DefaultRelMetadataProvider (Apache Calcite API)

java.lang.Object
- org.apache.calcite.rel.metadata.ChainedRelMetadataProvider
- - org.apache.calcite.rel.metadata.DefaultRelMetadataProvider

All Implemented Interfaces:

RelMetadataProvider
```
public class DefaultRelMetadataProvider
extends ChainedRelMetadataProvider
```
DefaultRelMetadataProvider supplies a default implementation of the RelMetadataProvider interface. It provides generic formulas and derivation rules for the standard logical algebra; coverage corresponds to the methods declared in RelMetadataQuery.

- Field Summary
  
  Fields
  Modifier and Type Field Description
  
  static DefaultRelMetadataProvider INSTANCE
- Constructor Summary
  
  Constructors
  Modifier Constructor Description
  
  protected DefaultRelMetadataProvider()
  Creates a new default provider.
- Method Summary
  - Methods inherited from class org.apache.calcite.rel.metadata.ChainedRelMetadataProvider
    apply, equals, handlers, hashCode, of
  - Methods inherited from class java.lang.Object
    clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - INSTANCE
```
public static final DefaultRelMetadataProvider INSTANCE
```
- Constructor Detail
  - DefaultRelMetadataProvider
```
protected DefaultRelMetadataProvider()
```
    Creates a new default provider. This provider defines "catch-all" handlers for generic RelNodes, so it should always be given lowest priority when chaining.
    Use this constructor only from a sub-class. Otherwise use the singleton instance, INSTANCE.