public void batchWrite(RowData joinKey, byte[] uniqueKeyBytes) throws IOException {
    byte[] joinKeyBytes = serializeKey(joinKey);
    byte[] joinKeyAndPrimaryKeyBytes = Bytes.mergeByte(joinKeyBytes, uniqueKeyBytes);
    LookupRecord.OpType opType = convertToOpType(joinKey.getRowKind());
    lookupRecordsQueue.add(LookupRecord.of(opType, joinKeyAndPrimaryKeyBytes, EMPTY));
  }
Merge key and element into guava cache and rocksdb.
amoro-format-mixed/amoro-mixed-flink/amoro-mixed-flink-common/src/main/java/org/apache/amoro/flink/lookup/RocksDBSetState.java