影响任务复杂性的相关要素是不同分组关键字的数量，而不是在计数函数中所看到的，不同的所聚合列的数量。

The relevant factor that impacts the complexity of the job is the number of different grouping keys, not the number of different aggregated columns that you would see in counting functions.

youdao

但是，如果使用具有相同分组关键字的多个聚合，或者对相同列进行计数的计数函数，其不会显著增加规则的执行时间。

But if you use multiple aggregations with the same grouping keys, or multiple counting functions that count the same column, it will not significantly increase the execution time of the rule.

youdao

如果利用相同的分组关键字或者没有分组关键字，来聚合多个列，那么，所有的聚合都在单个数据传递中的相同操作中进行。

If more than one column is aggregated using the same grouping key or without a grouping key, then all the aggregations are computed within the same operation with a single pass over the data.

youdao