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.
```
}
    }
    return std::make_unique<QueryPipeline>(QueryPipeline::unitePipelines(std::move(pipelines)));
}
void StorageDistributed::checkAlterIsPossible(const AlterCommands & commands, ContextPtr local_context) const
{
    auto name_deps = getDependentViewsByColumn(local_context);
    for (const auto & command : commands)
    {
        if (command.type != AlterCommand::Type::ADD_COLUMN
            && command.type != AlterCommand::Type::MODIFY_COLUMN
            && command.type != AlterCommand::Type::DROP_COLUMN
            && command.type != AlterCommand::Type::COMMENT_COLUMN
            && command.type != AlterCommand::Type::RENAME_COLUMN)
            throw Exception("Alter of type '" + alterTypeToString(command.type) + "' is not supported by storage " + getName(),
                ErrorCodes::NOT_IMPLEMENTED);
        if (command.type == AlterCommand::DROP_COLUMN)
        {
            const auto & deps_mv = name_deps[command.column_name];
            if (!deps_mv.empty())
            {
                throw Exception(
                    "Trying to ALTER DROP column " + backQuoteIfNeed(command.column_name) + " which is referenced by materialized view "
                        + toString(deps_mv),
                    ErrorCodes::ALTER_OF_COLUMN_IS_FORBIDDEN);
            }
        }
    }
}
void StorageDistributed::alter(const AlterCommands & params, ContextPtr local_context, TableLockHolder &)