Package org.apache.wayang.basic.operators

Class TextFileSource.CardinalityEstimator

java.lang.Object

org.apache.wayang.basic.operators.TextFileSource.CardinalityEstimator

All Implemented Interfaces:

Serializable, CardinalityEstimator

Enclosing class:

TextFileSource

protected class TextFileSource.CardinalityEstimator
extends Object
implements CardinalityEstimator

Custom CardinalityEstimator for FlatMapOperators.

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
static final double	CORRECTNESS_PROBABILITY
static final double	EXPECTED_ESTIMATE_DEVIATION	We expect selectivities to be correct within a factor of 0.05.
final CardinalityEstimate	FALLBACK_ESTIMATE

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	CardinalityEstimator()

Method Summary

Modifier and Type	Method	Description
CardinalityEstimate	estimate(OptimizationContext optimizationContext, CardinalityEstimate... inputEstimates)

Methods inherited from class java.lang.Object

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

Field Details

FALLBACK_ESTIMATE

public final CardinalityEstimate FALLBACK_ESTIMATE

CORRECTNESS_PROBABILITY

public static final double CORRECTNESS_PROBABILITY

See Also:

• Constant Field Values

EXPECTED_ESTIMATE_DEVIATION

public static final double EXPECTED_ESTIMATE_DEVIATION

We expect selectivities to be correct within a factor of 0.05.

See Also:

• Constant Field Values

Constructor Details

CardinalityEstimator

protected CardinalityEstimator()

Method Details

estimate

public CardinalityEstimate estimate(OptimizationContext optimizationContext,
 CardinalityEstimate... inputEstimates)

Specified by:

estimate in interface CardinalityEstimator