@VisibleForTesting
  public static String deleteDeltaSubdir(long min, long max, int statementId) {
    return deleteDeltaSubdir(min, max) + "_" + String.format(STATEMENT_DIGITS, statementId);
  }
Each write statement in a transaction creates its own delete delta dir,
when split-update acid operational property is turned on.
@since 2.2.x
ql/src/java/org/apache/hadoop/hive/ql/io/AcidUtils.java