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

java.lang.Object
  extended by org.apache.pig.newplan.PlanVisitor
      extended by org.apache.pig.newplan.logical.relational.LogicalRelationalNodesVisitor
          extended by 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


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