Java programming Conditional select

[Rob Stewart <ro...@googlemail.com>]

Hi folks,

I am trying to provide a comparative study on the various Hadoop languages.
 I have all but completed the implementation in JAQL, Pig and Hive for the
tasks, leaving Java MR to last.

The applications are simple, and they include:
1. Conditional Select (A and B would be read from files A.dat and B.dat)
--------------
select A.filename from A, B where A.filename = B.filename
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2. Aggregate select (would be read from a delimited file webLog.dat)
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select userID, AVG(timeOnSite) as averages, COUNT(pageID)
group by userID
order by averages DESC;
--------------


My question is... Can these
A) Be found in the packaged hadoop-examples.jar (I know wordcount is).
B) Be implemented in a straight forward way in Java MapReduce
C) Be implemented with some obvious API method calls within Hadoop that I
have not yet found?