

Worth noting is that “good” database design evolved over time (https://en.wikipedia.org/wiki/Database_normalization). If anything was setup pre-1970s, they wouldn’t have even had the conception of the normal forms used to cut down on data duplication. And even after they were defined, it would have been quite a while before the concepts trickled down from acedmemia to the engineers actually setting up the databases in production.
On top of that, name to SSN is a many-to-many relationship - a single person can legally change their name, and may have to apply for a new SSN (e.g. in the case of identity theft). So even in a well normalized database, when you query the data in a “useful” form (e.g. results include name and SSN), it’s probably going to appear as if there are multiple people using the same SSN, as well as multiple SSNs assigned to the same person.
Go see a show at The Comedy Cellar. Book it in advance if you can. If it’s “sold out,” you can still show up and wait before showtime - I think they only sell about half the seats online, so if you show up 30-60 minutes before the show, you can probably get in.