@Override
  public void setWriteId(long writeId) {
    // We don't actually need the write id, but by implementing DDLDescWithWriteId it ensures that it is allocated
  }
DDL task description for ALTER TABLE ... PARTITION COLUMN ... commands.
ql/src/java/org/apache/hadoop/hive/ql/ddl/table/partition/alter/AlterTableAlterPartitionDesc.java