您也许已经注意到，中间结果中并不包含任何表示当前分组的信息。
As you might notice, the intermediate result does not contain any information about the current group.
可用一个属性保存中间结果列表，其中的每一个元素都代表一个分组的聚集信息。
We use an attribute for a list of intermediate results, where one element of the list represents the aggregation information for one group.
从清单 4 中您可以看到，为每一个分组计算中间结果并保存在内存中的部分都用 粗体标识出来。
Referring to listing 4, you can find the calculation of the new aggregate information that is kept in memory for each group set in bold.
应用推荐