static RecordIdentifier[] parseKeyIndex(OrcTail orcTail) {
    for(OrcProto.UserMetadataItem item: orcTail.getFooter().getMetadataList()) {
      if (item.hasName() && item.getName().equals(OrcRecordUpdater.ACID_KEY_INDEX_NAME)) {
        return parseKeyIndex(item.getValue().asReadOnlyByteBuffer().duplicate());
      }
    }
    return null;
  }
make sure bucketProperty in the delete event is from the {@link row} rather than whatever
{@link this#bucket} is.  For bucketed tables, the 2 must agree on bucketId encoded in it
not for necessarily the whole value.  For unbucketed tables there is no relationship.
ql/src/java/org/apache/hadoop/hive/ql/io/orc/OrcRecordUpdater.java