org.apache.calcite.rel.metadata

Interface BuiltInMetadata.MinRowCount

All Superinterfaces:

Metadata

Enclosing class:

BuiltInMetadata

public static interface BuiltInMetadata.MinRowCount
extends Metadata

Metadata about the minimum number of rows returned by a relational expression.

Nested Class Summary

Nested Classes

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

Field Summary

Fields

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

Method Summary

Modifier and Type	Method and Description
@Nullable Double	getMinRowCount() Estimates the minimum number of rows which will be returned by a relational expression.

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

rel

Field Detail

DEF

static final MetadataDef<BuiltInMetadata.MinRowCount> DEF

Method Detail

getMinRowCount

@Nullable Double getMinRowCount()

Estimates the minimum number of rows which will be returned by a relational expression.

The default implementation for this query returns 0, but metadata providers can override this with their own cost models.

Returns:

lower bound on the number of rows returned