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

java.lang.Object
  org.apache.hadoop.hive.ql.exec.Task<StatsNoJobWork>
      org.apache.hadoop.hive.ql.exec.StatsNoJobTask

All Implemented Interfaces:

Serializable, Node

public class StatsNoJobTask
extends Task<StatsNoJobWork>
implements Serializable

StatsNoJobTask is used in cases where stats collection is the only task for the given query (no parent MR or Tez job). It is used in the following cases 1) ANALYZE with partialscan/noscan for file formats that implement StatsProvidingRecordReader interface: ORC format (implements StatsProvidingRecordReader) stores column statistics for all columns in the file footer. Its much faster to compute the table/partition statistics by reading the footer than scanning all the rows. This task can be used for computing basic stats like numFiles, numRows, fileSize, rawDataSize from ORC footer.

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, COMMON_JOIN, CONVERTED_MAPJOIN, CONVERTED_MAPJOIN_LOCAL, CONVERTED_SORTMERGEJOIN, HINTED_MAPJOIN, HINTED_MAPJOIN_LOCAL, MAPJOIN_ONLY_NOBACKUP, NO_TAG, taskCounters, taskHandle

Constructor Summary

StatsNoJobTask()

Method Summary

int	execute(DriverContext driverContext) This method is overridden in each Task.
String	getName() Gets the name of the node.
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(HiveConf conf, QueryPlan queryPlan, DriverContext driverContext)

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

addDependentTask, done, equals, executeTask, getAndInitBackupTask, getBackupChildrenTasks, getBackupTask, getChildren, getChildTasks, getCounters, getDependentTasks, getDriverContext, getFeedSubscribers, getId, getInitialized, getJobID, getParentTasks, getQueryPlan, getQueued, getReducer, getResultSchema, getTaskHandle, getTaskTag, getTopOperators, getWork, hashCode, hasReduce, ifRetryCmdWhenFail, isLocalMode, isMapRedLocalTask, isMapRedTask, isRootTask, isRunnable, 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

getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

StatsNoJobTask

public StatsNoJobTask()

Method Detail

initialize

public void initialize(HiveConf conf,
                       QueryPlan queryPlan,
                       DriverContext driverContext)

Overrides:

initialize in class Task<StatsNoJobWork>

execute

public int execute(DriverContext driverContext)

Description copied from class: Task

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

Returns:

status of executing the task

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<StatsNoJobWork>

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