oracle.spatial.hadoop.vector.join.mapreduce

Class JoinMapper<K,V>

java.lang.Object

org.apache.hadoop.mapreduce.Mapper<org.apache.hadoop.io.NullWritable,org.apache.hadoop.mapreduce.lib.input.FileSplit,JoinGroupWritable,RecordInfo>

oracle.spatial.hadoop.vector.join.mapreduce.JoinMapper<K,V>

Type Parameters:

K - The type of the input keys as read by the internal input format

V - The type of the input values as read by the internal input format

public class JoinMapper<K,V>
extends org.apache.hadoop.mapreduce.Mapper<org.apache.hadoop.io.NullWritable,org.apache.hadoop.mapreduce.lib.input.FileSplit,JoinGroupWritable,RecordInfo>

Maps records from two different data sets to partitions so all the records laying in the same partition can be grouped.
MultipleInputsFileSplitInputFormat needs to be set as the job's input format in order to read two different data sets.
Partitions are read from a previously generated PartitoningResult file which is expected to be found in the distributed cache with the symbolic link ConfigParams.PARTITIONING_RESULT.
For information about generating a PartitioningResult file see Partitioning.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.mapreduce.Mapper

org.apache.hadoop.mapreduce.Mapper.Context

Constructor Summary

Constructors

Constructor and Description
JoinMapper()

Method Summary

Modifier and Type	Method and Description
protected void	map(org.apache.hadoop.io.NullWritable key, org.apache.hadoop.mapreduce.lib.input.FileSplit value, org.apache.hadoop.mapreduce.Mapper.Context context)
protected void	setup(org.apache.hadoop.mapreduce.Mapper.Context context)

Methods inherited from class org.apache.hadoop.mapreduce.Mapper

cleanup, run

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

JoinMapper

public JoinMapper()

Method Detail

setup

protected void setup(org.apache.hadoop.mapreduce.Mapper.Context context)
              throws java.io.IOException,
                     java.lang.InterruptedException

Overrides:

setup in class org.apache.hadoop.mapreduce.Mapper<org.apache.hadoop.io.NullWritable,org.apache.hadoop.mapreduce.lib.input.FileSplit,JoinGroupWritable,RecordInfo>

Throws:

java.io.IOException

java.lang.InterruptedException

map

protected void map(org.apache.hadoop.io.NullWritable key,
                   org.apache.hadoop.mapreduce.lib.input.FileSplit value,
                   org.apache.hadoop.mapreduce.Mapper.Context context)
            throws java.io.IOException,
                   java.lang.InterruptedException

Overrides:

map in class org.apache.hadoop.mapreduce.Mapper<org.apache.hadoop.io.NullWritable,org.apache.hadoop.mapreduce.lib.input.FileSplit,JoinGroupWritable,RecordInfo>

Throws:

java.io.IOException

java.lang.InterruptedException