[lmm]

If you're using an SQL database you're presumably doing so so that humans can run ad-hoc reports (otherwise there are better datastores). So the UX they get for that is important. And in mysql (yes, not the best choice these days, but a reasonable one when the decision was made), if you store UUIDs as binary (there's no native UUID type) then you do not provide a good UX.

[lectrick]

MySQL itself should not be the main interface; there should be some kind of model layer on top of that which does the translation of things like that, such as (for example) ActiveRecord if you were on a Rails stack. That gets you the best of both worlds.

OR you could store the uuid twice, once "natively" and once as a computed column. Searches on the native field would be faster vs. an index on a string column.

> you're presumably doing so so that humans can run ad-hoc reports (otherwise there are better datastores)

oh dear, someone has drank the NoSQL punch... Storing data relationally is NOT something only suitable for ad-hoc queries by end-users! :O