org.apache.flink.optimizer.costs

类 DefaultCostEstimator

java.lang.Object

org.apache.flink.optimizer.costs.CostEstimator

org.apache.flink.optimizer.costs.DefaultCostEstimator

public class DefaultCostEstimator
extends CostEstimator

A default cost estimator that has access to basic size and cardinality estimates.

This estimator works with actual estimates (as far as they are available) and falls back to setting relative costs, if no estimates are available. That way, the estimator makes sure that plans with different strategies are costed differently, also in the absence of estimates. The different relative costs in the absence of estimates represent this estimator's heuristic guidance towards certain strategies.

For robustness reasons, we always assume that the whole data is shipped during a repartition step. We deviate from the typical estimate of (n - 1) / n (with n being the number of nodes), because for a parallelism of 1, that would yield a shipping of zero bytes. While this is usually correct, the runtime scheduling may still choose to move tasks to different nodes, so that we do not know that no data is shipped.

构造器概要

构造器

构造器和说明
DefaultCostEstimator()

方法概要

限定符和类型	方法和说明
void	addArtificialDamCost(EstimateProvider estimates, long bufferSize, Costs costs)
void	addBlockNestedLoopsCosts(EstimateProvider outerSide, EstimateProvider innerSide, long blockSize, Costs costs, int costWeight)
void	addBroadcastCost(EstimateProvider estimates, int replicationFactor, Costs costs)
void	addCachedHybridHashCosts(EstimateProvider buildSideInput, EstimateProvider probeSideInput, Costs costs, int costWeight) Calculates the costs for the cached variant of the hybrid hash join.
void	addFileInputCost(long fileSizeInBytes, Costs costs)
void	addHashPartitioningCost(EstimateProvider estimates, Costs costs)
void	addHybridHashCosts(EstimateProvider buildSideInput, EstimateProvider probeSideInput, Costs costs, int costWeight)
void	addLocalMergeCost(EstimateProvider input1, EstimateProvider input2, Costs costs, int costWeight)
void	addLocalSortCost(EstimateProvider estimates, Costs costs)
void	addRandomPartitioningCost(EstimateProvider estimates, Costs costs)
void	addRangePartitionCost(EstimateProvider estimates, Costs costs)
void	addStreamedNestedLoopsCosts(EstimateProvider outerSide, EstimateProvider innerSide, long bufferSize, Costs costs, int costWeight)

从类继承的方法 org.apache.flink.optimizer.costs.CostEstimator

costOperator

从类继承的方法 java.lang.Object

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

构造器详细资料

DefaultCostEstimator

public DefaultCostEstimator()

方法详细资料

addRandomPartitioningCost

public void addRandomPartitioningCost(EstimateProvider estimates,
                                      Costs costs)

指定者:

addRandomPartitioningCost 在类中 CostEstimator

addHashPartitioningCost

public void addHashPartitioningCost(EstimateProvider estimates,
                                    Costs costs)

指定者:

addHashPartitioningCost 在类中 CostEstimator

addRangePartitionCost

public void addRangePartitionCost(EstimateProvider estimates,
                                  Costs costs)

指定者:

addRangePartitionCost 在类中 CostEstimator

addBroadcastCost

public void addBroadcastCost(EstimateProvider estimates,
                             int replicationFactor,
                             Costs costs)

指定者:

addBroadcastCost 在类中 CostEstimator

addFileInputCost

public void addFileInputCost(long fileSizeInBytes,
                             Costs costs)

指定者:

addFileInputCost 在类中 CostEstimator

addLocalSortCost

public void addLocalSortCost(EstimateProvider estimates,
                             Costs costs)

指定者:

addLocalSortCost 在类中 CostEstimator

addLocalMergeCost

public void addLocalMergeCost(EstimateProvider input1,
                              EstimateProvider input2,
                              Costs costs,
                              int costWeight)

指定者:

addLocalMergeCost 在类中 CostEstimator

addHybridHashCosts

public void addHybridHashCosts(EstimateProvider buildSideInput,
                               EstimateProvider probeSideInput,
                               Costs costs,
                               int costWeight)

指定者:

addHybridHashCosts 在类中 CostEstimator

addCachedHybridHashCosts

public void addCachedHybridHashCosts(EstimateProvider buildSideInput,
                                     EstimateProvider probeSideInput,
                                     Costs costs,
                                     int costWeight)

Calculates the costs for the cached variant of the hybrid hash join. We are assuming by default that half of the cached hash table fit into memory.

指定者:

addCachedHybridHashCosts 在类中 CostEstimator

addStreamedNestedLoopsCosts

public void addStreamedNestedLoopsCosts(EstimateProvider outerSide,
                                        EstimateProvider innerSide,
                                        long bufferSize,
                                        Costs costs,
                                        int costWeight)

指定者:

addStreamedNestedLoopsCosts 在类中 CostEstimator

addBlockNestedLoopsCosts

public void addBlockNestedLoopsCosts(EstimateProvider outerSide,
                                     EstimateProvider innerSide,
                                     long blockSize,
                                     Costs costs,
                                     int costWeight)

指定者:

addBlockNestedLoopsCosts 在类中 CostEstimator

addArtificialDamCost

public void addArtificialDamCost(EstimateProvider estimates,
                                 long bufferSize,
                                 Costs costs)

指定者:

addArtificialDamCost 在类中 CostEstimator