He’s doing a “census audit” and trying to consolidate a lot of different datasets from different sources containing the same individuals. None of the sources contain any sort of unique ID column in common so he’s using the SSN I guess to join tables? I don’t fully understand what he’s doing. I don’t think he actually has a functioning relational database setup. The few glimpses I’ve seen of his Access database looks chaotic.

Separately I made a simple database with the same persons for the purposes of generating monthly invoices, and I gave them auto-increment IDs; my database is supposed to link to his because he wants to monitor record changes and incorporate them into his ongoing census thing. But he’s not liking my primary key and keeps wanting me to switch to SSNs so it’s easier for him to do whatever he’s doing.