Package org.apache.calcite.rel.rules

Class SampleToFilterRule

java.lang.Object

org.apache.calcite.plan.RelOptRule

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

org.apache.calcite.rel.rules.SampleToFilterRule

All Implemented Interfaces:

TransformationRule

@Enclosing
public class SampleToFilterRule
extends RelRule<SampleToFilterRule.Config>
implements TransformationRule

This rule rewrite Sample which is bernoulli to the Filter.

For example:

    select deptno from "scott".dept tablesample bernoulli(50);
 

will convert to:

    select deptno from "scott".dept where rand() < 0.5;
 

The sql:

    select deptno from "scott".dept tablesample bernoulli(50) REPEATABLE(10);
 

will convert to:

    select deptno from "scott".dept where rand(10) < 0.5;
 

See Also:

• CoreRules.SAMPLE_TO_FILTER

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	SampleToFilterRule.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 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	SampleToFilterRule(SampleToFilterRule.Config config)

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

SampleToFilterRule

protected SampleToFilterRule(SampleToFilterRule.Config config)

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)