Okay but if that happens, musk is right that that's a bit of a denormalization issue that mayne needs resolving.
SSNs should be stored as strings without any hyphen or additional markup, nothing else.
- Storing as a number can cause issues if you ever wanna support trailing zeros
- any "styling" like hyphens should be handled by a consuming front end system, you want only the important data in the DB to maximize query times
It's more likely though it's just a composite key...
Sure but my point is, if it was the scenario you described, then Elon would be talking about the right kind of denormalization problem.
Denormalization due to multiple different tables storing their own copies of the same data, in different formats worse yet, would actually be the kind of problem he's tweeting about.
As opposed to a composite key on one table which means him being an ultracrepidarian, as usual.