Package org.apache.calcite.rel.rules

Class MeasureRules.AggregateMeasure2Rule

java.lang.Object

org.apache.calcite.plan.RelOptRule

org.apache.calcite.plan.RelRule<MeasureRules.AggregateMeasure2RuleConfig>

org.apache.calcite.rel.rules.MeasureRules.AggregateMeasure2Rule

All Implemented Interfaces:

TransformationRule

Enclosing class:

MeasureRules

public static class MeasureRules.AggregateMeasure2Rule
extends RelRule<MeasureRules.AggregateMeasure2RuleConfig>
implements TransformationRule

Rule that matches an Aggregate with at least one call to SqlInternalOperators.AGG_M2V and expands these calls by asking the measure for its expression.

Converts

 Aggregate(a, b, AGG_M2V(c), SUM(d), AGG_M2V(e))
   R
 

to

 Project(a, b, RexSubQuery(...), sum_d, RexSubQuery(...))
   Aggregate(a, b, SUM(d) AS sum_d)
     R
 

We will optimize those RexSubQuery later. For example,

 SELECT deptno,
     (SELECT AVG(sal)
      FROM emp
      WHERE deptno = e.deptno)
 FROM Emp
 

will become

 SELECT deptno, AVG(sal)
 FROM emp
 WHERE deptno = e.deptno
 

See Also:

• RelMdMeasure
• MeasureRules.AGGREGATE2
• MeasureRules.AggregateMeasure2RuleConfig

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.calcite.plan.RelRule

RelRule.Config, RelRule.Done, RelRule.MatchHandler<R extends RelOptRule>, RelRule.OperandBuilder, RelRule.OperandDetailBuilder<R extends RelNode>, RelRule.OperandTransform

Nested classes/interfaces inherited from class org.apache.calcite.plan.RelOptRule

RelOptRule.ConverterRelOptRuleOperand

Field Summary

Fields inherited from class org.apache.calcite.plan.RelRule

config

Fields inherited from class org.apache.calcite.plan.RelOptRule

description, operands, relBuilderFactory

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AggregateMeasure2Rule(MeasureRules.AggregateMeasure2RuleConfig config)	Creates an AggregateMeasure2Rule.

Method Summary

Modifier and Type	Method	Description
void	onMatch(RelOptRuleCall call)	Receives notification about a rule match.

Methods inherited from class org.apache.calcite.plan.RelOptRule

any, convert, convert, convert, convert, convertList, convertOperand, convertOperand, equals, equals, getOperand, getOperands, getOutConvention, getOutTrait, hashCode, matches, none, operand, operand, operand, operand, operand, operandJ, operandJ, some, toString, unordered

Methods inherited from class java.lang.Object

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

Constructor Details

AggregateMeasure2Rule

protected AggregateMeasure2Rule(MeasureRules.AggregateMeasure2RuleConfig config)

Creates an AggregateMeasure2Rule.

Method Details

onMatch

public void onMatch(RelOptRuleCall call)

Description copied from class: RelOptRule

Receives notification about a rule match. At the time that this method is called, call.rels holds the set of relational expressions which match the operands to the rule; call.rels[0] is the root expression.

Typically a rule would check that the nodes are valid matches, creates a new expression, then calls back RelOptRuleCall.transformTo(org.apache.calcite.rel.RelNode, java.util.Map<org.apache.calcite.rel.RelNode, org.apache.calcite.rel.RelNode>, org.apache.calcite.plan.RelHintsPropagator) to register the expression.

Specified by:

onMatch in class RelOptRule

Parameters:

call - Rule call

See Also:

• RelOptRule.matches(RelOptRuleCall)