org.apache.calcite.rel.core

Class Collect

java.lang.Object

org.apache.calcite.rel.AbstractRelNode

org.apache.calcite.rel.SingleRel

org.apache.calcite.rel.core.Collect

All Implemented Interfaces:

Cloneable, RelOptNode, RelNode

Direct Known Subclasses:

EnumerableCollect

public class Collect
extends SingleRel

A relational expression that collapses multiple rows into one.

Rules:

• net.sf.farrago.fennel.rel.FarragoMultisetSplitterRule creates a Collect from a call to SqlMultisetValueConstructor or to SqlMultisetQueryConstructor.

Field Summary

Fields

Modifier and Type	Field and Description
protected String	fieldName

Fields inherited from class org.apache.calcite.rel.AbstractRelNode

digest, id, rowType, traitSet

Constructor Summary

Constructors

Constructor and Description
Collect(RelInput input) Creates a Collect by parsing serialized output.
Collect(RelOptCluster cluster, RelTraitSet traitSet, RelNode child, String fieldName) Creates a Collect.

Method Summary

Methods

Modifier and Type	Method and Description
RelNode	copy(RelTraitSet traitSet, List<RelNode> inputs) Creates a copy of this relational expression, perhaps changing traits and inputs.
RelNode	copy(RelTraitSet traitSet, RelNode input)
static RelDataType	deriveCollectRowType(SingleRel rel, String fieldName) Derives the output type of a collect relational expression.
protected RelDataType	deriveRowType()
RelWriter	explainTerms(RelWriter pw) Describes the inputs and attributes of this relational expression.
String	getFieldName() Returns the name of the sole output field.

Methods inherited from class org.apache.calcite.rel.SingleRel

childrenAccept, getInput, getInputs, getRows, replaceInput

Methods inherited from class org.apache.calcite.rel.AbstractRelNode

accept, accept, collectVariablesSet, collectVariablesUsed, computeDigest, computeSelfCost, explain, getChildExps, getCluster, getCollationList, getConvention, getCorrelVariable, getDescription, getDigest, getExpectedInputRowType, getId, getInput, getQuery, getRelTypeName, getRowType, getTable, getTraitSet, getVariablesStopped, isDistinct, isKey, isValid, metadata, onRegister, recomputeDigest, register, sole, toString

Methods inherited from class java.lang.Object

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

Field Detail

fieldName

protected final String fieldName

Constructor Detail

Collect

public Collect(RelOptCluster cluster,
       RelTraitSet traitSet,
       RelNode child,
       String fieldName)

Creates a Collect.

Parameters:

cluster - Cluster

child - Child relational expression

fieldName - Name of the sole output field

Collect

public Collect(RelInput input)

Creates a Collect by parsing serialized output.

Method Detail

copy

public final RelNode copy(RelTraitSet traitSet,
           List<RelNode> inputs)

Description copied from interface: RelNode

Creates a copy of this relational expression, perhaps changing traits and inputs.

Sub-classes with other important attributes are encouraged to create variants of this method with more parameters.

Specified by:

copy in interface RelNode

Overrides:

copy in class AbstractRelNode

Parameters:

traitSet - Trait set

inputs - Inputs

Returns:

Copy of this relational expression, substituting traits and inputs

copy

public RelNode copy(RelTraitSet traitSet,
           RelNode input)

explainTerms

public RelWriter explainTerms(RelWriter pw)

Description copied from class: AbstractRelNode

Describes the inputs and attributes of this relational expression. Each node should call super.explainTerms, then call the RelWriterImpl.input(String, RelNode) and RelWriterImpl.item(String, Object) methods for each input and attribute.

Overrides:

explainTerms in class SingleRel

Parameters:

pw - Plan writer

Returns:

Plan writer for fluent-explain pattern

getFieldName

public String getFieldName()

Returns the name of the sole output field.

Returns:

name of the sole output field

deriveRowType

protected RelDataType deriveRowType()

Overrides:

deriveRowType in class SingleRel

deriveCollectRowType

public static RelDataType deriveCollectRowType(SingleRel rel,
                               String fieldName)

Derives the output type of a collect relational expression.

Parameters:

rel - relational expression

fieldName - name of sole output field

Returns:

output type of a collect relational expression