Ordinary database engine is deprecated but there is no simple mean to change database engine to Atomic for existing databases.

Possible options:
- ALTER DATABASE MODIFY ENGINE query.
- Flag that triggers migration at ClickHouse startup.

The latter should be easier to implement. 

storage_metadata.setConstraints(constraints_);
    storage_metadata.setComment(comment);
    setInMemoryMetadata(storage_metadata);
    if (relative_path_.empty())
        throw Exception("Storage " + getName() + " requires data path", ErrorCodes::INCORRECT_FILE_NAME);
    
    if (file_checker.empty())
    {
        file_checker.setEmpty(data_file_path);
        file_checker.setEmpty(index_file_path);
    }
    if (!attach)
    {
        
        disk->createDirectories(table_path);
    }
    else
    {
        try
        {
            file_checker.repair();
        }
        catch (...)
        {
            tryLogCurrentException(__PRETTY_FUNCTION__);
        }
    }
    total_bytes = file_checker.getTotalSize();
}
StorageStripeLog::~StorageStripeLog() = default;