Package org.apache.calcite.piglet

Class PigToSqlAggregateRule

java.lang.Object

org.apache.calcite.plan.RelOptRule

org.apache.calcite.plan.RelRule<PigToSqlAggregateRule.Config>

org.apache.calcite.piglet.PigToSqlAggregateRule

@Enclosing
public class PigToSqlAggregateRule
extends RelRule<PigToSqlAggregateRule.Config>

Planner rule that converts Pig aggregate UDF calls to built-in SQL aggregates.

This rule is applied for logical relational algebra plan that is the result of Pig translation. In Pig, aggregate calls are separate from grouping where we create a bag of all tuples in each group first then apply the Pig aggregate UDF later. It is inefficient to do that in SQL.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	PigToSqlAggregateRule.Config	Rule configuration.

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

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

Modifier and Type	Field	Description
static final PigToSqlAggregateRule	INSTANCE

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	PigToSqlAggregateRule(PigToSqlAggregateRule.Config config)	Creates a PigToSqlAggregateRule.

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

Field Details

INSTANCE

public static final PigToSqlAggregateRule INSTANCE

Constructor Details

PigToSqlAggregateRule

protected PigToSqlAggregateRule(PigToSqlAggregateRule.Config config)

Creates a PigToSqlAggregateRule.

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)