@Override
    public Object process(Node nd, Stack<Node> stack, NodeProcessorCtx procCtx,
        Object... nodeOutputs) throws SemanticException {
      @SuppressWarnings("unchecked")
      CommonJoinOperator<JoinDesc> join = (CommonJoinOperator) nd;
      ReduceSinkOperator source = (ReduceSinkOperator) stack.get(stack.size() - 2);
      FilterOperator filter = (FilterOperator) stack.get(stack.size() - 3);
      int srcPos = join.getParentOperators().indexOf(source);

      TransitiveContext context = (TransitiveContext) procCtx;
      Map<CommonJoinOperator, int[][]> filterPropagates = context.getFilterPropagates();
      Map<ReduceSinkOperator, List<ExprNodeDesc>> newFilters = context.getNewfilters();

      int[][] targets = filterPropagates.get(join);
      if (targets == null) {
        filterPropagates.put(join, targets = getTargets(join));
      }

      List<Operator<? extends OperatorDesc>> parents = join.getParentOperators();
      for (int targetPos : targets[srcPos]) {
        ReduceSinkOperator target = (ReduceSinkOperator) parents.get(targetPos);
        List<ExprNodeDesc> sourceKeys = source.getConf().getKeyCols();
        List<ExprNodeDesc> targetKeys = target.getConf().getKeyCols();

        ExprNodeDesc predicate = filter.getConf().getPredicate();
        ExprNodeDesc replaced = ExprNodeDescUtils.replace(predicate, sourceKeys, targetKeys);
        if (replaced != null && !filterExists(target, replaced)) {
          List<ExprNodeDesc> prev = newFilters.get(target);
          if (prev == null) {
            newFilters.put(target, ExprNodeDescUtils.split(replaced));
          } else {
            ExprNodeDescUtils.split(replaced, prev);
          }
        }
      }
      return null;
    }
propagates filters to other aliases based on join condition
ql/src/java/org/apache/hadoop/hive/ql/ppd/PredicateTransitivePropagate.java