org.apache.calcite.plan

Class RelOptRuleOperand

java.lang.Object

org.apache.calcite.plan.RelOptRuleOperand

Direct Known Subclasses:

RelOptRule.ConverterRelOptRuleOperand

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
@Nullable RelTrait	trait

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	RelOptRuleOperand(Class<R> clazz, RelTrait trait, Predicate<? super R> predicate, RelOptRuleOperandChildren children) Deprecated. Use RelOptRule.operand(Class, RelOptRuleOperandChildren) or one of its overloaded methods.

Method Summary

Modifier and Type	Method and Description
boolean	equals(@Nullable Object obj)
List<RelOptRuleOperand>	getChildOperands() Returns the child operands.
Class<? extends RelNode>	getMatchedClass() Returns relational expression class matched by this operand.
@Nullable 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(@Nullable RelOptRuleOperand parent) Sets the parent operand.
void	setRule(@UnknownInitialization RelOptRule rule) Sets the rule this operand belongs to.
String	toString() FOR DEBUG ONLY.

Methods inherited from class java.lang.Object

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

Field Detail

solveOrder

public int[] solveOrder

ordinalInParent

public int ordinalInParent

ordinalInRule

public int ordinalInRule

trait

public final @Nullable RelTrait trait

childPolicy

public final RelOptRuleOperandChildPolicy childPolicy

Whether child operands can be matched in any order.

Constructor Detail

RelOptRuleOperand

@Deprecated
protected RelOptRuleOperand(Class<R> clazz,
                                        RelTrait trait,
                                        Predicate<? super R> predicate,
                                        RelOptRuleOperandChildren children)

Deprecated. Use RelOptRule.operand(Class, RelOptRuleOperandChildren) or one of its overloaded methods.

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 @Nullable RelOptRuleOperand getParent()

Returns the parent operand.

Returns:

parent operand

setParent

public void setParent(@Nullable 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(@UnknownInitialization 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(@Nullable Object obj)

Overrides:

equals in class Object

toString

public String toString()

FOR DEBUG ONLY.

To facilitate IDE shows the operand description in the debugger, returns the root operand description, but highlight current operand's matched class with '*' in the description.

e.g. The following are examples of rule operand description for the operands that match with LogicalFilter.

• SemiJoinRule:project: Project(Join(*RelNode*, Aggregate))
• ProjectFilterTransposeRule: LogicalProject(*LogicalFilter*)
• FilterProjectTransposeRule: *Filter*(Project)
• ReduceExpressionsRule(Filter): *LogicalFilter*
• PruneEmptyJoin(right): Join(*RelNode*, Values)

Overrides:

toString in class Object

See Also:

describeIt(RelOptRuleOperand)

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.