edu.yale.cs.hadoopdb.exec
Class DBJobBase

java.lang.Object
  org.apache.hadoop.conf.Configured
      edu.yale.cs.hadoopdb.exec.DBJobBase

All Implemented Interfaces:

org.apache.hadoop.conf.Configurable, org.apache.hadoop.util.Tool

Direct Known Subclasses:

AggTaskLargeDB, AggTaskSmallDB, GrepTaskDB, JoinTaskDB, SelectionTaskDB, UDFAggTaskDB

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

DBJobBase is an abstract class for MapReduce jobs that read from a single HadoopDB relation partitioned across multiple databases. It reads in a partition configuration file and retrieves all information about the distribution of the relation and sets up appropriate connections depending on the replication factor setup. Extensions need to configure jobs by implementing configure and implementing necessary Map/Reduce functions.

Nested Class Summary

protected static class

DBJobBase.DBJobBaseInputFormat

Field Summary

static org.apache.commons.logging.Log

LOG

Constructor Summary

DBJobBase()

Method Summary

protected abstract org.apache.hadoop.mapred.JobConf	configureJob(java.lang.String... args) Override this method to set job-specific options
protected org.apache.hadoop.mapred.JobConf	initConf(java.lang.String[] args) Job config initialization (command-line params etc).
int	printDbUsage()
protected abstract int	printUsage() Provide job-specific command-line help
int	run(java.lang.String[] args)

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

LOG

public static final org.apache.commons.logging.Log LOG

Constructor Detail

DBJobBase

public DBJobBase()

Method Detail

configureJob

protected abstract org.apache.hadoop.mapred.JobConf configureJob(java.lang.String... args)
                                                          throws java.lang.Exception

Override this method to set job-specific options

Throws:

java.lang.Exception

initConf

protected org.apache.hadoop.mapred.JobConf initConf(java.lang.String[] args)
                                             throws java.lang.Exception

Job config initialization (command-line params etc).

Throws:

java.lang.Exception

printDbUsage

public int printDbUsage()

printUsage

protected abstract int printUsage()

Provide job-specific command-line help

run

public int run(java.lang.String[] args)
        throws java.lang.Exception

Specified by:

run in interface org.apache.hadoop.util.Tool

Throws:

java.lang.Exception