@Override
    public R put(T key, R value) {
        checkClosed();
        lazyGetRocksDb().put(ROCKSDB_COL_FAMILY, key, value);
        return value;
    }
This class provides a disk spillable only kv buffer implementation.
All of the data is stored using the RocksDB implementation.
inlong-sort/sort-flink/sort-flink-v1.13/sort-connectors/iceberg/src/main/java/org/apache/inlong/sort/iceberg/sink/collections/RocksDBKVBuffer.java