net.sf.farrago.namespace.jdbc
Class MedJdbcPushDownRule

java.lang.Object
  org.eigenbase.relopt.RelOptRule
      net.sf.farrago.namespace.jdbc.MedJdbcPushDownRule

 class MedJdbcPushDownRule
extends RelOptRule

MedJdbcPushDownRule is a rule to push filters and projections down to Jdbc sources.

Version:

$Id: //open/dev/farrago/src/net/sf/farrago/namespace/jdbc/MedJdbcPushDownRule.java#16 $

Author:

Sunny Choi

Field Summary

Fields inherited from class org.eigenbase.relopt.RelOptRule

ANY, description, operands

Constructor Summary

MedJdbcPushDownRule(RelOptRuleOperand operand, String id)
Creates a MedJdbcPushDownRule.

Method Summary

private String	getSourceFieldName(MedJdbcQueryRel queryRel, String name)
private boolean	isPermutation(ProjectRel projectRel)
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

Constructor Detail

MedJdbcPushDownRule

public MedJdbcPushDownRule(RelOptRuleOperand operand,
                           String id)

Creates a MedJdbcPushDownRule.

Parameters:

operand - Root operand, must not be null

id - Description of rule

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)

isPermutation

private boolean isPermutation(ProjectRel projectRel)

getSourceFieldName

private String getSourceFieldName(MedJdbcQueryRel queryRel,
                                  String name)