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.
```
#include <Interpreters/evaluateConstantExpression.h>
#include <Interpreters/getClusterName.h>
#include <Interpreters/getTableExpressions.h>
#include <Functions/IFunction.h>
#include <Processors/QueryPlan/BuildQueryPipelineSettings.h>
#include <Processors/QueryPlan/Optimizations/QueryPlanOptimizationSettings.h>
#include <Processors/QueryPlan/ReadFromPreparedSource.h>
#include <Processors/Sources/NullSource.h>
#include <Processors/Sources/SourceFromInputStream.h>
#include <Processors/NullSink.h>
#include <Core/Field.h>
#include <Core/Settings.h>
#include <IO/ReadHelpers.h>
#include <IO/WriteBufferFromString.h>
#include <IO/Operators.h>
#include <IO/ConnectionTimeoutsContext.h>
#include <Poco/DirectoryIterator.h>
#include <memory>
#include <filesystem>
#include <optional>
#include <cassert>
namespace
{
const UInt64 FORCE_OPTIMIZE_SKIP_UNUSED_SHARDS_HAS_SHARDING_KEY = 1;
const UInt64 FORCE_OPTIMIZE_SKIP_UNUSED_SHARDS_ALWAYS           = 2;
const UInt64 DISTRIBUTED_GROUP_BY_NO_MERGE_AFTER_AGGREGATION = 2;
const UInt64 PARALLEL_DISTRIBUTED_INSERT_SELECT_ALL = 2;
}
namespace ProfileEvents
{