protected RelOptPlanner createTapPlanner()
{
final VolcanoPlanner planner = new VolcanoPlanner();
planner.addRelTraitDef( Cascading.CONVENTION.getTraitDef() );
planner.addRelTraitDef( ConventionTraitDef.instance );
planner.addRule( TableAccessRule.instance );
planner.addRule( JavaRules.ENUMERABLE_CALC_RULE );
planner.addRule( ProjectToCalcRule.instance );
planner.addRule( EnumerableTapRule.INSTANCE );
planner.setLocked( true ); // prevent further rules being added
return planner;