Hello, I'm a bit late to the party, but I'll put that for posterity:

There's a way to rename your weird two letter named folders and still have your table working, but it violates the good practices guidelines suggested by Data Bricks, and I don't think you should really use it, but hey, it works for me.

- After modifying your table, you have to check the _data_log json files for lines that add directories to the table. Look for the lines that start with {"add".

- In it you should check for the "path" parameter which should contain one of your weird two letter named folder followed by the actual file that was added (ex: {"add":{"path":"Mz/part-00000-493eaa18-4b8c-78ad-907e-g213fc315643.c000.snappy.parquet")

- Rename the  weird folder after the partition you wanted (ex: "path":"date=20240207/part-00000-493eaa18-4b8c-78ad-907e-g213fc315643.c000.snappy.parquet")

-Then go to your weird folder and rename it with the same name so your delta log can find it.

If you have multiple weird folders for the same partition, create your new folder first, then move the files from the weird folders to the new one (and you can delete the empty weird folders afterward).

You can automate that with a python notebook so you don't have to do all of this by hand everytime you change your table, and add the notebook at the end of your Work Flows or other notebooks to be sure to never skip any waird directories.

Now your table should be good and you can do queries. I mean it was already good, but now you can easily find your datas with your file explorer.

Once again, I'm pretty sure that's not a safe method to do that (cuz don't mess with the logs), and you probably should just be content with weirdly named folders, but if your data treatment need the right folder names, then this works just fine.