I’m a tech interested guy. I’ve touched SQL once or twice, but wasn’t able to really make sense of it. That combined with not having a practical use leaves SQL as largely a black box in my mind (though I am somewhat familiar with technical concepts in databasing).
With that, I keep seeing [pic related] as proof that Elon Musk doesn’t understand SQL.
Can someone give me a technical explanation for how one would come to that conclusion? I’d love if you could pass technical documentation for that.
There can be duplicate SSNs due to name changes of an individual, that’s the easiest answer. In general, it’s common to just add a new record in cases where a person’s information changes so you can retain the old record(s) and thus have a history for a person (look up Slowly Changing Dimensions (SCD)). That’s how the SSA is able to figure out if a person changed their gender, they just look up that information using the same SSN and see if the gender in the new application is different from the old data.
Another accusation Elon made was that payments are going to people missing SSNs. The best explanation I have for that is that various state departments have their own on-premise databases and their own structure and design that do not necessarily mirror the federal master database. There are likely some databases where the SSN field is setup to accept strings only, since in real life, your SSN on your card actually has dashes, those dashes make the number into a string. If the SSN is stored as a string in a state database, then when it’s brought over to the federal database (assuming the federal db is using a number field instead of text), there can be some data loss, resulting in a NULL.