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.
```
, distributed_settings(distributed_settings_)
    , rng(randomSeed())
{
    StorageInMemoryMetadata storage_metadata;
    storage_metadata.setColumns(columns_);
    storage_metadata.setConstraints(constraints_);
    setInMemoryMetadata(storage_metadata);
    if (sharding_key_)
    {
        sharding_key_expr = buildShardingKeyExpression(sharding_key_, getContext(), storage_metadata.getColumns().getAllPhysical(), false);
        sharding_key_column_name = sharding_key_->getColumnName();
        sharding_key_is_deterministic = isExpressionActionsDeterministics(sharding_key_expr);
    }
    if (!relative_data_path.empty())
    {
        storage_policy = getContext()->getStoragePolicy(storage_policy_name_);
        data_volume = storage_policy->getVolume(0);
        if (storage_policy->getVolumes().size() > 1)
            LOG_WARNING(log, "Storage policy for Distributed table has multiple volumes. "
                             "Only {} volume will be used to store data. Other will be ignored.", data_volume->getName());
    }
    
    if (!attach_ && !cluster_name.empty())
    {
        size_t num_local_shards = getContext()->getCluster(cluster_name)->getLocalShardCount();
        if (num_local_shards && remote_database == id_.database_name && remote_table == id_.table_name)
            throw Exception("Distributed table " + id_.table_name + " looks at itself", ErrorCodes::INFINITE_LOOP);
    }
}
StorageDistributed::StorageDistributed(