The only way to use this feature is to specify an empty database name in Distributed table definition, but then you get a warning:

```
CREATE TABLE `demo_loan_all` (...) ENGINE=Distributed(test_cluster_two_shards_different_databases, '', demo_loan_01568, cityHash64(id));

<Warning> StorageDistributed (demo_loan_all): Name of remote database is empty. Default database will be used implicitly.
```
throw Exception(
                "Storage Distributed requires from 3 to 5 parameters - "
                "name of configuration section with list of remote servers, "
                "name of remote database, "
                "name of remote table, "
                "sharding key expression (optional), "
                "policy to store data in (optional).",
                ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
        String cluster_name = getClusterNameAndMakeLiteral(engine_args[0]);
        engine_args[1] = evaluateConstantExpressionOrIdentifierAsLiteral(engine_args[1], args.getLocalContext());
        engine_args[2] = evaluateConstantExpressionOrIdentifierAsLiteral(engine_args[2], args.getLocalContext());
        String remote_database = engine_args[1]->as<ASTLiteral &>().value.safeGet<String>();
        String remote_table = engine_args[2]->as<ASTLiteral &>().value.safeGet<String>();
        const auto & sharding_key = engine_args.size() >= 4 ? engine_args[3] : nullptr;
        const auto & storage_policy = engine_args.size() >= 5 ? engine_args[4]->as<ASTLiteral &>().value.safeGet<String>() : "default";
        
        if (sharding_key)
        {
            auto sharding_expr = buildShardingKeyExpression(sharding_key, args.getContext(), args.columns.getAllPhysical(), true);
            const Block & block = sharding_expr->getSampleBlock();
            if (block.columns() != 1)
                throw Exception("Sharding expression must return exactly one column", ErrorCodes::INCORRECT_NUMBER_OF_COLUMNS);
            auto type = block.getByPosition(0).type;
            if (!type->isValueRepresentedByInteger())
                throw Exception("Sharding expression has type " + type->getName() +
                    ", but should be one of integer type", ErrorCodes::TYPE_MISMATCH);
        }
        
        DistributedSettings distributed_settings;
        if (args.storage_def->settings)