I read a good post over at debuggable just now, about UUIDs.  One of the things about the article that struck me that I didn’t know, is that if you have a char(36) field, cake will just start to use them, auto-magically.

This means that in real world application effort wise, auto incrementing ints, or UUIDs are both super easy to use in cake.  Nearly no difference other than your table creation.

This got me thinking about which one is better.  Well, the url’s look better as ints, say ‘/applications/view/147′ versus ‘/applications/view/48c907b0-f088-44ae-8be5-4e811030b5da’.  One is way shorter as well.

Some people quote SEO has being a disadvantage to UUIDs.  I don’t know about that.  It would seem to be that they could be about equal, if both given the same treatment, like putting title in the address.  I would assume that they are equal, but I am not quite sure about this.

The main advantage of UUIDs is uniqueness.  I can see why true uniqueness would be cool.  No centralized system, but yet you have a unique Id.   Merging tables because easy, makes url hacks harder.

So for me the equation is uniqueness versus easier urls.