on MySQL or any database that doesn't have it as a datatype, its 36 char on latin charset. If you leave everything as UTF-8, then its x3 that amount.
Try it for yourself.
Try it for yourself.
As a side comment about MySQL, there are various techniques to store UUID more compactly as 16 bytes inside of a "binary(16)" type like this:
https://stackoverflow.com/a/28252188
... or similar technique shown at the bottom of the Percona blog:
https://www.percona.com/blog/2014/12/19/store-uuid-optimized...