private static Path createBucketFile(Path subdir, int bucket, Integer attemptId, boolean isAcidSchema) {
    if(isAcidSchema) {
      String fileName = BUCKET_PREFIX + String.format(BUCKET_DIGITS, bucket);
      if (attemptId != null) {
        fileName = fileName + "_" + attemptId;
      }
      return new Path(subdir, fileName);
    }
    else {
      return new Path(subdir,
        String.format(BUCKET_DIGITS, bucket));
    }
  }
Create acid or original bucket name
@param subdir the subdirectory for the bucket.
@param bucket the bucket number
@return the filename
ql/src/java/org/apache/hadoop/hive/ql/io/AcidUtils.java