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

Interface CardinalityEstimation

All Known Implementing Classes:

CardinalityEstimationImpl, MinBasedCardinalityEstimationImpl

public interface CardinalityEstimation

This interface represents cardinality estimators that can estimate the cardinality of the result that will be produced by query plans. Different implementations of this interface may apply different approaches to estimate the cardinality.

Method Summary

Modifier and Type	Method	Description
CompletableFuture<Integer>	initiateCardinalityEstimation(PhysicalPlan plan)	Asynchronous method that initiates a process to estimate the cardinality of the result that will be produced by the given plan.

Method Details

initiateCardinalityEstimation

CompletableFuture<Integer> initiateCardinalityEstimation(PhysicalPlan plan)

Asynchronous method that initiates a process to estimate the cardinality of the result that will be produced by the given plan. The actual estimate can then be obtained by using the get() method of the returned CompletableFuture. For some helper methods that wrap calls to this method and provide its functionality as synchronous functions, refer to CardinalityEstimationUtils.