DB names are purely internal to LMDB, so they bear no relation to OS
filenames and none of this discussion matters to them.
If we let the users treat db names as an MDB_val (essentially, an
arbitrary byte array), then all bets are off: we can't even make the
assumption that a db name is meaningful text in any encoding. We can
make it possible to type such a thing in the console if we represent
it as a string of hexadecimal numbers. For example, mdb_dump could do
something like to_hex_string in this code snippet:
http://pastebin.com/jqnGSS6C (note: you need -std=c11 to compile the
snippet).