@Override
    // Chooses a representative alias, index, and order to use as the String, the first is used
    // because it is set in the constructor
    public String toString() {
      return "name: " + names.get(0) + " index: " + indexes.get(0) + " order: " + sortOrder;
    }
SortCol.

An implementation of BucketSortCol which contains known aliases/indexes of equivalent columns
which data is determined to be sorted on.  Unlike aliases, and indexes the sort order is known
to be constant for all equivalent columns.
ql/src/java/org/apache/hadoop/hive/ql/optimizer/physical/BucketingSortingCtx.java