org.apache.hadoop.hive.ql.exec

Class FetchTask

java.lang.Object

org.apache.hadoop.hive.ql.exec.Task<FetchWork>

org.apache.hadoop.hive.ql.exec.FetchTask

All Implemented Interfaces:

Serializable, Node

public class FetchTask
extends Task<FetchWork>
implements Serializable

FetchTask implementation.

See Also:

Serialized Form

Nested Class Summary

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

Task.FeedType, Task.TaskState

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_MAPJOIN, CONVERTED_MAPJOIN_LOCAL, CONVERTED_SORTMERGEJOIN, driverContext, feedSubscribers, HINTED_MAPJOIN, HINTED_MAPJOIN_LOCAL, id, jobID, MAPJOIN_ONLY_NOBACKUP, NO_TAG, parentTasks, queryDisplay, queryPlan, queryState, rootTask, taskCounters, taskHandle, taskTag, work

Constructor Summary

Constructors

Constructor and Description
FetchTask()

Method Summary

Modifier and Type	Method and Description
boolean	canExecuteInParallel()
void	clearFetch() Clear the Fetch Operator.
int	execute(DriverContext driverContext) This method is overridden in each Task.
boolean	fetch(List res)
int	getMaxRows() Return the maximum number of rows returned by fetch.
String	getName() Gets the name of the node.
TableDesc	getTblDesc() Return the tableDesc of the fetchWork.
org.apache.hadoop.hive.ql.plan.api.StageType	getType() Should be overridden to return the type of the specific task among the types in StageType.
void	initialize(QueryState queryState, QueryPlan queryPlan, DriverContext ctx, CompilationOpContext opContext)
boolean	isFetchFrom(FileSinkDesc fs)
void	setMaxRows(int maxRows) Set the maximum number of rows returned by fetch.
void	setValidWriteIdList(String writeIdStr)

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

addDependentTask, cloneConf, done, equals, executeTask, findLeafs, getAndInitBackupTask, getBackupChildrenTasks, getBackupTask, getChildren, getChildTasks, getCounters, getDependentTasks, getDiagnosticsMessage, getDriverContext, getExternalHandle, getFeedSubscribers, getHive, getId, getInitialized, getJobID, getMapWork, getNumChild, getNumParent, getParentTasks, getQueryPlan, getQueryState, getQueued, getReducer, getStatusMessage, getTaskHandle, getTaskState, getTaskTag, getTopOperators, getTxnMgr, getWork, hashCode, hasReduce, isFetchSource, isLocalMode, isMapRedLocalTask, isMapRedTask, isNotInitialized, isRootTask, isRunnable, pushFeed, receiveFeed, removeDependentTask, removeFromChildrenTasks, requireLock, setBackupChildrenTasks, setBackupTask, setChildTasks, setConf, setConsole, setDiagnosticMessage, setDone, setDriverContext, setException, setFeedSubscribers, setFetchSource, setId, setInitialized, setLocalMode, setParentTasks, setQueryDisplay, setQueryPlan, setQueued, setRootTask, setStarted, setState, setStatusMessage, setTaskTag, setWork, shutdown, started, subscribeFeed, toString, updateStatusInQueryDisplay, updateTaskMetrics

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

FetchTask

public FetchTask()

Method Detail

setValidWriteIdList

public void setValidWriteIdList(String writeIdStr)

initialize

public void initialize(QueryState queryState,
                       QueryPlan queryPlan,
                       DriverContext ctx,
                       CompilationOpContext opContext)

Overrides:

initialize in class Task<FetchWork>

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<FetchWork>

Returns:

status of executing the task

getTblDesc

public TableDesc getTblDesc()

Return the tableDesc of the fetchWork.

getMaxRows

public int getMaxRows()

Return the maximum number of rows returned by fetch.

setMaxRows

public void setMaxRows(int maxRows)

Set the maximum number of rows returned by fetch.

fetch

public boolean fetch(List res)
              throws IOException

Throws:

IOException

isFetchFrom

public boolean isFetchFrom(FileSinkDesc fs)

getType

public org.apache.hadoop.hive.ql.plan.api.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<FetchWork>

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

clearFetch

public void clearFetch()
                throws HiveException

Clear the Fetch Operator.

Throws:

HiveException

canExecuteInParallel

public boolean canExecuteInParallel()

Overrides:

canExecuteInParallel in class Task<FetchWork>