currentPlan = new PhysicalPlan();
// PlanWalker childWalker = currentWalker
// .spawnChildWalker(filter.getFilterPlan());
PlanWalker childWalker = new ReverseDependencyOrderWalkerWOSeenChk(loSplitOutput.getFilterPlan());
pushWalker(childWalker);
//currentWalker.walk(this);
currentWalker.walk(
new ExpToPhyTranslationVisitor( currentWalker.getPlan(),
childWalker, loSplitOutput, currentPlan, logToPhyMap) );