You’re completely missing the point. Many multi master databases exist. Network partitions happen. Bugs in multi master databases during network partitions have happened and can happen. This is like distributed systems 101.
So given those facts, your design of using UUIDs is absolutely not full proof if the database where you stored your UUID is not in a consistent state.
“ Data consistency means that all nodes or replicas agree on the same value of a data (or eventually agree in the context of eventual consistency). In reality, there are several cases (5%) where data consistency is violated and users get stale data or the system’s behavior becomes erratic. The root causes mainly come from logic bugs in operational protocols (43%), data races (29%) and failure handling problems (10%).1 Be- low we expand these problems.”
So given those facts, your design of using UUIDs is absolutely not full proof if the database where you stored your UUID is not in a consistent state.
Here’s some more useful info for your perusal (https://ucare.cs.uchicago.edu/pdf/socc14-cbs.pdf)
“ Data consistency means that all nodes or replicas agree on the same value of a data (or eventually agree in the context of eventual consistency). In reality, there are several cases (5%) where data consistency is violated and users get stale data or the system’s behavior becomes erratic. The root causes mainly come from logic bugs in operational protocols (43%), data races (29%) and failure handling problems (10%).1 Be- low we expand these problems.”