private static ColumnFamilyOptions createColumnFamilyOptions(final String groupId) {
        final BlockBasedTableConfig tConfig = StorageOptionsFactory.getRocksDBTableFormatConfig(groupId,
            RocksRawKVStore.class);
        return StorageOptionsFactory.getRocksDBColumnFamilyOptions(groupId, RocksRawKVStore.class) //
            .setTableFormatConfig(tConfig) //
            .setMergeOperator(new StringAppendOperator());
    }
Local KV store based on RocksDB

@author dennis
@author jiachun.fjc
jraft-rheakv/rheakv-core/src/main/java/com/alipay/sofa/jraft/rhea/storage/RocksRawKVStore.java