org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators
Class PORelationToExprProject

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.expressionOperators.ExpressionOperator
              org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.POProject
                  org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.PORelationToExprProject

All Implemented Interfaces:

Serializable, Cloneable, Comparable<Operator>, Illustrable

public class PORelationToExprProject
extends POProject

Implements a specialized form of POProject which is used *ONLY* in the following case: This project is Project(*) introduced after a relational operator to supply a bag as output (as an expression). This project is either providing the bag as input to a successor expression operator or is itself the leaf in a inner plan If the predecessor relational operator sends an EOP then send an empty bag first to signal "empty" output and then send an EOP NOTE: A Project(*) of return type BAG whose predecessor is from an outside plan (i.e. not in the same inner plan as the project) will NOT lead us here. So a query like: a = load 'baginp.txt' as (b:bag{t:tuple()}); b = foreach a generate $0; dump b; will go through a regular project (without the following flag)

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

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

bagFactory, columns

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

PORelationToExprProject(OperatorKey k)

PORelationToExprProject(OperatorKey k, int rp)

PORelationToExprProject(OperatorKey k, int rp, ArrayList<Integer> cols)

PORelationToExprProject(OperatorKey k, int rp, int col)

Method Summary

PORelationToExprProject	clone() Make a deep copy of this operator.
Result	getNextDataBag()
String	name()
void	reset() Reset internal state in an operator.
void	visit(PhyPlanVisitor v) Visit this node with the provided visitor.

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

attachInput, consumeInputBag, getChildExpressions, getColumn, getColumns, getNext, getNextBigDecimal, getNextBigInteger, getNextBoolean, getNextDataByteArray, getNextDateTime, getNextDouble, getNextFloat, getNextInteger, getNextLong, getNextMap, getNextString, getNextTuple, getStartCol, illustratorMarkup, isOverloaded, isProjectToEnd, isStar, processInputBag, setColumn, setColumns, setOverloaded, setProjectToEnd, setResultSingleTupleBag, setStar, supportsMultipleInputs, supportsMultipleOutputs

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

accumChild, containUDF, setIllustrator, toString

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

addOriginalLocation, addOriginalLocation, cloneHelper, detachInput, getAlias, getAliasString, getIllustrator, getInputs, getLogger, getNext, getOriginalLocations, getPigLogger, getReporter, getRequestedParallelism, getResultType, isAccumStarted, isAccumulative, isBlocking, isInputAttached, processInput, setAccumEnd, setAccumStart, setAccumulative, setInputs, setParentPlan, setPigLogger, setReporter, setRequestedParallelism, setResultType

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

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

Methods inherited from class java.lang.Object

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

Constructor Detail

PORelationToExprProject

public PORelationToExprProject(OperatorKey k)

PORelationToExprProject

public PORelationToExprProject(OperatorKey k,
                               int rp)

PORelationToExprProject

public PORelationToExprProject(OperatorKey k,
                               int rp,
                               int col)

PORelationToExprProject

public PORelationToExprProject(OperatorKey k,
                               int rp,
                               ArrayList<Integer> cols)

Method Detail

name

public String name()

Overrides:

name in class POProject

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.

Overrides:

visit in class POProject

Parameters:

v - Visitor to visit with.

Throws:

VisitorException - if the visitor has a problem.

reset

public void reset()

Description copied from class: PhysicalOperator

Reset internal state in an operator. For use in nested pipelines where operators like limit and sort may need to reset their state. Limit needs it because it needs to know it's seeing a fresh set of input. Blocking operators like sort and distinct need it because they may not have drained their previous input due to a limit and thus need to be told to drop their old input and start over.

Overrides:

reset in class PhysicalOperator

getNextDataBag

public Result getNextDataBag()
                      throws ExecException

Overrides:

getNextDataBag in class POProject

Throws:

ExecException

clone

public PORelationToExprProject clone()
                              throws CloneNotSupportedException

Description copied from class: ExpressionOperator

Make a deep copy of this operator. This is declared here to make it possible to call clone on ExpressionOperators.

Overrides:

clone in class POProject

Throws:

CloneNotSupportedException

See Also:

Do not use the clone method directly. Operators are cloned when logical plans are cloned using {@link LogicalPlanCloner}