org.apache.hadoop.hive.ql.exec
Class DependencyCollectionTask

java.lang.Object
  org.apache.hadoop.hive.ql.exec.Task<DependencyCollectionWork>
      org.apache.hadoop.hive.ql.exec.DependencyCollectionTask

All Implemented Interfaces:

Serializable, Node

public class DependencyCollectionTask
extends Task<DependencyCollectionWork>
implements Serializable

DependencyCollectionTask. Exists for the sole purpose of reducing the number of dependency edges in the task graph.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.hive.ql.exec.Task

Task.FeedType

Field Summary

Fields inherited from class org.apache.hadoop.hive.ql.exec.Task

BACKUP_COMMON_JOIN, backupChildrenTasks, backupTask, childTasks, clonedConf, COMMON_JOIN, conf, console, CONVERTED_LOCAL_MAPJOIN, CONVERTED_MAPJOIN, db, driverContext, feedSubscribers, id, initialized, isdone, jobID, LOCAL_MAPJOIN, LOG, NO_TAG, parentTasks, queryPlan, queued, started, taskCounters, taskHandle, taskTag, work

Constructor Summary

DependencyCollectionTask()

Method Summary

int	execute(DriverContext driverContext) This method is overridden in each Task.
String	getName() Gets the name of the node.
StageType	getType() Should be overridden to return the type of the specific task among the types in StageType.
protected void	localizeMRTmpFilesImpl(Context ctx) If this task uses any map-reduce intermediate data (either for reading or for writing), localize them (using the supplied Context).

Methods inherited from class org.apache.hadoop.hive.ql.exec.Task

addDependentTask, cloneConf, done, executeTask, fetch, getAndInitBackupTask, getBackupChildrenTasks, getBackupTask, getChildren, getChildTasks, getCounters, getDependentTasks, getFeedSubscribers, getId, getInitialized, getJobID, getParentTasks, getQueryPlan, getQueued, getReducer, getResultSchema, getTaskTag, getTopOperators, getWork, hasReduce, ifRetryCmdWhenFail, initialize, isLocalMode, isMapRedLocalTask, isMapRedTask, isRunnable, localizeMRTmpFiles, pushFeed, receiveFeed, removeDependentTask, removeFromChildrenTasks, requireLock, setBackupChildrenTasks, setBackupTask, setChildTasks, setDone, setFeedSubscribers, setId, setInitialized, setLocalMode, setParentTasks, setQueryPlan, setQueued, setRetryCmdWhenFail, setStarted, setTaskTag, setWork, started, subscribeFeed

Methods inherited from class java.lang.Object

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

Constructor Detail

DependencyCollectionTask

public DependencyCollectionTask()

Method Detail

execute

public int execute(DriverContext driverContext)

Description copied from class: Task

This method is overridden in each Task. TODO execute should return a TaskHandle.

Specified by:

execute in class Task<DependencyCollectionWork>

Returns:

status of executing the task

getType

public StageType getType()

Description copied from class: Task

Should be overridden to return the type of the specific task among the types in StageType.

Specified by:

getType in class Task<DependencyCollectionWork>

Returns:

StageType.* or null if not overridden

getName

public String getName()

Description copied from interface: Node

Gets the name of the node. This is used in the rule dispatchers.

Specified by:

getName in interface Node

Returns:

String

localizeMRTmpFilesImpl

protected void localizeMRTmpFilesImpl(Context ctx)

Description copied from class: Task

If this task uses any map-reduce intermediate data (either for reading or for writing), localize them (using the supplied Context). Map-Reduce intermediate directories are allocated using Context.getMRTmpFileURI() and can be localized using localizeMRTmpFileURI(). This method is declared abstract to force any task code to explicitly deal with this aspect of execution.

Specified by:

localizeMRTmpFilesImpl in class Task<DependencyCollectionWork>

Parameters:

ctx - context object with which to localize