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.
Selection of part of a wave on account of time or magnitude. Operation of a circuit when one wave allows another to pass during specific intervals.
根据时间或幅度选择波形的一部分，即在一个特定的间隔里一个波形允许另一个波形通过电路的动作。
3
The Third Party Logistics is one kind of advanced organization pattern of Logistics, To realize the value of Logistics must pass the operation of the corporation of Logistics.