@Override
    public Object process(Node nd, Stack<Node> stack, NodeProcessorCtx procCtx,
        Object... nodeOutputs) throws SemanticException {
      Object o = super.process(nd, stack, procCtx, nodeOutputs);
      OpWalkerInfo owi = (OpWalkerInfo) procCtx;
      if (HiveConf.getBoolVar(owi.getParseContext().getConf(),
          HiveConf.ConfVars.HIVE_PPD_REMOVE_DUPLICATE_FILTERS)) {
        // The lateral view join is allowed to have a filter pushed through it.
        // We need to remove the filter candidate here once it has been applied.
        // If we do not remove it here, the candidates will be cleared out through
        // the getCandidateFilterOps().clear() method in another processor and the
        // filter candidate would not be removed.
        removeAllCandidates(owi);
      }
      return o;
    }
Processor for Script Operator Prevents any predicates being pushed.
ql/src/java/org/apache/hadoop/hive/ql/ppd/OpProcFactory.java