[bartonfink]

Human readability is a concern of a client and is independent of the storage mechanism. Every modern database stores integers in binary format, for instance, but clients display them as a decimal string of characters as opposed to a binary or hexadecimal representation. Timestamps are similarly stored in binary fashion, but often formatted for human readability in the client.

[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

[dozenal]

UUID is not a universally available primitive type like integer or date.

[lectrick]

Someone hasn't used Postgres. http://www.postgresql.org/docs/9.1/static/datatype-uuid.html

And anyway, all a UUID is, ultimately, is a big number. It's a simple transcoding to get it into base-10 integer format and back.