Package se.liu.ida.hefquin.engine.queryproc.impl.poptimizer.evolutionaryAlgorithm

Class TerminatedByCostValue

java.lang.Object

se.liu.ida.hefquin.engine.queryproc.impl.poptimizer.evolutionaryAlgorithm.TerminationCriterionBase

se.liu.ida.hefquin.engine.queryproc.impl.poptimizer.evolutionaryAlgorithm.TerminatedByCostValue

All Implemented Interfaces:

TerminationCriterion

public class TerminatedByCostValue
extends TerminationCriterionBase

Termination is triggered when the lowest-cost plan per generation has not exceeded a specified threshold for a number of generations.

Field Summary

Fields

Modifier and Type	Field	Description
protected final double	costValueThreshold

Fields inherited from class se.liu.ida.hefquin.engine.queryproc.impl.poptimizer.evolutionaryAlgorithm.TerminationCriterionBase

nrGenerations

Constructor Summary

Constructors

Constructor	Description
TerminatedByCostValue(double costValueThreshold, LogicalPlan plan)

Method Summary

Modifier and Type	Method	Description
static TerminationCriterionFactory	getFactory(double costValueThreshold)
boolean	readyToTerminate(Generation currentGeneration, List<Generation> allPreviousGenerations)	Returns true if this termination criterion has been reached with the current generation.

Methods inherited from class se.liu.ida.hefquin.engine.queryproc.impl.poptimizer.evolutionaryAlgorithm.TerminationCriterionBase

calcFactorial, countNumOfOps

Methods inherited from class java.lang.Object

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

Field Details

costValueThreshold

protected final double costValueThreshold

Constructor Details

TerminatedByCostValue

public TerminatedByCostValue(double costValueThreshold,
 LogicalPlan plan)

Method Details

getFactory

public static TerminationCriterionFactory getFactory(double costValueThreshold)

readyToTerminate

public boolean readyToTerminate(Generation currentGeneration,
 List<Generation> allPreviousGenerations)

Description copied from interface: TerminationCriterion

Returns true if this termination criterion has been reached with the current generation.

Parameters:

currentGeneration - the current generation for which the termination criterion is test

allPreviousGenerations - a list of all previous generations, in the order in which they have been created