Package org.apache.calcite.rel.metadata

Class RelMdFunctionalDependency

java.lang.Object

org.apache.calcite.rel.metadata.RelMdFunctionalDependency

All Implemented Interfaces:

MetadataHandler<BuiltInMetadata.FunctionalDependency>

public class RelMdFunctionalDependency
extends Object
implements MetadataHandler<BuiltInMetadata.FunctionalDependency>

Default implementation of BuiltInMetadata.FunctionalDependency metadata handler for relational algebra nodes. Uses ArrowSet to represent functional dependencies.

Core functionalities:

• Detects functional dependencies (determines(org.apache.calcite.rel.RelNode, org.apache.calcite.rel.metadata.RelMetadataQuery, int, int), determinesSet(org.apache.calcite.rel.RelNode, org.apache.calcite.rel.metadata.RelMetadataQuery, org.apache.calcite.util.ImmutableBitSet, org.apache.calcite.util.ImmutableBitSet))
• Computes all columns functionally determined by a given set (dependents(org.apache.calcite.rel.RelNode, org.apache.calcite.rel.metadata.RelMetadataQuery, org.apache.calcite.util.ImmutableBitSet))
• Finds minimal determinant sets (determinants(org.apache.calcite.rel.RelNode, org.apache.calcite.rel.metadata.RelMetadataQuery, org.apache.calcite.util.ImmutableBitSet))

See Also:

• Arrow
• ArrowSet

Field Summary

Fields

Modifier and Type	Field	Description
static final RelMetadataProvider	SOURCE

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	RelMdFunctionalDependency()

Method Summary

Modifier and Type	Method	Description
ImmutableBitSet	dependents(RelNode rel, RelMetadataQuery mq, ImmutableBitSet ordinals)	Returns all columns functionally determined by the given columns.
Set<ImmutableBitSet>	determinants(RelNode rel, RelMetadataQuery mq, ImmutableBitSet ordinals)	Returns all minimal determinant sets for the given columns.
@Nullable Boolean	determines(RelNode rel, RelMetadataQuery mq, int determinant, int dependent)	Returns whether one column functionally determines another.
Boolean	determinesSet(RelNode rel, RelMetadataQuery mq, ImmutableBitSet determinants, ImmutableBitSet dependents)	Returns whether a set of columns functionally determines another set.
MetadataDef<BuiltInMetadata.FunctionalDependency>	getDef()
ArrowSet	getFDs(RelNode rel, RelMetadataQuery mq)	Returns all functional dependencies for the given relational node.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

SOURCE

public static final RelMetadataProvider SOURCE

Constructor Details

RelMdFunctionalDependency

protected RelMdFunctionalDependency()

Method Details

getDef

public MetadataDef<BuiltInMetadata.FunctionalDependency> getDef()

Specified by:

getDef in interface MetadataHandler<BuiltInMetadata.FunctionalDependency>

determines

public @Nullable Boolean determines(RelNode rel,
 RelMetadataQuery mq,
 int determinant,
 int dependent)

Returns whether one column functionally determines another.

Parameters:

rel - Relational node

mq - Metadata query

determinant - Determinant column index

dependent - Dependent column index

Returns:

true if determinant determines dependent

determinesSet

public Boolean determinesSet(RelNode rel,
 RelMetadataQuery mq,
 ImmutableBitSet determinants,
 ImmutableBitSet dependents)

Returns whether a set of columns functionally determines another set.

Parameters:

rel - Relational node

mq - Metadata query

determinants - Indices of determinant columns

dependents - Indices of dependent columns

Returns:

true if determinants determine dependents

dependents

public ImmutableBitSet dependents(RelNode rel,
 RelMetadataQuery mq,
 ImmutableBitSet ordinals)

Returns all columns functionally determined by the given columns.

Parameters:

rel - Relational node

mq - Metadata query

ordinals - Indices of input columns

Returns:

Indices of determined columns

determinants

public Set<ImmutableBitSet> determinants(RelNode rel,
 RelMetadataQuery mq,
 ImmutableBitSet ordinals)

Returns all minimal determinant sets for the given columns.

Parameters:

rel - Relational node

mq - Metadata query

ordinals - Indices of columns

Returns:

Minimal determinant sets

getFDs

public ArrowSet getFDs(RelNode rel,
 RelMetadataQuery mq)

Returns all functional dependencies for the given relational node.