net.sf.farrago.namespace.ftrs
Class FtrsRemoveRedundantSortRule

java.lang.Object
  org.eigenbase.relopt.RelOptRule
      net.sf.farrago.namespace.ftrs.FtrsRemoveRedundantSortRule

 class FtrsRemoveRedundantSortRule
extends RelOptRule

FtrsRemoveRedundantSortRule removes instances of SortRel which are already satisfied by the physical ordering produced by an underlying FtrsIndexScanRel.

Version:

$Id: //open/dev/farrago/src/net/sf/farrago/namespace/ftrs/FtrsRemoveRedundantSortRule.java#17 $

Author:

John V. Sichi

Field Summary

static FtrsRemoveRedundantSortRule

instance

Fields inherited from class org.eigenbase.relopt.RelOptRule

ANY, description, operands

Constructor Summary

private

FtrsRemoveRedundantSortRule() Creates a FtrsRemoveRedundantSortRule.

Method Summary

CallingConvention	getOutConvention() Returns the calling convention of the result of firing this rule, null if not known.
void	onMatch(RelOptRuleCall call) Receives notification about a rule match.

Methods inherited from class org.eigenbase.relopt.RelOptRule

convert, equals, equals, getOperand, getOperands, 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 FtrsRemoveRedundantSortRule instance

Constructor Detail

FtrsRemoveRedundantSortRule

private FtrsRemoveRedundantSortRule()

Creates a FtrsRemoveRedundantSortRule.

Method Detail

getOutConvention

public CallingConvention getOutConvention()

Description copied from class: RelOptRule

Returns the calling convention of the result of firing this rule, null if not known.

Overrides:

getOutConvention in class RelOptRule

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)