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.

Method Summary

Methods

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

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