org.apache.calcite.rel.metadata

Interface BuiltInMetadata.CumulativeCost

All Superinterfaces:

Metadata

Enclosing class:

BuiltInMetadata

public static interface BuiltInMetadata.CumulativeCost
extends Metadata

Metadata about the cost of evaluating a relational expression, including all of its inputs.

Nested Class Summary

Nested Classes

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

Field Summary

Fields

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

Method Summary

Modifier and Type	Method and Description
RelOptCost	getCumulativeCost() Estimates the cost of executing a relational expression, including the cost of its inputs.

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

rel

Field Detail

DEF

static final MetadataDef<BuiltInMetadata.CumulativeCost> DEF

Method Detail

getCumulativeCost

RelOptCost getCumulativeCost()

Estimates the cost of executing a relational expression, including the cost of its inputs. The default implementation for this query adds BuiltInMetadata.NonCumulativeCost.getNonCumulativeCost() to the cumulative cost of each input, but metadata providers can override this with their own cost models, e.g. to take into account interactions between expressions.

Returns:

estimated cost, or null if no reliable estimate can be determined