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.
SSNs being duplicated would be entirely expected depending upon the table’s purpose. There are many forms of normalization in database tables.
I mean just think about this a little bit, if the purpose is transactions or something and each row has a SSN reference in it for some reason, you’d have a duplicate SSN per transaction row.
A tiny bit of learning SQL and you could easily see transactional totals grouped by SSN (using, get this, a group by clause). This shit is all 100% normal depending upon the normalization level of the schema. There are even – almost obviously – tradeoffs between fully normalizing data and being able to access it quickly. If I centralize the identities together and then always only put the reference id in a transactional table, every query that needs that information has to go join to it and the table can quickly become a dependency knot.
There was a “member” table for instance in an IBM WebSphere schema that used to cause all kinds of problems, because every single record was technically a “member” so everything in the whole system had to join to it to do anything useful.