net.sf.farrago.fennel.rel
Class FennelRenameRule

java.lang.Object
  org.eigenbase.relopt.RelOptRule
      net.sf.farrago.fennel.rel.FennelRenameRule

Direct Known Subclasses:

FennelInsertRenameRule

public class FennelRenameRule
extends RelOptRule

FennelRenameRule is a rule for converting a rename-only Project into FennelRename.

Version:

$Id: //open/dev/farrago/src/net/sf/farrago/fennel/rel/FennelRenameRule.java#4 $

Author:

John V. Sichi

Field Summary

static FennelRenameRule

instance

Fields inherited from class org.eigenbase.relopt.RelOptRule

ANY, description, operands

Constructor Summary

private	FennelRenameRule() Creates a FennelRenameRule.
protected	FennelRenameRule(RelOptRuleOperand operand) Creates a FennelRenameRule with an explicit root operand.

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.
protected FennelRenameRel	renameChild(ProjectRel project) If appropriate, creates a FennelRenameRel to replace an existing ProjectRel.

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 FennelRenameRule instance

Constructor Detail

FennelRenameRule

private FennelRenameRule()

Creates a FennelRenameRule.

FennelRenameRule

protected FennelRenameRule(RelOptRuleOperand operand)

Creates a FennelRenameRule with an explicit root operand.

Parameters:

operand - root operand, must not be null

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)

renameChild

protected FennelRenameRel renameChild(ProjectRel project)

If appropriate, creates a FennelRenameRel to replace an existing ProjectRel.

Parameters:

project - the existing ProjectRel

Returns:

the replacement FennelRenameRel or null if the project cannot be replaced with a FennelRenameRel