查找网页的唯一身份访问者

Question

我想写一个猪脚本，找到一个特定网页的唯一用户ID的数量。

表定义 ： a = (userid:chararray, otherid:chararray, webpage:chararray)

这是我写的，但它不起作用

a = (userid:chararray, otherid:chararray, webpage:chararray)
group_by_page = GROUP a by webpage ;
count_d = FOREACH group_by_page GENERATE group, count(distinct(a.userid));

Answer 1

你需要在嵌套的foreach中使用DISTINCT;它不是UDF。这应该会让你到达你需要去的地方：

a = LOAD 'input' AS (userid:chararray, otherid:chararray, webpage:chararray);
group_by_page = GROUP a by webpage;
count_d = FOREACH group_by_page { uniq = DISTINCT a.userid; GENERATE group, COUNT(uniq); };

转到此处以了解有关嵌套foreach的更多信息。