org.apache.hadoop.examples
Class Join
java.lang.Object
org.apache.hadoop.conf.Configured
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
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 |
REDUCES_PER_HOST
public static String REDUCES_PER_HOST
Join
public Join()
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