org.apache.calcite.plan

Class RelCompositeTrait.EmptyCompositeTrait<T extends RelMultipleTrait>

java.lang.Object

org.apache.calcite.plan.RelCompositeTrait<T>

org.apache.calcite.plan.RelCompositeTrait.EmptyCompositeTrait<T>

Type Parameters:

T - trait type

All Implemented Interfaces:

RelTrait

Enclosing class:

RelCompositeTrait<T extends RelMultipleTrait>

private static class RelCompositeTrait.EmptyCompositeTrait<T extends RelMultipleTrait>
extends RelCompositeTrait<T>

Composite trait with 0 elements.

Constructor Summary

Constructors

Modifier	Constructor and Description
private	EmptyCompositeTrait(RelTraitDef traitDef)

Method Summary

Modifier and Type	Method and Description
boolean	satisfies(RelTrait trait) Returns whether this trait satisfies a given trait.

Methods inherited from class org.apache.calcite.plan.RelCompositeTrait

canonize, equals, getTraitDef, hashCode, of, register, size, toString, trait, traitList

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

EmptyCompositeTrait

private EmptyCompositeTrait(RelTraitDef traitDef)

Method Detail

satisfies

public boolean satisfies(RelTrait trait)

Description copied from interface: RelTrait

Returns whether this trait satisfies a given trait.

A trait satisfies another if it is the same or stricter. For example, ORDER BY x, y satisfies ORDER BY x.

A trait's satisfies relation must be a partial order (reflexive, anti-symmetric, transitive). Many traits cannot be "loosened"; their satisfies is an equivalence relation, where only X satisfies X.

If a trait has multiple values (see RelCompositeTrait) a collection (T0, T1, ...) satisfies T if any Ti satisfies T.

Specified by:

satisfies in interface RelTrait

Overrides:

satisfies in class RelCompositeTrait<T extends RelMultipleTrait>

Parameters:

trait - Given trait

Returns:

Whether this trait subsumes a given trait