Package org.apache.calcite.plan

Class RelOptRuleCall

java.lang.Object

org.apache.calcite.plan.RelOptRuleCall

Direct Known Subclasses:

HepRuleCall, VolcanoRuleCall

public abstract class RelOptRuleCall
extends java.lang.Object

A RelOptRuleCall is an invocation of a RelOptRule with a set of relational expressions as arguments.

Field Summary

Fields

Modifier and Type	Field	Description
int	id
protected static org.slf4j.Logger	LOGGER
private static int	nextId	Generator for id values.
protected java.util.Map<RelNode,java.util.List<RelNode>>	nodeInputs
protected RelOptRuleOperand	operand0
private java.util.List<RelNode>	parents
private RelOptPlanner	planner
RelNode[]	rels
RelOptRule	rule

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	RelOptRuleCall(RelOptPlanner planner, RelOptRuleOperand operand, RelNode[] rels, java.util.Map<RelNode,java.util.List<RelNode>> nodeInputs)
protected	RelOptRuleCall(RelOptPlanner planner, RelOptRuleOperand operand, RelNode[] rels, java.util.Map<RelNode,java.util.List<RelNode>> nodeInputs, java.util.List<RelNode> parents)	Creates a RelOptRuleCall.

Method Summary

Modifier and Type	Method	Description
RelBuilder	builder()	Creates a RelBuilder to be used by code within the call.
java.util.List<RelNode>	getChildRels(RelNode rel)	Returns the children of a given relational expression node matched in a rule.
RelMetadataQuery	getMetadataQuery()	Returns the current RelMetadataQuery, to be used for instance by RelOptRule.onMatch(RelOptRuleCall).
RelOptRuleOperand	getOperand0()	Returns the root operand matched by this rule.
java.util.List<RelNode>	getParents()
RelOptPlanner	getPlanner()	Returns the planner.
java.util.List<RelNode>	getRelList()	Returns a list of matched relational expressions.
RelNode[]	getRels()	Deprecated. Use getRelList() or rel(int)
RelOptRule	getRule()	Returns the invoked planner rule.
<T extends RelNode> T	rel(int ordinal)	Retrieves the ordinalth matched relational expression.
protected void	setChildRels(RelNode rel, java.util.List<RelNode> inputs)	Assigns the input relational expressions of a given relational expression, as seen by this particular call.
void	transformTo(RelNode rel)	Registers that a rule has produced an equivalent relational expression, but no other equivalences.
abstract void	transformTo(RelNode rel, java.util.Map<RelNode,RelNode> equiv)	Registers that a rule has produced an equivalent relational expression.

Methods inherited from class java.lang.Object

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

Field Detail

LOGGER

protected static final org.slf4j.Logger LOGGER

nextId

private static int nextId

Generator for id values.

id

public final int id

operand0

protected final RelOptRuleOperand operand0

nodeInputs

protected java.util.Map<RelNode,java.util.List<RelNode>> nodeInputs

rule

public final RelOptRule rule

rels

public final RelNode[] rels

planner

private final RelOptPlanner planner

parents

private final java.util.List<RelNode> parents

Constructor Detail

RelOptRuleCall

protected RelOptRuleCall(RelOptPlanner planner,
                         RelOptRuleOperand operand,
                         RelNode[] rels,
                         java.util.Map<RelNode,java.util.List<RelNode>> nodeInputs,
                         java.util.List<RelNode> parents)

Creates a RelOptRuleCall.

Parameters:

planner - Planner

operand - Root operand

rels - Array of relational expressions which matched each operand

nodeInputs - For each node which matched with matchAnyChildren=true, a list of the node's inputs

parents - list of parent RelNodes corresponding to the first relational expression in the array argument, if known; otherwise, null

RelOptRuleCall

protected RelOptRuleCall(RelOptPlanner planner,
                         RelOptRuleOperand operand,
                         RelNode[] rels,
                         java.util.Map<RelNode,java.util.List<RelNode>> nodeInputs)

Method Detail

getOperand0

public RelOptRuleOperand getOperand0()

Returns the root operand matched by this rule.

Returns:

root operand

getRule

public RelOptRule getRule()

Returns the invoked planner rule.

Returns:

planner rule

getRels

@Deprecated
public RelNode[] getRels()

Deprecated.

Use getRelList() or rel(int)

Returns a list of matched relational expressions.

Returns:

matched relational expressions

getRelList

public java.util.List<RelNode> getRelList()

Returns a list of matched relational expressions.

Returns:

matched relational expressions

See Also:

rel(int)

rel

public <T extends RelNode> T rel(int ordinal)

Retrieves the ordinalth matched relational expression. This corresponds to the ordinalth operand of the rule.

Type Parameters:

T - Type

Parameters:

ordinal - Ordinal

Returns:

Relational expression

getChildRels

public java.util.List<RelNode> getChildRels(RelNode rel)

Returns the children of a given relational expression node matched in a rule.

If the policy of the operand which caused the match is not RelOptRuleOperandChildPolicy.ANY, the children will have their own operands and therefore be easily available in the array returned by the getRelList() method, so this method returns null.

This method is for RelOptRuleOperandChildPolicy.ANY, which is generally used when a node can have a variable number of children, and hence where the matched children are not retrievable by any other means.

Parameters:

rel - Relational expression

Returns:

Children of relational expression

setChildRels

protected void setChildRels(RelNode rel,
                            java.util.List<RelNode> inputs)

Assigns the input relational expressions of a given relational expression, as seen by this particular call. Is only called when the operand is RelOptRule.any().

getPlanner

public RelOptPlanner getPlanner()

Returns the planner.

Returns:

planner

getMetadataQuery

public RelMetadataQuery getMetadataQuery()

Returns the current RelMetadataQuery, to be used for instance by RelOptRule.onMatch(RelOptRuleCall).

getParents

public java.util.List<RelNode> getParents()

Returns:

list of parents of the first relational expression

transformTo

public abstract void transformTo(RelNode rel,
                                 java.util.Map<RelNode,RelNode> equiv)

Registers that a rule has produced an equivalent relational expression.

Called by the rule whenever it finds a match. The implementation of this method guarantees that the original relational expression (that is, this.rels[0]) has its traits propagated to the new relational expression (rel) and its unregistered children. Any trait not specifically set in the RelTraitSet returned by rel.getTraits() will be copied from this.rels[0].getTraitSet().

Parameters:

rel - Relational expression equivalent to the root relational expression of the rule call, call.rels(0)

equiv - Map of other equivalences

transformTo

public final void transformTo(RelNode rel)

Registers that a rule has produced an equivalent relational expression, but no other equivalences.

Parameters:

rel - Relational expression equivalent to the root relational expression of the rule call, call.rels(0)

builder

public RelBuilder builder()

Creates a RelBuilder to be used by code within the call. The RelOptRule.relBuilderFactory argument contains policies such as what implementation of Filter to create.