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

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

public class UnionOnSchemaSetter
extends LogicalRelationalNodesVisitor

A visitor that modifies the logical plan (if necessary) for union-onschema functionality. It runs logical plan validator so that the correct schema of its inputs is available. It inserts foreach statements in its input if the input operator schema does not match the schema created by merging all input schemas. Migrated from the old UnionOnSchemaSetter class.

Field Summary

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

currentWalker, DEFAULT_SCOPE, plan

Constructor Summary

UnionOnSchemaSetter(OperatorPlan plan)

Method Summary

void	visit(LOUnion union)

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

visit, visit, visit, visit, visit, 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

UnionOnSchemaSetter

public UnionOnSchemaSetter(OperatorPlan plan)
                    throws FrontendException

Throws:

FrontendException

Method Detail

visit

public void visit(LOUnion union)
           throws FrontendException

Overrides:

visit in class LogicalRelationalNodesVisitor

Throws:

FrontendException