Package org.apache.calcite.rel.rules
Class AggregateProjectMergeRule
- java.lang.Object
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- org.apache.calcite.plan.RelOptRule
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- org.apache.calcite.rel.rules.AggregateProjectMergeRule
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public class AggregateProjectMergeRule extends RelOptRule
Planner rule that recognizes aAggregate
on top of aProject
and if possible aggregate through the project or removes the project.This is only possible when the grouping expressions and arguments to the aggregate functions are field references (i.e. not expressions).
In some cases, this rule has the effect of trimming: the aggregate will use fewer columns than the project did.
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Field Summary
Fields Modifier and Type Field Description static AggregateProjectMergeRule
INSTANCE
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Fields inherited from class org.apache.calcite.plan.RelOptRule
description, operands, relBuilderFactory
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Constructor Summary
Constructors Constructor Description AggregateProjectMergeRule(java.lang.Class<? extends Aggregate> aggregateClass, java.lang.Class<? extends Project> projectClass, RelBuilderFactory relBuilderFactory)
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description static RelNode
apply(RelOptRuleCall call, Aggregate aggregate, Project project)
void
onMatch(RelOptRuleCall call)
Receives notification about a rule match.-
Methods inherited from class org.apache.calcite.plan.RelOptRule
any, convert, convert, convertList, convertOperand, convertOperand, equals, equals, getOperand, getOperands, getOutConvention, getOutTrait, hashCode, matches, none, operand, operand, operand, operand, operand, operandJ, operandJ, some, toString, unordered
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Field Detail
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INSTANCE
public static final AggregateProjectMergeRule INSTANCE
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Constructor Detail
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AggregateProjectMergeRule
public AggregateProjectMergeRule(java.lang.Class<? extends Aggregate> aggregateClass, java.lang.Class<? extends Project> projectClass, RelBuilderFactory relBuilderFactory)
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Method Detail
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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>)
to register the expression.- Specified by:
onMatch
in classRelOptRule
- Parameters:
call
- Rule call- See Also:
RelOptRule.matches(RelOptRuleCall)
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apply
public static RelNode apply(RelOptRuleCall call, Aggregate aggregate, Project project)
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