org.apache.calcite.materialize

Class DelegatingLatticeStatisticProvider

java.lang.Object

org.apache.calcite.materialize.DelegatingLatticeStatisticProvider

All Implemented Interfaces:

LatticeStatisticProvider

public class DelegatingLatticeStatisticProvider
extends Object
implements LatticeStatisticProvider

Implementation of LatticeStatisticProvider that delegates to an underlying provider.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.calcite.materialize.LatticeStatisticProvider

LatticeStatisticProvider.Factory

Field Summary

Fields

Modifier and Type	Field and Description
protected LatticeStatisticProvider	provider

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	DelegatingLatticeStatisticProvider(LatticeStatisticProvider provider) Creates a DelegatingLatticeStatisticProvider.

Method Summary

Modifier and Type	Method and Description
double	cardinality(List<Lattice.Column> columns) Returns an estimate of the number of distinct values in a column or list of columns.

Methods inherited from class java.lang.Object

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

Field Detail

provider

protected final LatticeStatisticProvider provider

Constructor Detail

DelegatingLatticeStatisticProvider

protected DelegatingLatticeStatisticProvider(LatticeStatisticProvider provider)

Creates a DelegatingLatticeStatisticProvider.

Parameters:

provider - Provider to which to delegate otherwise unhandled requests

Method Detail

cardinality

public double cardinality(List<Lattice.Column> columns)

Description copied from interface: LatticeStatisticProvider

Returns an estimate of the number of distinct values in a column or list of columns.

Specified by:

cardinality in interface LatticeStatisticProvider