org.apache.flink.optimizer.traversals

Class IdAndEstimatesVisitor

java.lang.Object

org.apache.flink.optimizer.traversals.IdAndEstimatesVisitor

All Implemented Interfaces:

Visitor<OptimizerNode>

public class IdAndEstimatesVisitor
extends Object
implements Visitor<OptimizerNode>

This traversal of the optimizer DAG assigns IDs to each node (in a pre-order fashion), and calls each node to compute its estimates. The latter happens in the postVisit function, where it is guaranteed that all predecessors have computed their estimates.

Constructor Summary

Constructors

Constructor and Description
IdAndEstimatesVisitor(DataStatistics statistics)

Method Summary

Modifier and Type	Method and Description
void	postVisit(OptimizerNode visitable)
boolean	preVisit(OptimizerNode visitable)

Methods inherited from class java.lang.Object

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

Constructor Detail

IdAndEstimatesVisitor

public IdAndEstimatesVisitor(DataStatistics statistics)

Method Detail

preVisit

public boolean preVisit(OptimizerNode visitable)

Specified by:

preVisit in interface Visitor<OptimizerNode>

Returns:

True, if the traversal should continue, false otherwise.

postVisit

public void postVisit(OptimizerNode visitable)

Specified by:

postVisit in interface Visitor<OptimizerNode>