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

java.lang.Object
  org.apache.hadoop.hive.ql.exec.Task<StatsWork>
      org.apache.hadoop.hive.ql.exec.StatsTask

All Implemented Interfaces:

Serializable, Node

public class StatsTask
extends Task<StatsWork>
implements Serializable

StatsTask implementation. StatsTask mainly deals with "collectable" stats. These are stats that require data scanning and are collected during query execution (unless the user explicitly requests data scanning just for the purpose of stats computation using the "ANALYZE" command. All other stats are computed directly by the MetaStore. The rationale being that the MetaStore layer covers all Thrift calls and provides better guarantees about the accuracy of those stats.

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_MAPJOIN, CONVERTED_MAPJOIN_LOCAL, CONVERTED_SORTMERGEJOIN, db, driverContext, feedSubscribers, HINTED_MAPJOIN, HINTED_MAPJOIN_LOCAL, id, initialized, isdone, jobID, MAPJOIN_ONLY_NOBACKUP, NO_TAG, parentTasks, queryPlan, queued, rootTask, started, taskCounters, taskHandle, taskTag, work

Constructor Summary

StatsTask()

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	receiveFeed(Task.FeedType feedType, Object feedValue)

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

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

Methods inherited from class java.lang.Object

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

Constructor Detail

StatsTask

public StatsTask()

Method Detail

receiveFeed

protected void receiveFeed(Task.FeedType feedType,
                           Object feedValue)

Overrides:

receiveFeed in class Task<StatsWork>

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<StatsWork>

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<StatsWork>

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