anchor.diff:  do_read(_TD = #{type := leveldb_tda,
   		tda := Tda}, ShardTab, Key, DBKey) ->
       enterdb_ldb_tda:read(ShardTab, Tda, Key, DBKey);
  +do_read(_TD = #{type := rocksdb}, ShardTab, _Key, DBKey) ->
  +    enterdb_rdb_worker:read(ShardTab, DBKey);
   do_read(_TD = #{type := Type}, _ShardTab, _Key, _DBKey) ->
       {error, {"read_not_supported", Type}};
   do_read({error, R}, _, _, _) ->
  
positive.code:     enterdb_ldb_worker:update(Shard, DBKey, Op, DataModel, Mapper, Dist);
  do_update(_TD = #{type := mem_leveldb}, _Tab, _Key, _DBKey, _Op) ->
      ok;
  do_update({error, R}, _, _Key, _DBKey, _Op) ->
      {error, R};
  do_update(TD, Tab, Key, _DBKey, _Op) ->
  
negative.code:     enterdb_ldb_worker:write(ShardTab, DBKey, DBColumns);
  do_write(#{type := mem_leveldb}, _Tab, _Key, _DBKey, _DBColumns) ->
      ok;
  do_write(#{type := rocksdb}, ShardTab, _Key, DBKey, DBColumns) ->
      enterdb_rdb_worker:write(ShardTab, DBKey, DBColumns);
  do_write({error, R}, _, _Key, _DBKey, _DBColumns) ->
      {error, R};
  do_write(TD, Tab, Key, _DBKey, _DBColumns) ->
  