It's astonishing that searching for a file name by substring across a file system is still not instantaneous on most systems. On my laptop (a 2GHz Quad-Core Intel Core i5), `find / -iname 'quux' takes 2 minutes to find matches across an APFS partition with 2m files. Grepping for a substring in a file with 2m lines takes a few milliseconds. Why don't modern file systems implement something like the `locate` database, except one that is always up-to-date, so that scanning for a file does not require expensive traversal?