BuiltInMetadata.NonCumulativeCost (Apache Calcite API)

All Superinterfaces:

Metadata

Enclosing class:

BuiltInMetadata
```
public static interface BuiltInMetadata.NonCumulativeCost
extends Metadata
```
Metadata about the cost of evaluating a relational expression, not including its inputs.

Nested Class Summary

Nested Classes
Modifier and Type Interface Description

static interface BuiltInMetadata.NonCumulativeCost.Handler
Handler API.

Field Summary

Fields
Modifier and Type Field Description

static MetadataDef<BuiltInMetadata.NonCumulativeCost> DEF

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`RelOptCost`	`getNonCumulativeCost()`	Estimates the cost of executing a relational expression, not counting the cost of its inputs.

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

- Field Detail
  - DEF
```
static final MetadataDef<BuiltInMetadata.NonCumulativeCost> DEF
```
- Method Detail
  - getNonCumulativeCost
```
RelOptCost getNonCumulativeCost()
```
    Estimates the cost of executing a relational expression, not counting the cost of its inputs. (However, the non-cumulative cost is still usually dependent on the row counts of the inputs.) The default implementation for this query asks the rel itself via RelNode.computeSelfCost(org.apache.calcite.plan.RelOptPlanner, org.apache.calcite.rel.metadata.RelMetadataQuery), but metadata providers can override this with their own cost models.
    
    Returns:
    
    estimated cost, or null if no reliable estimate can be determined