Comment by gregwebs

Everything breaks at scale. In my experience most tables don't end up with more than a few million rows and will work fine with this. If you did want to transition a large table to be UUID only, the nice thing about this approach is that you could do it with no down time. If you are using a DB that only scales writes vertically though (most DBs, including distributed DBs) then how are you actually going to scale the DB layer horizontally? Pretty much just CRDB (PG) or TiDB (MySQL) are the options there- look at their docs for how to setup your ids.