org.apache.hadoop.hive.ql.exec

Class LimitOperator

java.lang.Object

org.apache.hadoop.hive.ql.exec.Operator<LimitDesc>

org.apache.hadoop.hive.ql.exec.LimitOperator

All Implemented Interfaces:

Serializable, Cloneable, Node

Direct Known Subclasses:

VectorLimitOperator

public class LimitOperator
extends Operator<LimitDesc>
implements Serializable

Limit operator implementation Limits the number of rows to be passed on.

See Also:

Serialized Form

Nested Class Summary

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

Operator.OperatorFunc, Operator.State

Field Summary

Fields

Modifier and Type	Field and Description
protected int	currCount
protected boolean	isMap
protected int	leastRow
protected int	limit

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

alias, childOperators, childOperatorsArray, childOperatorsTag, colExprMap, conf, CONTEXT_NAME_KEY, done, groupKeyObject, HIVECOUNTERCREATEDFILES, HIVECOUNTERFATAL, id, inputObjInspectors, isLogDebugEnabled, isLogInfoEnabled, isLogTraceEnabled, LOG, operatorId, out, outputObjInspector, parentOperators, PLOG, reporter, state, statsMap

Constructor Summary

Constructors

Constructor and Description
LimitOperator()

Method Summary

Methods

Modifier and Type	Method and Description
void	closeOp(boolean abort) Operator specific close routine.
String	getName() Implements the getName function for the Node Interface.
static String	getOperatorName()
OperatorType	getType() Return the type of the specific operator among the types in OperatorType.
protected Collection<Future<?>>	initializeOp(org.apache.hadoop.conf.Configuration hconf) Operator specific initialization.
void	process(Object row, int tag) Process the row.

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

acceptLimitPushdown, allInitializedParentsAreClosed, areAllParentsInitialized, augmentPlan, cleanUpInputFileChanged, cleanUpInputFileChangedOp, clone, cloneOp, cloneRecursiveChildren, close, columnNamesRowResolvedCanBeObtained, completeInitializationOp, createDummy, defaultEndGroup, defaultStartGroup, dump, dump, endGroup, flush, forward, getAdditionalCounters, getChildOperators, getChildren, getColumnExprMap, getConf, getConfiguration, getDone, getExecContext, getGroupKeyObject, getIdentifier, getInputObjInspectors, getNextCntr, getNumChild, getNumParent, getOperatorId, getOpTraits, getOutputObjInspector, getParentOperators, getSchema, getStatistics, getStats, initEvaluators, initEvaluators, initEvaluatorsAndReturnStruct, initialize, initialize, initializeChildren, initializeLocalWork, initOperatorId, isUseBucketizedHiveInputFormat, jobClose, jobCloseOp, logStats, opAllowedAfterMapJoin, opAllowedBeforeMapJoin, opAllowedBeforeSortMergeJoin, opAllowedConvertMapJoin, passExecContext, preorderMap, processGroup, removeChild, removeChildAndAdoptItsChildren, removeChildren, removeParent, replaceChild, replaceParent, reset, resetId, resetStats, setAlias, setChildOperators, setColumnExprMap, setConf, setDone, setExecContext, setGroupKeyObject, setId, setInputContext, setInputObjInspectors, setOperatorId, setOpTraits, setOutputCollector, setParentOperators, setReporter, setSchema, setStatistics, setUseBucketizedHiveInputFormat, startGroup, supportAutomaticSortMergeJoin, supportSkewJoinOptimization, supportUnionRemoveOptimization, toString, toString

Methods inherited from class java.lang.Object

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

Field Detail

limit

protected transient int limit

leastRow

protected transient int leastRow

currCount

protected transient int currCount

isMap

protected transient boolean isMap

Constructor Detail

LimitOperator

public LimitOperator()

Method Detail

initializeOp

protected Collection<Future<?>> initializeOp(org.apache.hadoop.conf.Configuration hconf)
                                      throws HiveException

Description copied from class: Operator

Operator specific initialization.

Overrides:

initializeOp in class Operator<LimitDesc>

Throws:

HiveException

process

public void process(Object row,
           int tag)
             throws HiveException

Description copied from class: Operator

Process the row.

Specified by:

process in class Operator<LimitDesc>

Parameters:

row - The object representing the row.

tag - The tag of the row usually means which parent this row comes from. Rows with the same tag should have exactly the same rowInspector all the time.

Throws:

HiveException

getName

public String getName()

Description copied from class: Operator

Implements the getName function for the Node Interface.

Specified by:

getName in interface Node

Overrides:

getName in class Operator<LimitDesc>

Returns:

the name of the operator

getOperatorName

public static String getOperatorName()

getType

public OperatorType getType()

Description copied from class: Operator

Return the type of the specific operator among the types in OperatorType.

Specified by:

getType in class Operator<LimitDesc>

Returns:

OperatorType.*

closeOp

public void closeOp(boolean abort)
             throws HiveException

Description copied from class: Operator

Operator specific close routine. Operators which inherents this class should overwrite this funtion for their specific cleanup routine.

Overrides:

closeOp in class Operator<LimitDesc>

Throws:

HiveException