@Explain(displayName = "columns", explainLevels = { Level.USER, Level.DEFAULT, Level.EXTENDED })
    public List<FieldSchema> getCols() {
      return columns;
    }
@return location of partition in relation to table
ql/src/java/org/apache/hadoop/hive/ql/ddl/table/partition/add/AlterTableAddPartitionDesc.java