@Override
    public R remove(T key) {
        checkClosed();
        R value = get(key);
        if (value != null) {
            lazyGetRocksDb().delete(ROCKSDB_COL_FAMILY, (T) key);
        }
        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