org.eigenbase.rel.rules
Class PushProjectPastFilterRule

java.lang.Object
  org.eigenbase.relopt.RelOptRule
      org.eigenbase.rel.rules.PushProjectPastFilterRule

public class PushProjectPastFilterRule
extends RelOptRule

PushProjectPastFilterRule implements the rule for pushing a projection past a filter.

Version:

$Id: //open/dev/farrago/src/org/eigenbase/rel/rules/PushProjectPastFilterRule.java#15 $

Author:

Zelaine Fong

Field Summary

static PushProjectPastFilterRule	instance
private PushProjector.ExprCondition	preserveExprCondition Expressions that should be preserved in the projection

Fields inherited from class org.eigenbase.relopt.RelOptRule

ANY, description, operands

Constructor Summary

private	PushProjectPastFilterRule() Creates a PushProjectPastFilterRule.
	PushProjectPastFilterRule(RelOptRuleOperand operand, PushProjector.ExprCondition preserveExprCondition, String id) Creates a PushProjectPastFilterRule with an explicit root operand and condition to preserve operands.

Method Summary

void	onMatch(RelOptRuleCall call) Receives notification about a rule match.

Methods inherited from class org.eigenbase.relopt.RelOptRule

convert, equals, equals, getOperand, getOperands, getOutConvention, getOutTrait, hashCode, matches, mergeTraitsAndConvert, mergeTraitsAndConvert, toString

Methods inherited from class java.lang.Object

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

Field Detail

instance

public static final PushProjectPastFilterRule instance

preserveExprCondition

private final PushProjector.ExprCondition preserveExprCondition

Expressions that should be preserved in the projection

Constructor Detail

PushProjectPastFilterRule

private PushProjectPastFilterRule()

Creates a PushProjectPastFilterRule.

PushProjectPastFilterRule

public PushProjectPastFilterRule(RelOptRuleOperand operand,
                                 PushProjector.ExprCondition preserveExprCondition,
                                 String id)

Creates a PushProjectPastFilterRule with an explicit root operand and condition to preserve operands.

Parameters:

operand - root operand, must not be null

id - Part of description

Method Detail

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.eigenbase.rel.RelNode) to register the expression.

Specified by:

onMatch in class RelOptRule

Parameters:

call - Rule call

See Also:

RelOptRule.matches(RelOptRuleCall)