org.apache.calcite.plan

Class RelOptRuleOperand

java.lang.Object

org.apache.calcite.plan.RelOptRuleOperand

public class RelOptRuleOperand
extends Object

Operand that determines whether a RelOptRule can be applied to a particular expression.

For example, the rule to pull a filter up from the left side of a join takes operands: Join(Filter, Any).

Note that children means different things if it is empty or it is null: Join(Filter (), Any) means that, to match the rule, Filter must have no operands.

Field Summary

Fields

Modifier and Type	Field and Description
RelOptRuleOperandChildPolicy	childPolicy Whether child operands can be matched in any order.
int	ordinalInParent
int	ordinalInRule
int[]	solveOrder

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	RelOptRuleOperand(Class<R> clazz, RelTrait trait, com.google.common.base.Predicate<? super R> predicate, RelOptRuleOperandChildren children) Creates an operand.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(Object obj)
List<RelOptRuleOperand>	getChildOperands() Returns the child operands.
Class<? extends RelNode>	getMatchedClass()
RelOptRuleOperand	getParent() Returns the parent operand.
RelOptRule	getRule() Returns the rule this operand belongs to.
int	hashCode()
boolean	matches(RelNode rel) Returns whether a relational expression matches this operand.
void	setParent(RelOptRuleOperand parent) Sets the parent operand.
void	setRule(RelOptRule rule) Sets the rule this operand belongs to

Methods inherited from class java.lang.Object

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

Field Detail

solveOrder

public int[] solveOrder

ordinalInParent

public int ordinalInParent

ordinalInRule

public int ordinalInRule

childPolicy

public final RelOptRuleOperandChildPolicy childPolicy

Whether child operands can be matched in any order.

Constructor Detail

RelOptRuleOperand

protected RelOptRuleOperand(Class<R> clazz,
                 RelTrait trait,
                 com.google.common.base.Predicate<? super R> predicate,
                 RelOptRuleOperandChildren children)

Creates an operand.

The childOperands argument is often populated by calling one of the following methods: RelOptRule.some(org.apache.calcite.plan.RelOptRuleOperand, org.apache.calcite.plan.RelOptRuleOperand...), RelOptRule.none(), RelOptRule.any(), RelOptRule.unordered(org.apache.calcite.plan.RelOptRuleOperand, org.apache.calcite.plan.RelOptRuleOperand...), See RelOptRuleOperandChildren for more details.

Parameters:

clazz - Class of relational expression to match (must not be null)

trait - Trait to match, or null to match any trait

predicate - Predicate to apply to relational expression

children - Child operands

Method Detail

getParent

public RelOptRuleOperand getParent()

Returns the parent operand.

Returns:

parent operand

setParent

public void setParent(RelOptRuleOperand parent)

Sets the parent operand.

Parameters:

parent - Parent operand

getRule

public RelOptRule getRule()

Returns the rule this operand belongs to.

Returns:

containing rule

setRule

public void setRule(RelOptRule rule)

Sets the rule this operand belongs to

Parameters:

rule - containing rule

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

getMatchedClass

public Class<? extends RelNode> getMatchedClass()

Returns:

relational expression class matched by this operand

getChildOperands

public List<RelOptRuleOperand> getChildOperands()

Returns the child operands.

Returns:

child operands

matches

public boolean matches(RelNode rel)

Returns whether a relational expression matches this operand. It must be of the right class and trait.