Package org.apache.calcite.rel.metadata

Interface BuiltInMetadata.Distribution

All Superinterfaces:

Metadata

Enclosing class:

BuiltInMetadata

public static interface BuiltInMetadata.Distribution
extends Metadata

Metadata about how a relational expression is distributed.

If you are an operator consuming a relational expression, which subset of the rows are you seeing? You might be seeing all of them (BROADCAST or SINGLETON), only those whose key column values have a particular hash code (HASH) or only those whose column values have particular values or ranges of values (RANGE).

When a relational expression is partitioned, it is often partitioned among nodes, but it may be partitioned among threads running on the same node.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static interface	BuiltInMetadata.Distribution.Handler	Handler API.

Field Summary

Fields

Modifier and Type	Field	Description
static final MetadataDef<BuiltInMetadata.Distribution>	DEF

Method Summary

Modifier and Type	Method	Description
RelDistribution	distribution()	Determines how the rows are distributed.

Methods inherited from interface org.apache.calcite.rel.metadata.Metadata

rel

Field Details

DEF

static final MetadataDef<BuiltInMetadata.Distribution> DEF

Method Details

distribution

RelDistribution distribution()

Determines how the rows are distributed.