org.apache.pig.impl.logicalLayer
Class UnionOnSchemaSetter

java.lang.Object
  extended by org.apache.pig.impl.plan.PlanVisitor<LogicalOperator,LogicalPlan>
      extended by org.apache.pig.impl.logicalLayer.LOVisitor
          extended by org.apache.pig.impl.logicalLayer.UnionOnSchemaSetter

public class UnionOnSchemaSetter
extends LOVisitor

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


Field Summary
 
Fields inherited from class org.apache.pig.impl.plan.PlanVisitor
mCurrentWalker, mPlan
 
Constructor Summary
UnionOnSchemaSetter(LogicalPlan plan, PigContext pigContext)
           
 
Method Summary
 void visit(LOUnion loUnion)
           
 
Methods inherited from class org.apache.pig.impl.logicalLayer.LOVisitor
visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, 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.impl.plan.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(LogicalPlan plan,
                           PigContext pigContext)
Method Detail

visit

public void visit(LOUnion loUnion)
           throws PlanValidationException,
                  UnionOnSchemaSetException
Overrides:
visit in class LOVisitor
Throws:
PlanValidationException
UnionOnSchemaSetException


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