org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators
Class POCounter

java.lang.Object
  org.apache.pig.impl.plan.Operator<PhyPlanVisitor>
      org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator
          org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POCounter

All Implemented Interfaces:

Serializable, Cloneable, Comparable<Operator>, Illustrable

public class POCounter
extends PhysicalOperator

This operator is part of the RANK operator implementation. It adds a local counter and a unique task id to each tuple. There are 2 modes of operations: regular and dense. The local counter is depends on the mode of operation. With regular rank is considered duplicate rows while assigning numbers to distinct values groups. With dense rank counts the number of distinct values, without considering duplicate rows. Depending on if it is considered. the entire tuple (row number) or a by a set of columns (rank by). This Physical Operator relies on some specific MR class, available at PigMapReduceCounter.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator

PhysicalOperator.OriginalLocation

Field Summary

protected static TupleFactory

mTupleFactory

Fields inherited from class org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator

alias, illustrator, input, inputAttached, inputs, lineageTracer, outputs, parentPlan, pigLogger, requestedParallelism, res, resultType

Fields inherited from class org.apache.pig.impl.plan.Operator

mKey

Constructor Summary

POCounter(OperatorKey k)

POCounter(OperatorKey k, int rp)

POCounter(OperatorKey k, int rp, List<PhysicalOperator> inputs)

POCounter(OperatorKey operatorKey, int requestedParallelism, List inp, List<PhysicalPlan> counterPlans, List<Boolean> ascendingCol)

POCounter(OperatorKey k, List<PhysicalOperator> inputs)

Method Summary

protected Result	addCounterValue(Result input) Add current task id and local counter value.
void	addToLocalCounter(Long sizeBag)
List<Boolean>	getAscendingColumns()
List<PhysicalPlan>	getCounterPlans()
Long	getLocalCounter()
Result	getNextTuple()
String	getOperationID()
String	getTaskId()
Tuple	illustratorMarkup(Object in, Object out, int eqClassIndex) input tuple mark up to be illustrate-able
Long	incrementLocalCounter() Sequential counter used at ROW NUMBER and RANK BY DENSE mode
boolean	isDenseRank()
boolean	isRowNumber()
String	name()
void	resetLocalCounter() Initialization step into the POCounter is to set up local counter to 1.
void	setAscendingColumns(List<Boolean> mAscCols)
void	setCounterPlans(List<PhysicalPlan> counterPlans)
void	setIsDenseRank(boolean isDenseRank) Dense Rank flag
void	setIsRowNumber(boolean isRowNumber) Row number flag
void	setLocalCounter(Long localCount)
void	setOperationID(String operationID) Operation ID: identifier shared within the corresponding PORank
void	setTaskId(String taskID) Task ID: identifier of the task (map or reducer)
boolean	supportsMultipleInputs() Indicates whether this operator supports multiple inputs.
boolean	supportsMultipleOutputs() Indicates whether this operator supports multiple outputs.
void	visit(PhyPlanVisitor v) Visit this node with the provided visitor.

Methods inherited from class org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator

addOriginalLocation, addOriginalLocation, attachInput, clone, cloneHelper, detachInput, getAlias, getAliasString, getIllustrator, getInputs, getLogger, getNext, getNextBigDecimal, getNextBigInteger, getNextBoolean, getNextDataBag, getNextDataByteArray, getNextDateTime, getNextDouble, getNextFloat, getNextInteger, getNextLong, getNextMap, getNextString, getOriginalLocations, getPigLogger, getReporter, getRequestedParallelism, getResultType, isAccumStarted, isAccumulative, isBlocking, isInputAttached, processInput, reset, setAccumEnd, setAccumStart, setAccumulative, setIllustrator, setInputs, setParentPlan, setPigLogger, setReporter, setRequestedParallelism, setResultType

Methods inherited from class org.apache.pig.impl.plan.Operator

compareTo, equals, getOperatorKey, getProjectionMap, hashCode, regenerateProjectionMap, rewire, toString, unsetProjectionMap

Methods inherited from class java.lang.Object

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

Field Detail

mTupleFactory

protected static final TupleFactory mTupleFactory

Constructor Detail

POCounter

public POCounter(OperatorKey k)

POCounter

public POCounter(OperatorKey k,
                 int rp)

POCounter

public POCounter(OperatorKey k,
                 List<PhysicalOperator> inputs)

POCounter

public POCounter(OperatorKey k,
                 int rp,
                 List<PhysicalOperator> inputs)

POCounter

public POCounter(OperatorKey operatorKey,
                 int requestedParallelism,
                 List inp,
                 List<PhysicalPlan> counterPlans,
                 List<Boolean> ascendingCol)

Method Detail

illustratorMarkup

public Tuple illustratorMarkup(Object in,
                               Object out,
                               int eqClassIndex)

Description copied from interface: Illustrable

input tuple mark up to be illustrate-able

Parameters:

in - input tuple

out - output tuple before wrapped in ExampleTuple

eqClassIndex - index into equivalence classes in illustrator

Returns:

tuple

visit

public void visit(PhyPlanVisitor v)
           throws VisitorException

Description copied from class: Operator

Visit this node with the provided visitor. This should only be called by the visitor class itself, never directly.

Specified by:

visit in class PhysicalOperator

Parameters:

v - Visitor to visit with.

Throws:

VisitorException - if the visitor has a problem.

getNextTuple

public Result getNextTuple()
                    throws ExecException

Overrides:

getNextTuple in class PhysicalOperator

Throws:

ExecException

addCounterValue

protected Result addCounterValue(Result input)
                          throws ExecException

Add current task id and local counter value.

Parameters:

input - from the previous output

Returns:

a tuple within two values prepended to the tuple the task identifier and the local counter value. Local counter value could be incremented by one (is a row number or dense rank) or, could be incremented by the size of the bag on the previous tuple processed

Throws:

ExecException

supportsMultipleInputs

public boolean supportsMultipleInputs()

Description copied from class: Operator

Indicates whether this operator supports multiple inputs.

Specified by:

supportsMultipleInputs in class Operator<PhyPlanVisitor>

Returns:

true if it does, otherwise false.

supportsMultipleOutputs

public boolean supportsMultipleOutputs()

Description copied from class: Operator

Indicates whether this operator supports multiple outputs.

Specified by:

supportsMultipleOutputs in class Operator<PhyPlanVisitor>

Returns:

true if it does, otherwise false.

name

public String name()

Specified by:

name in class Operator<PhyPlanVisitor>

setCounterPlans

public void setCounterPlans(List<PhysicalPlan> counterPlans)

getCounterPlans

public List<PhysicalPlan> getCounterPlans()

setAscendingColumns

public void setAscendingColumns(List<Boolean> mAscCols)

getAscendingColumns

public List<Boolean> getAscendingColumns()

resetLocalCounter

public void resetLocalCounter()

Initialization step into the POCounter is to set up local counter to 1.

incrementLocalCounter

public Long incrementLocalCounter()

Sequential counter used at ROW NUMBER and RANK BY DENSE mode

setLocalCounter

public void setLocalCounter(Long localCount)

getLocalCounter

public Long getLocalCounter()

addToLocalCounter

public void addToLocalCounter(Long sizeBag)

setTaskId

public void setTaskId(String taskID)

Task ID: identifier of the task (map or reducer)

getTaskId

public String getTaskId()

setIsDenseRank

public void setIsDenseRank(boolean isDenseRank)

Dense Rank flag

isDenseRank

public boolean isDenseRank()

setIsRowNumber

public void setIsRowNumber(boolean isRowNumber)

Row number flag

isRowNumber

public boolean isRowNumber()

setOperationID

public void setOperationID(String operationID)

Operation ID: identifier shared within the corresponding PORank

getOperationID

public String getOperationID()