The point of UUIDs is that they're inherently unique. You can generate them in the database or in your application, or anywhere. You can move records between da

The point of UUIDs is that they're inherently unique. You can generate them in the database or in your application, or anywhere. You can move records between databases without worrying about a collision. Its this reason that theyre so useful and so many people use them that others like to write articles like this. You do not need to search. I have generated hundreds of millions and have never hit a duplicate. Its technically possible, but its so vanishingly rare it will be something to brag about, not worry about. If you're really worried about it, and building something that cannot tolerate an error, put a try/catch around it and detect a PK failure and try again. But it will be a waste of time.