@Override
  public void configureJobConf(JobConf job) {
    if (conf.getInsertOverwrite()) {
      job.setBoolean(Utilities.ENSURE_OPERATORS_EXECUTED, true);
    }
  }
Check if nested column paths is set for 'conf'.
If set, create a copy of 'conf' with this property unset.
ql/src/java/org/apache/hadoop/hive/ql/exec/FileSinkOperator.java