org.apache.calcite.plan

Interface Convention

All Superinterfaces:

RelTrait

All Known Implementing Classes:

BindableConvention, Convention.Impl, EnumerableConvention, InterpretableConvention, JdbcConvention

public interface Convention
extends RelTrait

Calling convention trait.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	Convention.Impl Default implementation.

Field Summary

Fields

Modifier and Type	Field and Description
static Convention	NONE Convention that for a relational expression that does not support any convention.

Method Summary

Modifier and Type	Method and Description
default boolean	canConvertConvention(Convention toConvention) Returns whether we should convert from this convention to toConvention.
default @Nullable RelNode	enforce(RelNode input, RelTraitSet required) Given an input and required traits, returns the corresponding enforcer rel nodes, like physical Sort, Exchange etc.
Class	getInterface()
String	getName()
default RelFactories.Struct	getRelFactories() Return RelFactories struct for this convention.
default boolean	useAbstractConvertersForConversion(RelTraitSet fromTraits, RelTraitSet toTraits) Returns whether we should convert from this trait set to the other trait set.

Methods inherited from interface org.apache.calcite.plan.RelTrait

apply, equals, getTraitDef, hashCode, isDefault, register, satisfies, toString

Field Detail

NONE

static final Convention NONE

Convention that for a relational expression that does not support any convention. It is not implementable, and has to be transformed to something else in order to be implemented.

Relational expressions generally start off in this form.

Such expressions always have infinite cost.

Method Detail

getInterface

Class getInterface()

getName

String getName()

enforce

default @Nullable RelNode enforce(RelNode input,
                                  RelTraitSet required)

Given an input and required traits, returns the corresponding enforcer rel nodes, like physical Sort, Exchange etc.

Parameters:

input - The input RelNode

required - The required traits

Returns:

Physical enforcer that satisfies the required traitSet, or null if trait enforcement is not allowed or the required traitSet can't be satisfied.

canConvertConvention

default boolean canConvertConvention(Convention toConvention)

Returns whether we should convert from this convention to toConvention. Used by ConventionTraitDef.

Parameters:

toConvention - Desired convention to convert to

Returns:

Whether we should convert from this convention to toConvention

useAbstractConvertersForConversion

default boolean useAbstractConvertersForConversion(RelTraitSet fromTraits,
                                                   RelTraitSet toTraits)

Returns whether we should convert from this trait set to the other trait set.

The convention decides whether it wants to handle other trait conversions, e.g. collation, distribution, etc. For a given convention, we will only add abstract converters to handle the trait (convention, collation, distribution, etc.) conversions if this function returns true.

Parameters:

fromTraits - Traits of the RelNode that we are converting from

toTraits - Target traits

Returns:

Whether we should add converters

getRelFactories

default RelFactories.Struct getRelFactories()

Return RelFactories struct for this convention. It can can be used to build RelNode.