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

java.lang.Object
  extended by org.apache.hadoop.hive.ql.exec.Operator<LimitDesc>
      extended by org.apache.hadoop.hive.ql.exec.LimitOperator
All Implemented Interfaces:
Serializable, Node

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.ProgressCounter, Operator.State
 
Field Summary
protected  int currCount
           
protected  boolean isMap
           
protected  int leastRow
           
protected  int limit
           
 
Fields inherited from class org.apache.hadoop.hive.ql.exec.Operator
alias, beginTime, childOperators, childOperatorsArray, childOperatorsTag, colExprMap, conf, counterNames, counterNameToEnum, counters, done, fatalErrorCntr, groupKeyObject, id, inputObjInspectors, inputRows, isLogInfoEnabled, LOG, numInputRowsCntr, numOutputRowsCntr, operatorId, out, outputObjInspector, outputRows, parentOperators, reporter, state, statsMap, timeTakenCntr, totalTime
 
Constructor Summary
LimitOperator()
           
 
Method Summary
 void closeOp(boolean abort)
          Operator specific close routine.
 String getName()
          Implements the getName function for the Node Interface.
 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.
 void processOp(Object row, int tag)
          Process the row.
 
Methods inherited from class org.apache.hadoop.hive.ql.exec.Operator
allInitializedParentsAreClosed, areAllParentsInitialized, assignCounterNameToEnum, augmentPlan, checkFatalErrors, cleanUpInputFileChanged, cleanUpInputFileChangedOp, close, dump, dump, endGroup, fatalErrorMessage, forward, getChildOperators, getChildren, getColumnExprMap, getConf, getCounterNames, getCounterNameToEnum, getCounters, getDone, getExecContext, getGroupKeyObject, getIdentifier, getInputObjInspectors, getOperatorId, getParentOperators, getSchema, getStats, incrCounter, initEvaluators, initEvaluators, initEvaluatorsAndReturnStruct, initialize, initializeChildren, initializeCounters, initializeLocalWork, initOperatorId, jobClose, logStats, passExecContext, preorderMap, process, removeChild, removeChildAndAdoptItsChildren, removeParent, replaceChild, replaceParent, reset, resetId, resetLastEnumUsed, resetStats, setAlias, setChildOperators, setColumnExprMap, setConf, setCounterNames, setCounterNameToEnum, setDone, setExecContext, setGroupKeyObject, setId, setInputObjInspectors, setOperatorId, setOutputCollector, setParentOperators, setReporter, setSchema, startGroup, updateCounters
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, 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 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

processOp

public void processOp(Object row,
                      int tag)
               throws HiveException
Description copied from class: Operator
Process the row.

Specified by:
processOp 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

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


Copyright © 2011 The Apache Software Foundation