default List<FieldSchema> sortColumns(org.apache.hadoop.hive.ql.metadata.Table table) {
    Preconditions.checkState(supportsSortColumns(), "Should only be called for table formats where data sorting " +
        "is supported");
    return Collections.emptyList();
  }
Collect the columns that are used to sort the content of the data files
@param table the table which is being sorted
@return the list of columns that are used during data sorting
ql/src/java/org/apache/hadoop/hive/ql/metadata/HiveStorageHandler.java