edu.yale.cs.hadoopdb.connector
Class DBInputFormat<T extends DBWritable>

java.lang.Object
  extended by edu.yale.cs.hadoopdb.connector.DBInputFormat<T>
Type Parameters:
T -
All Implemented Interfaces:
org.apache.hadoop.mapred.InputFormat<org.apache.hadoop.io.LongWritable,T>, org.apache.hadoop.mapred.JobConfigurable
Direct Known Subclasses:
DBJobBase.DBJobBaseInputFormat

public abstract class DBInputFormat<T extends DBWritable>
extends java.lang.Object
implements org.apache.hadoop.mapred.InputFormat<org.apache.hadoop.io.LongWritable,T>, org.apache.hadoop.mapred.JobConfigurable

Base DBInputFormat class. Extensions required to specialize value class.


Field Summary
protected  DBConfiguration dbConf
           
 
Constructor Summary
DBInputFormat()
           
 
Method Summary
 void configure(org.apache.hadoop.mapred.JobConf conf)
          Method necessary for JobConfigurable interface.
 org.apache.hadoop.mapred.RecordReader<org.apache.hadoop.io.LongWritable,T> getRecordReader(org.apache.hadoop.mapred.InputSplit split, org.apache.hadoop.mapred.JobConf job, org.apache.hadoop.mapred.Reporter reporter)
          Returns DBRecordReader for a given split.
 org.apache.hadoop.mapred.InputSplit[] getSplits(org.apache.hadoop.mapred.JobConf conf, int numSplits)
          Retrieves the location of chunks for a given relation.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

dbConf

protected DBConfiguration dbConf
Constructor Detail

DBInputFormat

public DBInputFormat()
Method Detail

configure

public void configure(org.apache.hadoop.mapred.JobConf conf)
Method necessary for JobConfigurable interface. We allow different extensions to utilize different information from the Hadoop JobConf object.

Specified by:
configure in interface org.apache.hadoop.mapred.JobConfigurable

getRecordReader

public org.apache.hadoop.mapred.RecordReader<org.apache.hadoop.io.LongWritable,T> getRecordReader(org.apache.hadoop.mapred.InputSplit split,
                                                                                                  org.apache.hadoop.mapred.JobConf job,
                                                                                                  org.apache.hadoop.mapred.Reporter reporter)
                                                                                                              throws java.io.IOException
Returns DBRecordReader for a given split.

Specified by:
getRecordReader in interface org.apache.hadoop.mapred.InputFormat<org.apache.hadoop.io.LongWritable,T extends DBWritable>
Throws:
java.io.IOException

getSplits

public org.apache.hadoop.mapred.InputSplit[] getSplits(org.apache.hadoop.mapred.JobConf conf,
                                                       int numSplits)
                                                throws java.io.IOException
Retrieves the location of chunks for a given relation. Then, it creates as many splits as the number of chunks. Each split is assigned a chunk (which holds connection and location information).

Specified by:
getSplits in interface org.apache.hadoop.mapred.InputFormat<org.apache.hadoop.io.LongWritable,T extends DBWritable>
Throws:
java.io.IOException