org.apache.pig.newplan.optimizer

Interface PlanTransformListener

All Known Implementing Classes:

ProjectionPatcher, SchemaPatcher

@InterfaceAudience.Private
 @InterfaceStability.Unstable
public interface PlanTransformListener

An interface to describe listeners that are notified when a plan is modified. The purpose of these listeners is to make modifications to annotations on the plan after the plan is modified. For example, if there is a plan that has ... -> Join -> Filter -> ... which is transformed by pushing the filter before the join, then the input schema of the filter will mostly likely change. A schema listener can be used to make these changes.

Method Summary

Modifier and Type	Method and Description
void	transformed(OperatorPlan fp, OperatorPlan tp) Notification that a plan has been transformed.

Method Detail

transformed

void transformed(OperatorPlan fp,
                 OperatorPlan tp)
          throws FrontendException

Notification that a plan has been transformed. The listener is free in this method to make changes to the annotations on the plan now that it has been transformed.

Parameters:

fp - the full plan that has been transformed

tp - a plan containing only the operators that have been transformed

Throws:

FrontendException