hadoop - Hadoop Pig 中的点击率计算

Question

需要计算点击率(点击次数超过展示次数，在国家/地区级别)，我列出了表结构(印象表和点击表)，以及我在 Hadoop Pig 中的代码。我的问题是下面的实现是否最有效，还有更有效的解决方案吗？谢谢。

表格印象:

impressionID、时间戳、countryID

点击表格:

impressionID, 时间戳

joined_feed = join impression by impressionID, click by impression ID;
joined_feed = foreach joined_feed generate impression::countryID, click::impressionID is null? 0 : 1 as clicked;
ctr_result = foreach (group joined_feed by country) generate group as countryID, SUM(clicked)/COUNT(joined_feed)

Answer 1

虽然你应该添加类型转换，但你获得点击率的方法非常有效，否则你会得到一堆零和一

ctr_result = foreach (group joined_feed by country) generate group as countryID, (double) SUM(clicked)/(double) COUNT(joined_feed) as ctr