net.sf.farrago.namespace.mql
Class MedMqlPushDownRule

java.lang.Object
  org.eigenbase.relopt.RelOptRule
      net.sf.farrago.namespace.mql.MedMqlPushDownRule

 class MedMqlPushDownRule
extends RelOptRule

MedMqlPushDownRule is an optimizer rule to push filters and projections down into MQL.

Version:

$Id: //open/dev/farrago/ext/mql/src/net/sf/farrago/namespace/mql/MedMqlPushDownRule.java#4 $

Author:

John Sichi

Field Summary

Fields inherited from class org.eigenbase.relopt.RelOptRule

ANY, description, operands

Constructor Summary

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

Method Summary

private RelNode	createFarragoUdxRel(MedMqlTableRel tableRel, RelDataType rowType, Map<String,String> fieldBindings)
private Map<String,String>	createFieldBindings(MedMqlTableRel tableRel)
void	onMatch(RelOptRuleCall call) Receives notification about a rule match.
private void	transformToFarragoUdxRel(RelOptRuleCall call, MedMqlTableRel tableRel, FilterRel filter, ProjectRel topProj, ProjectRel bottomProj)
private RexNode	translateFilter(FilterRel filterRel, String[] fieldNames, Map<String,String> fieldBindings)
private boolean	validProjection(String[] fieldNames)

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

MedMqlPushDownRule

public MedMqlPushDownRule(RelOptRuleOperand operand,
                          String id)

Creates a MedMqlPushDownRule.

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)

translateFilter

private RexNode translateFilter(FilterRel filterRel,
                                String[] fieldNames,
                                Map<String,String> fieldBindings)

validProjection

private boolean validProjection(String[] fieldNames)

createFieldBindings

private Map<String,String> createFieldBindings(MedMqlTableRel tableRel)

createFarragoUdxRel

private RelNode createFarragoUdxRel(MedMqlTableRel tableRel,
                                    RelDataType rowType,
                                    Map<String,String> fieldBindings)

transformToFarragoUdxRel

private void transformToFarragoUdxRel(RelOptRuleCall call,
                                      MedMqlTableRel tableRel,
                                      FilterRel filter,
                                      ProjectRel topProj,
                                      ProjectRel bottomProj)