org.apache.hadoop.examples
Class Join

java.lang.Object
  extended by org.apache.hadoop.conf.Configured
      extended by org.apache.hadoop.examples.Join
All Implemented Interfaces:
org.apache.hadoop.conf.Configurable, org.apache.hadoop.util.Tool

public class Join
extends org.apache.hadoop.conf.Configured
implements org.apache.hadoop.util.Tool

Given a set of sorted datasets keyed with the same class and yielding equal partitions, it is possible to effect a join of those datasets prior to the map. The example facilitates the same. To run: bin/hadoop jar build/hadoop-examples.jar join [-r reduces] [-inFormat input format class] [-outFormat output format class] [-outKey output key class] [-outValue output value class] [-joinOp <inner|outer|override>] [in-dir]* in-dir out-dir


Field Summary
static String REDUCES_PER_HOST
           
 
Constructor Summary
Join()
           
 
Method Summary
static void main(String[] args)
           
 int run(String[] args)
          The main driver for sort program.
 
Methods inherited from class org.apache.hadoop.conf.Configured
getConf, setConf
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface org.apache.hadoop.conf.Configurable
getConf, setConf
 

Field Detail

REDUCES_PER_HOST

public static String REDUCES_PER_HOST
Constructor Detail

Join

public Join()
Method Detail

run

public int run(String[] args)
        throws Exception
The main driver for sort program. Invoke this method to submit the map/reduce job.

Specified by:
run in interface org.apache.hadoop.util.Tool
Throws:
IOException - When there is communication problems with the job tracker.
Exception

main

public static void main(String[] args)
                 throws Exception
Throws:
Exception


Copyright © 2009 The Apache Software Foundation