@Override
    public String toString() {
      StringBuilder str = new StringBuilder();
      if (isSplitUpdate()) {
        str.append("|" + SPLIT_UPDATE_STRING);
      }
      if (isHashBasedMerge()) {
        str.append("|" + HASH_BASED_MERGE_STRING);
      }
      if (isInsertOnly()) {
        str.append("|" + INSERT_ONLY_STRING);
      }
      if (isFetchBucketId()) {
        str.append("|" + INSERT_ONLY_FETCH_BUCKET_ID_STRING);
      }
      if (isFetchBucketId()) {
        str.append("|" + FETCH_DELETED_ROWS_STRING);
      }
      return str.toString();
    }
Sets the hash-based merge property for ACID operations that combines delta files using
GRACE hash join based approach, when turned on. (Currently unimplemented!)
@param isHashBasedMerge a boolean property that turns on hash-based merge when true.
@return the acidOperationalProperties object.
ql/src/java/org/apache/hadoop/hive/ql/io/AcidUtils.java