@Override
    public String toString() {
      return "SharedResult { " + this.retainableOps + "; " + this.discardableOps + "; "
          + this.discardableInputOps + "};";
    }
Orders TS operators in decreasing order by "weight".
ql/src/java/org/apache/hadoop/hive/ql/optimizer/SharedWorkOptimizer.java