org.apache.pig.newplan.logical.visitor
Class ProjectStarExpander

java.lang.Object
  org.apache.pig.newplan.PlanVisitor
      org.apache.pig.newplan.logical.relational.LogicalRelationalNodesVisitor
          org.apache.pig.newplan.logical.visitor.ProjectStarExpander

public class ProjectStarExpander
extends LogicalRelationalNodesVisitor

A visitor to walk operators that contain a nested plan and translate project( * ) operators to a list of projection operators, i.e., project( * ) -> project(0), project(1), ... project(n-2), project(n-1) If input schema is null, project(*) is not expanded. It also expands project range ( eg $1 .. $5). It won't expand project-range-to-end (eg $3 ..) if the input schema is null.

Field Summary

Fields inherited from class org.apache.pig.newplan.PlanVisitor

currentWalker, DEFAULT_SCOPE, plan

Constructor Summary

ProjectStarExpander(OperatorPlan plan)

Method Summary

void	visit(LOCogroup cg)
void	visit(LOCube cu)
void	visit(LOForEach foreach)
void	visit(LOJoin join)
void	visit(LORank rank)
void	visit(LOSort sort)

Methods inherited from class org.apache.pig.newplan.logical.relational.LogicalRelationalNodesVisitor

visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit

Methods inherited from class org.apache.pig.newplan.PlanVisitor

getPlan, popWalker, pushWalker, visit

Methods inherited from class java.lang.Object

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

Constructor Detail

ProjectStarExpander

public ProjectStarExpander(OperatorPlan plan)
                    throws FrontendException

Throws:

FrontendException

Method Detail

visit

public void visit(LOSort sort)
           throws FrontendException

Overrides:

visit in class LogicalRelationalNodesVisitor

Throws:

FrontendException

visit

public void visit(LORank rank)
           throws FrontendException

Overrides:

visit in class LogicalRelationalNodesVisitor

Throws:

FrontendException

visit

public void visit(LOCogroup cg)
           throws FrontendException

Overrides:

visit in class LogicalRelationalNodesVisitor

Throws:

FrontendException

visit

public void visit(LOCube cu)
           throws FrontendException

Overrides:

visit in class LogicalRelationalNodesVisitor

Throws:

FrontendException

visit

public void visit(LOJoin join)
           throws FrontendException

Overrides:

visit in class LogicalRelationalNodesVisitor

Throws:

FrontendException

visit

public void visit(LOForEach foreach)
           throws FrontendException

Overrides:

visit in class LogicalRelationalNodesVisitor

Throws:

FrontendException