What's your opinion on using UUIDs as database row identifiers, particularly in web apps?

Question

I\'ve always preferred to use long integers as primary keys in databases, for simplicity and (assumed) speed. But when using a REST or Rails-like URL scheme for object insta

Answer 1

Why couple your primary key with your URI?

Why not have your URI key be human readable (or unguessable, depending on your needs), and your primary index integer based, that way you get the best of both worlds. A lot of blog software does that, where the exposed id of the entry is identified by a 'slug', and the numeric id is hidden away inside of the system.

The added benefit here is that you now have a really nice URL structure, which is good for SEO. Obviously for a transaction this is not a good thing, but for something like stackoverflow, it is important (see URL up top...). Getting uniqueness isn't that difficult. If you are really concerned, store a hash of the slug inside a table somewhere, and do a lookup before insertion.

edit: Stackoverflow doesn't quite use the system I describe, see Guy's comment below.