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.Counter, 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
protected String	limitKey
protected int	offset
protected ObjectCache	runtimeCache

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

abortOp, alias, asyncInitOperations, cContext, childOperators, childOperatorsArray, childOperatorsTag, conf, CONTEXT_NAME_KEY, done, groupKeyObject, HIVE_COUNTER_CREATED_DYNAMIC_PARTITIONS, HIVE_COUNTER_CREATED_FILES, HIVE_COUNTER_FATAL, id, inputObjInspectors, LOG, numRows, operatorId, out, outputObjInspector, parentOperators, reporter, runTimeNumRows, state, statsMap

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	LimitOperator() Kryo ctor.
	LimitOperator(CompilationOpContext ctx)

Method Summary

Modifier and Type	Method and Description
static boolean	checkLimitReached(org.apache.hadoop.mapred.JobConf jobConf)
static boolean	checkLimitReachedForVertex(org.apache.hadoop.mapred.JobConf jobConf, String vertexName)
void	closeOp(boolean abort) Operator specific close routine.
AtomicInteger	getCurrentCount()
static String	getLimitReachedKey(org.apache.hadoop.conf.Configuration conf)
String	getName()
static String	getOperatorName()
OperatorType	getType() Return the type of the specific operator among the types in OperatorType.
protected void	initializeOp(org.apache.hadoop.conf.Configuration hconf) Operator specific initialization.
protected void	onLimitReached()
void	process(Object row, int tag) Process the row.

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

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

Methods inherited from class java.lang.Object

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

Field Detail

limit

protected transient int limit

offset

protected transient int offset

leastRow

protected transient int leastRow

currCount

protected transient int currCount

isMap

protected transient boolean isMap

runtimeCache

protected transient ObjectCache runtimeCache

limitKey

protected transient String limitKey

Constructor Detail

LimitOperator

protected LimitOperator()

Kryo ctor.

LimitOperator

public LimitOperator(CompilationOpContext ctx)

Method Detail

initializeOp

protected void 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()

Specified by:

getName in interface Node

Specified by:

getName in class Operator<LimitDesc>

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.*

onLimitReached

protected void onLimitReached()

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

getCurrentCount

public AtomicInteger getCurrentCount()

getLimitReachedKey

public static String getLimitReachedKey(org.apache.hadoop.conf.Configuration conf)

checkLimitReached

public static boolean checkLimitReached(org.apache.hadoop.mapred.JobConf jobConf)

checkLimitReachedForVertex

public static boolean checkLimitReachedForVertex(org.apache.hadoop.mapred.JobConf jobConf,
                                                 String vertexName)