private boolean filterExists(ReduceSinkOperator target, ExprNodeDesc replaced) {
      Operator<?> operator = target.getParentOperators().get(0);
      for (; operator instanceof FilterOperator; operator = operator.getParentOperators().get(0)) {
        ExprNodeDesc predicate = ((FilterOperator) operator).getConf().getPredicate();
        if (ExprNodeDescUtils.containsPredicate(predicate, replaced)) {
          return true;
        }
      }
      return false;
    }
propagates filters to other aliases based on join condition
ql/src/java/org/apache/hadoop/hive/ql/ppd/PredicateTransitivePropagate.java