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.

  • snooggums@lemmy.worldEnglish
    291·
    8 days ago

    The initial statement I believe is down to a combination of the above and also the lack of domain knowledge around social security. The primary key on the social security table would be a composite key of both the SSN and a date of birth—duplicates are expected of just parts of the key.

    Since SSNs are never reused, what would be the purpose of using the SSN and birth date together as part of the primary key? I guess it is the one thing that isn’t supposed to ever change (barring a clerical error) so I could see that as a good second piece of information, just not sure what it would be adding.

    Note: if duplicate SSNs are accidentally issued my understanding is that they issue a new one to one of the people and I don’t know how to find the start of the thread on twitter since I only use it when I accidentally click on a link to it.

    https://www.ssa.gov/history/hfaq.html

    Q20: Are Social Security numbers reused after a person dies?

    A: No. We do not reassign a Social Security number (SSN) after the number holder’s death. Even though we have issued over 453 million SSNs so far, and we assign about 5 and one-half million new numbers a year, the current numbering system will provide us with enough new numbers for several generations into the future with no changes in the numbering system.

    • DahGangalang@infosec.pubOP
      2·
      8 days ago

      Beat me to asking this follow up, though you linking additional resources is probably more effort that I would have done. Thanks for that!

    • Lightor@lemmy.world
      1·
      7 days ago

      My guess would be around your note. If someone mistakenly has two SSNs (due to fraud, error, or name changes), combining DOB helps detect inconsistencies.

      Some other possibilities, and I’m just throwing out ideas at this point:

      • Adding DOB could help with manual lookups and verification.
      • Using SSN + DOB ensures a standard key format across agencies, making it easier to link records.
      • Prevents accidental duplication if an SSN is mistyped.
      • Maybe the databases were optimized for fixed-length fields, and combining SSN + DOB fit within memory constraints.
      • It was easier to locate records with a “human-readable” key. Where as something like a UUID is harder for humans to read or sift through.