This is a just for fun project that should never be used in any production enviroment.
The idea was to use the file and folder names to store simple data - and then the content of a file would be the file itself if used as a file storage.
Because filenames take 0 bytes of disc space, I wondered how far I could stretch it and how fast I could make it.
The test in index.php benchmarks fnDB against redis and mysql.
The best, if any, usecase for a thing like this is to have a way of easily storing and fetching files from disc with some aditional information stored in the filename and folder structure without the need for a real database.