Hive and Hadoop streaming

[Manhee Jo]

I have some mappers already coded in Java. So I want to use it 
as much as possible in Hive environment. 
Then, how can I call a Java mapper to "select transform" in Hive? 
For example, what is wrong with the query below and why?

INSERT OVERWRITE TABLE u_data_new
SELECT
  TRANSFORM (userid, movieid, rating, unixtime)
  USING 'java WeekdayMapper'
  AS (userid, movieid, rating, weekday)
FROM u_data;

Thank you.


Regards,
Manhee