Storing UUID's in their binary format quickly becomes a PITA for debugging or doing manual queries. Some DB's have functions that can convert to human-readable

Storing UUID's in their binary format quickly becomes a PITA for debugging or doing manual queries. Some DB's have functions that can convert to human-readable strings which make this less painful, but it's never going to be as simple as using integer id's. As with all things, there are tradeoffs that must be considered before building the system.