Package org.apache.calcite.adapter.file

Class CsvProjectTableScanRule

java.lang.Object

org.apache.calcite.plan.RelOptRule

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

org.apache.calcite.adapter.file.CsvProjectTableScanRule

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

Planner rule that projects from a CsvTableScan scan just the columns needed to satisfy a projection. If the projection's expressions are trivial, the projection is removed.

See Also:

• FileRules.PROJECT_SCAN

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	CsvProjectTableScanRule.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	CsvProjectTableScanRule(CsvProjectTableScanRule.Config config)	Creates a CsvProjectTableScanRule.

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

CsvProjectTableScanRule

protected CsvProjectTableScanRule(CsvProjectTableScanRule.Config config)

Creates a CsvProjectTableScanRule.

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)