org.apache.hadoop.hbase.mapred
Class TableReduce

java.lang.Object
  org.apache.hadoop.mapred.MapReduceBase
      org.apache.hadoop.hbase.mapred.TableReduce

All Implemented Interfaces:

Closeable, JobConfigurable, Reducer

Direct Known Subclasses:

IdentityTableReduce

public abstract class TableReduce
extends MapReduceBase
implements Reducer

Write a table, sorting by the input key

Constructor Summary

TableReduce()
Constructor

Method Summary

static void	initJob(String table, Class<? extends TableReduce> reducer, JobConf job) Use this before submitting a TableReduce job.
abstract void	reduce(Text key, Iterator values, TableOutputCollector output, Reporter reporter)
void	reduce(WritableComparable key, Iterator values, OutputCollector output, Reporter reporter) Create a unique key for table insertion by appending a local counter the given key.

Methods inherited from class org.apache.hadoop.mapred.MapReduceBase

close, configure

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.mapred.JobConfigurable

configure

Methods inherited from interface org.apache.hadoop.io.Closeable

close

Constructor Detail

TableReduce

public TableReduce()

Constructor

Method Detail

initJob

public static void initJob(String table,
                           Class<? extends TableReduce> reducer,
                           JobConf job)

Use this before submitting a TableReduce job. It will appropriately set up the JobConf.

Parameters:

table -

reducer -

job -

reduce

public void reduce(WritableComparable key,
                   Iterator values,
                   OutputCollector output,
                   Reporter reporter)
            throws IOException

Create a unique key for table insertion by appending a local counter the given key.

Specified by:

reduce in interface Reducer

Parameters:

key - the key.

values - the list of values to reduce.

output - to collect keys and combined values.

reporter - facility to report progress.

Throws:

IOException

See Also:

Reducer.reduce(org.apache.hadoop.io.WritableComparable, java.util.Iterator, org.apache.hadoop.mapred.OutputCollector, org.apache.hadoop.mapred.Reporter)

reduce

public abstract void reduce(Text key,
                            Iterator values,
                            TableOutputCollector output,
                            Reporter reporter)
                     throws IOException

Parameters:

key -

values -

output -

reporter -

Throws:

IOException