"for a description of how to handle measures with multiple aggregation functions 关于如何处理多个聚合函数,请参见“
however, you should consider this approach only if memory is a constraint, because performing multiple aggregations within one aggregate transformation serializes the aggregation operations 但是,只有在内存不足时才应考虑这种方法,因为在一个聚合转换内执行多个聚合会序列化聚合操作。
if you need to create multiple aggregations in a data flow, you should consider creating multiple aggregations using one aggregate transformation instead of creating multiple transformations 如果需要在数据流中创建多个聚合,您应该考虑使用一个聚合转换而不是使用多个转换来创建多个聚合。
if you need to create multiple aggregations in a data flow, you should consider creating multiple aggregations using one aggregate transformation instead of creating multiple transformations 如果需要在数据流中创建多个聚合,您应该考虑使用一个聚合转换而不是使用多个转换来创建多个聚合。
unlike symmetric measures, which have one aggregation function applied to the sql expression template for all of the dimensions, asymmetric measures will have multiple aggregation functions applied to the sql template 对于对称的度量,要将一个聚合函数应用于所有维的sql表达式模板;但是非对称度量有多个聚合函数要应用于sql模板。