org.apache.calcite.rel.core

Class Project

java.lang.Object

org.apache.calcite.rel.AbstractRelNode

org.apache.calcite.rel.SingleRel

org.apache.calcite.rel.core.Project

All Implemented Interfaces:

Cloneable, RelOptNode, Hintable, RelNode

Direct Known Subclasses:

Bindables.BindableProject, EnumerableProject, JdbcRules.JdbcProject, LogicalProject

public abstract class Project
extends SingleRel
implements Hintable

Relational expression that computes a set of 'select expressions' from its input relational expression.

See Also:

LogicalProject

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Project.Flags Deprecated.

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

RelNode.Context

Field Summary

Fields

Modifier and Type	Field and Description
protected com.google.common.collect.ImmutableList<RexNode>	exps
protected com.google.common.collect.ImmutableList<RelHint>	hints

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

Modifier	Constructor and Description
protected	Project(RelInput input) Creates a Project by parsing serialized output.
protected	Project(RelOptCluster cluster, RelTraitSet traits, List<RelHint> hints, RelNode input, List<? extends RexNode> projects, RelDataType rowType) Creates a Project.
protected	Project(RelOptCluster cluster, RelTraitSet traits, RelNode input, List<? extends RexNode> projects, RelDataType rowType) Deprecated.
protected	Project(RelOptCluster cluster, RelTraitSet traitSet, RelNode input, List<? extends RexNode> projects, RelDataType rowType, int flags) Deprecated.

Method Summary

Modifier and Type	Method and Description
RelNode	accept(RexShuttle shuttle) Accepts a visit from a shuttle.
@Nullable RelOptCost	computeSelfCost(RelOptPlanner planner, RelMetadataQuery mq) Returns the cost of this plan (not including children).
boolean	containsOver() Returns whether this Project contains any windowed-aggregate functions.
RelNode	copy(RelTraitSet traitSet, List<RelNode> inputs) Creates a copy of this relational expression, perhaps changing traits and inputs.
abstract Project	copy(RelTraitSet traitSet, RelNode input, List<RexNode> projects, RelDataType rowType) Copies a project.
Project	copy(RelTraitSet traitSet, RelNode input, List<RexNode> projects, RelDataType rowType, int flags) Deprecated.
protected boolean	deepEquals0(@Nullable Object obj)
protected int	deepHashCode0()
RelWriter	explainTerms(RelWriter pw) Describes the inputs and attributes of this relational expression.
int	getFlags() Deprecated.
com.google.common.collect.ImmutableList<RelHint>	getHints() Returns the hints of this relational expressions as an immutable list.
Mappings.TargetMapping	getMapping() Returns a mapping, or null if this projection is not a mapping.
static Mappings.TargetMapping	getMapping(int inputFieldCount, List<? extends RexNode> projects) Returns a mapping of a set of project expressions.
List<Pair<RexNode,String>>	getNamedProjects() Returns a list of (expression, name) pairs.
static Mappings.TargetMapping	getPartialMapping(int inputFieldCount, List<? extends RexNode> projects) Returns a partial mapping of a set of project expressions.
@Nullable Permutation	getPermutation() Returns a permutation, if this projection is merely a permutation of its input fields; otherwise null.
static @Nullable Permutation	getPermutation(int inputFieldCount, List<? extends RexNode> projects) Returns a permutation, if this projection is merely a permutation of its input fields; otherwise null.
List<RexNode>	getProjects() Returns the project expressions.
boolean	isBoxed() Deprecated.
boolean	isMapping() Checks whether this is a functional mapping.
boolean	isValid(Litmus litmus, @Nullable RelNode.Context context) Returns whether this relational expression is valid.

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

childrenAccept, deriveRowType, estimateRowCount, getInput, getInputs, replaceInput

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

accept, collectVariablesSet, collectVariablesUsed, deepEquals, deepHashCode, equals, explain, getCluster, getConvention, getCorrelVariable, getDescription, getDigest, getExpectedInputRowType, getId, getInput, getRelDigest, getRelTypeName, getRowType, getTable, getTraitSet, getVariablesSet, hashCode, isEnforcer, 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.hint.Hintable

attachHints, withHints

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

explain, fieldIsNullable

Field Detail

exps

protected final com.google.common.collect.ImmutableList<RexNode> exps

hints

protected final com.google.common.collect.ImmutableList<RelHint> hints

Constructor Detail

Project

protected Project(RelOptCluster cluster,
                  RelTraitSet traits,
                  List<RelHint> hints,
                  RelNode input,
                  List<? extends RexNode> projects,
                  RelDataType rowType)

Creates a Project.

Parameters:

cluster - Cluster that this relational expression belongs to

traits - Traits of this relational expression

hints - Hints of this relation expression

input - Input relational expression

projects - List of expressions for the input columns

rowType - Output row type

Project

@Deprecated
protected Project(RelOptCluster cluster,
                              RelTraitSet traits,
                              RelNode input,
                              List<? extends RexNode> projects,
                              RelDataType rowType)

Deprecated.

Project

@Deprecated
protected Project(RelOptCluster cluster,
                              RelTraitSet traitSet,
                              RelNode input,
                              List<? extends RexNode> projects,
                              RelDataType rowType,
                              int flags)

Deprecated.

Project

protected Project(RelInput input)

Creates a Project 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 abstract Project copy(RelTraitSet traitSet,
                             RelNode input,
                             List<RexNode> projects,
                             RelDataType rowType)

Copies a project.

Parameters:

traitSet - Traits

input - Input

projects - Project expressions

rowType - Output row type

Returns:

New Project if any parameter differs from the value of this Project, or just this if all the parameters are the same

See Also:

copy(RelTraitSet, List)

copy

@Deprecated
public Project copy(RelTraitSet traitSet,
                                RelNode input,
                                List<RexNode> projects,
                                RelDataType rowType,
                                int flags)

Deprecated.

isBoxed

@Deprecated
public boolean isBoxed()

Deprecated.

accept

public RelNode accept(RexShuttle shuttle)

Description copied from interface: RelNode

Accepts a visit from a shuttle. If the shuttle updates expression, then a copy of the relation should be created. This new relation might have a different row-type.

Specified by:

accept in interface RelNode

Overrides:

accept in class AbstractRelNode

Parameters:

shuttle - Shuttle

Returns:

A copy of this node incorporating changes made by the shuttle to this node's children

getProjects

public List<RexNode> getProjects()

Returns the project expressions.

Returns:

Project expressions

getNamedProjects

public final List<Pair<RexNode,String>> getNamedProjects()

Returns a list of (expression, name) pairs. Convenient for various transformations.

Returns:

List of (expression, name) pairs

getHints

public com.google.common.collect.ImmutableList<RelHint> getHints()

Description copied from interface: Hintable

Returns the hints of this relational expressions as an immutable list.

Specified by:

getHints in interface Hintable

getFlags

@Deprecated
public int getFlags()

Deprecated.

containsOver

public final boolean containsOver()

Returns whether this Project contains any windowed-aggregate functions.

isValid

public boolean isValid(Litmus litmus,
                       @Nullable RelNode.Context context)

Description copied from interface: RelNode

Returns whether this relational expression is valid.

If assertions are enabled, this method is typically called with litmus = THROW, as follows:

assert rel.isValid(Litmus.THROW)

This signals that the method can throw an AssertionError if it is not valid.

Specified by:

isValid in interface RelNode

Overrides:

isValid in class AbstractRelNode

Parameters:

litmus - What to do if invalid

context - Context for validity checking

Returns:

Whether relational expression is valid

computeSelfCost

public @Nullable RelOptCost computeSelfCost(RelOptPlanner planner,
                                            RelMetadataQuery mq)

Description copied from interface: RelNode

Returns the cost of this plan (not including children). The base implementation throws an error; derived classes should override.

NOTE jvs 29-Mar-2006: Don't call this method directly. Instead, use RelMetadataQuery.getNonCumulativeCost(org.apache.calcite.rel.RelNode), which gives plugins a chance to override the rel's default ideas about cost.

Specified by:

computeSelfCost in interface RelNode

Overrides:

computeSelfCost in class AbstractRelNode

Parameters:

planner - Planner for cost calculation

mq - Metadata query

Returns:

Cost of this plan (not including children)

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

deepEquals0

@API(since="1.24",
     status=INTERNAL)
 @EnsuresNonNullIf(expression="#1",
                  result=true)
protected boolean deepEquals0(@Nullable Object obj)

deepHashCode0

@API(since="1.24",
     status=INTERNAL)
protected int deepHashCode0()

getMapping

public Mappings.TargetMapping getMapping()

Returns a mapping, or null if this projection is not a mapping.

Returns:

Mapping, or null if this projection is not a mapping

getMapping

public static Mappings.TargetMapping getMapping(int inputFieldCount,
                                                List<? extends RexNode> projects)

Returns a mapping of a set of project expressions.

The mapping is an inverse surjection. Every target has a source field, but no source has more than one target. Thus you can safely call Mappings.TargetMapping.getSourceOpt(int).

Parameters:

inputFieldCount - Number of input fields

projects - Project expressions

Returns:

Mapping of a set of project expressions, or null if projection is not a mapping

getPartialMapping

public static Mappings.TargetMapping getPartialMapping(int inputFieldCount,
                                                       List<? extends RexNode> projects)

Returns a partial mapping of a set of project expressions.

The mapping is an inverse function. Every target has a source field, but a source might have 0, 1 or more targets. Project expressions that do not consist of a mapping are ignored.

Parameters:

inputFieldCount - Number of input fields

projects - Project expressions

Returns:

Mapping of a set of project expressions, never null

getPermutation

public @Nullable Permutation getPermutation()

Returns a permutation, if this projection is merely a permutation of its input fields; otherwise null.

Returns:

Permutation, if this projection is merely a permutation of its input fields; otherwise null

getPermutation

public static @Nullable Permutation getPermutation(int inputFieldCount,
                                                   List<? extends RexNode> projects)

Returns a permutation, if this projection is merely a permutation of its input fields; otherwise null.

isMapping

public boolean isMapping()

Checks whether this is a functional mapping. Every output is a source field, but a source field may appear as zero, one, or more output fields.