点击Hadoop Pig中的点击率计算

Question

需要计算点击率（点击次数与国家/地区级别的展示次数），我列出了表格结构（展示表和点击表格）以及我在Hadoop Pig中的代码。我的问题是，以下实施是否最有效，更有效的解决方案？感谢。

表格印象：

impressionID，timestamp，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

你获得ctr的方法非常有效，虽然你应该添加类型转换或者你会得到一堆零和一个

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