org.apache.calcite.plan

Class RelOptRuleCall

java.lang.Object

org.apache.calcite.plan.RelOptRuleCall

Direct Known Subclasses:

HepRuleCall, VolcanoRuleCall

public abstract class RelOptRuleCall
extends Object

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

Field Summary

Fields

Modifier and Type	Field and Description
int	id
protected static Logger	LOGGER
RelNode[]	rels
RelOptRule	rule

Constructor Summary

Constructors

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

Method Summary

Methods

Modifier and Type	Method and Description
List<RelNode>	getChildRels(RelNode rel) Returns the children of a given relational expression node matched in a rule.
RelOptRuleOperand	getOperand0() Returns the root operand matched by this rule.
List<RelNode>	getParents()
RelOptPlanner	getPlanner() Returns the planner.
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.
void	transformTo(RelNode rel) Registers that a rule has produced an equivalent relational expression, but no other equivalences.
abstract void	transformTo(RelNode rel, 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 Logger LOGGER

id

public final int id

rule

public final RelOptRule rule

rels

public final RelNode[] rels

Constructor Detail

RelOptRuleCall

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

public RelNode[] getRels()

Deprecated. Use getRelList() or rel(int)

Returns a list of matched relational expressions.

Returns:

matched relational expressions

getRelList

public 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 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 getRels() 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

getPlanner

public RelOptPlanner getPlanner()

Returns the planner.

Returns:

planner

getParents

public List<RelNode> getParents()

Returns:

list of parents of the first relational expression

transformTo

public abstract void transformTo(RelNode rel,
               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)