org.apache.calcite.rel

Interface RelDistribution

All Superinterfaces:

RelTrait

public interface RelDistribution
extends RelTrait

Description of the physical distribution of a relational expression.

TBD:

• Can we shorten RelDistribution.Type.HASH_DISTRIBUTED to HASH, etc.
• Do we need RelDistributions.DEFAULT?
• RelDistributionTraitDef.convert(org.apache.calcite.plan.RelOptPlanner, org.apache.calcite.rel.RelNode, org.apache.calcite.rel.RelDistribution, boolean) does not create specific physical operators as it does in Drill. Drill will need to create rules; or we could allow "converters" to be registered with the planner that are not trait-defs.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	RelDistribution.Type Type of distribution.

Method Summary

Methods

Modifier and Type	Method and Description
RelDistribution	apply(Mappings.TargetMapping mapping)
List<Integer>	getKeys() Returns the ordinals of the key columns.
RelDistribution.Type	getType() Returns the type of distribution.

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

equals, getTraitDef, hashCode, register, satisfies, toString

Method Detail

getType

@Nonnull
RelDistribution.Type getType()

Returns the type of distribution.

getKeys

@Nonnull
List<Integer> getKeys()

Returns the ordinals of the key columns.

Order is important for some types (RANGE); other types (HASH) consider it unimportant but impose an arbitrary order; other types (BROADCAST, SINGLETON) never have keys.

apply

RelDistribution apply(Mappings.TargetMapping mapping)