public static String addVisibilitySuffix(String baseOrDeltaDir, long visibilityTxnId) {
    if(visibilityTxnId == 0) {
      return baseOrDeltaDir;
    }
    return baseOrDeltaDir + VISIBILITY_PREFIX
        + String.format(DELTA_DIGITS, visibilityTxnId);
  }
Since Hive 4.0, compactor produces directories with {@link #VISIBILITY_PATTERN} suffix.
_v0 is equivalent to no suffix, for backwards compatibility.
ql/src/java/org/apache/hadoop/hive/ql/io/AcidUtils.java