org.apache.flink.optimizer.traversals

Class InterestingPropertyVisitor

java.lang.Object

org.apache.flink.optimizer.traversals.InterestingPropertyVisitor

All Implemented Interfaces:

Visitor<OptimizerNode>

public class InterestingPropertyVisitor
extends Object
implements Visitor<OptimizerNode>

Visitor that computes the interesting properties for each node in the optimizer DAG. On its recursive depth-first descend, it propagates all interesting properties top-down.

Constructor Summary

Constructors

Constructor and Description
InterestingPropertyVisitor(CostEstimator estimator) Creates a new visitor that computes the interesting properties for all nodes in the plan.

Method Summary

Modifier and Type	Method and Description
void	postVisit(OptimizerNode visitable) Method that is invoked after all child nodes or descendant nodes were visited.
boolean	preVisit(OptimizerNode node) Method that is invoked on the visit before visiting and child nodes or descendant nodes.

Methods inherited from class java.lang.Object

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

Constructor Detail

InterestingPropertyVisitor

public InterestingPropertyVisitor(CostEstimator estimator)

Creates a new visitor that computes the interesting properties for all nodes in the plan. It uses the given cost estimator used to compute the maximal costs for an interesting property.

Parameters:

estimator - The cost estimator to estimate the maximal costs for interesting properties.

Method Detail

preVisit

public boolean preVisit(OptimizerNode node)

Description copied from interface: Visitor

Method that is invoked on the visit before visiting and child nodes or descendant nodes.

Specified by:

preVisit in interface Visitor<OptimizerNode>

Returns:

True, if the traversal should continue, false otherwise.

postVisit

public void postVisit(OptimizerNode visitable)

Description copied from interface: Visitor

Method that is invoked after all child nodes or descendant nodes were visited.

Specified by:

postVisit in interface Visitor<OptimizerNode>