Package org.apache.calcite.rel.core

Class Uncollect

java.lang.Object

org.apache.calcite.rel.AbstractRelNode

org.apache.calcite.rel.SingleRel

org.apache.calcite.rel.core.Uncollect

All Implemented Interfaces:

Cloneable, RelOptNode, RelNode

Direct Known Subclasses:

EnumerableUncollect

public class Uncollect
extends SingleRel

Relational expression that unnests its input's columns into a relation.

The input may have multiple columns, but each must be a multiset or array. If withOrdinality, the output contains an extra ORDINALITY column.

Like its inverse operation Collect, Uncollect is generally invoked in a nested loop, driven by LogicalCorrelate or similar.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.calcite.rel.RelNode

RelNode.Context

Field Summary

Fields

Modifier and Type	Field	Description
final boolean	withOrdinality

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

input

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

digest, id, rowType, traitSet

Constructor Summary

Constructors

Constructor	Description
Uncollect(RelOptCluster cluster, RelTraitSet traitSet, RelNode child)	Deprecated.
Uncollect(RelOptCluster cluster, RelTraitSet traitSet, RelNode input, boolean withOrdinality, List<String> itemAliases)	Creates an Uncollect.
Uncollect(RelInput input)	Creates an Uncollect by parsing serialized output.

Method Summary

Modifier and Type	Method	Description
final 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 Uncollect	create(RelTraitSet traitSet, RelNode input, boolean withOrdinality, List<String> itemAliases)	Creates an Uncollect.
protected RelDataType	deriveRowType()
static RelDataType	deriveUncollectRowType(RelNode rel, boolean withOrdinality, List<String> itemAliases)	Returns the row type returned by applying the 'UNNEST' operation to a relational expression.
RelWriter	explainTerms(RelWriter pw)	Describes the inputs and attributes of this relational expression.

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

childrenAccept, estimateRowCount, getInput, getInputs, replaceInput

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

accept, accept, collectVariablesSet, collectVariablesUsed, computeSelfCost, deepEquals, deepHashCode, equals, explain, getCluster, getConvention, getCorrelVariable, getDescription, getDigest, getExpectedInputRowType, getId, getInput, getRelDigest, getRelTypeName, getRowType, getTable, getTraitSet, getVariablesSet, hashCode, isEnforcer, isValid, metadata, onRegister, recomputeDigest, register, sole, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.calcite.rel.RelNode

explain, fieldIsNullable, stripped

Field Details

withOrdinality

public final boolean withOrdinality

Constructor Details

Uncollect

@Deprecated
public Uncollect(RelOptCluster cluster,
 RelTraitSet traitSet,
 RelNode child)

Deprecated.

Uncollect

public Uncollect(RelOptCluster cluster,
 RelTraitSet traitSet,
 RelNode input,
 boolean withOrdinality,
 List<String> itemAliases)

Creates an Uncollect.

Use create(org.apache.calcite.plan.RelTraitSet, org.apache.calcite.rel.RelNode, boolean, java.util.List<java.lang.String>) unless you know what you're doing.

Uncollect

public Uncollect(RelInput input)

Creates an Uncollect by parsing serialized output.

Method Details

create

public static Uncollect create(RelTraitSet traitSet,
 RelNode input,
 boolean withOrdinality,
 List<String> itemAliases)

Creates an Uncollect.

Each field of the input relational expression must be an array or multiset.

Parameters:

traitSet - Trait set

input - Input relational expression

withOrdinality - Whether output should contain an ORDINALITY column

itemAliases - Aliases for the operand items

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 RelWriter.input(String, RelNode) and RelWriter.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

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)

deriveRowType

protected RelDataType deriveRowType()

Overrides:

deriveRowType in class SingleRel

deriveUncollectRowType

public static RelDataType deriveUncollectRowType(RelNode rel,
 boolean withOrdinality,
 List<String> itemAliases)

Returns the row type returned by applying the 'UNNEST' operation to a relational expression.

Each column in the relational expression must be a multiset of structs or an array. The return type is the combination of expanding element types from each column, plus an ORDINALITY column if withOrdinality. If itemAliases is not empty, the element types would not expand, each column element outputs as a whole (the return type has same column types as input type).