [,...]) ] [ TargetColumns ('target_column' [,...]) ] [ GroupByColumns ('group_column' [,...]) ] ) AS alias_2;