public void merge(RowData joinKey, byte[] uniqueKeyBytes) throws IOException {
    byte[] joinKeyBytes = serializeKey(joinKey);
    byte[] joinKeyAndPrimaryKeyBytes = Bytes.mergeByte(joinKeyBytes, uniqueKeyBytes);
    ByteArrayWrapper keyWrap = wrap(joinKeyBytes);
    if (guavaCache.getIfPresent(keyWrap) != null) {
      guavaCache.invalidate(keyWrap);
    }
    rocksDB.put(columnFamilyName, 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