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.

It's more than just SQL. Social Security Numbers can be re-used over time. It is not a unique identifier by itself.

To me I'm not really sure what his reply even means. I think it's some attempt at a joke (because of course the government uses SQL), but I figure the joke can be broken down into two potential jokes that fail for different, embarrassing reasons:

Interpretation 1: The government is so advanced it doesn't use SQL - This interpretation is unlikely given that Elon is trying to portray the government as in need of reform. But it would make more sense if coming from a NoSQL type who thinks SQL needs to be removed from everywhere. NoSQL Guy is someone many software devs are familiar with who takes the sometimes-good idea of avoiding SQL and takes it way too far. Elon being NoSQL Guy would be dumb, but not as dumb as the more likely interpretation #2.

Interpretation 2: The government is so backward it doesn't use SQL - I think this is the more likely interpretation as it would be consistent with Elon's ideology, but it really falls flat because SQL is far from being cutting-edge. There has kind of been a trend of moving away from SQL (with considerable controversy) over the last 10 years or so and it's really surprising that Elon seems completely unaware of that.

Having never seen the database schema myself, my read is that the SSN is used as a primary key in one table, and many other tables likely use that as a foreign key. He probably doesn't understand that foreign keys are used as links and should not be de-duplicated, as that breaks the key relationship in a relational database. As others have mentioned, even in the main table there are probably reused or updated SSNs that would then be multiple rows that have timestamps and/or Boolean flags for current/expired.

The statement "this [guy] thinks the government uses SQL" demonstrates a complete and total lack of knowledge as to what SQL even is. Every government on the planet makes extensive and well documented use of it.

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.

If he knew the domain, he would know this isn't an issue. If he knew the technology he would be able to see the constraint and following investigation, reach the conclusion that it's not an issue.

The man continues to be a malignant moron

It's an insanely idiotic thing to say. Federal government IT is myriad, and done at a per agency level. Any relational database system, which the federal government uses plenty of, uses SQL in one way or another. Elon doesn't know what he is talking about at all, and is being an ultimate idiot about this. Even in the context of mainframe projects thatif we are giving elong the benefit of doubt about referring to, most COBOL shoprbibknow have adapted to addressing internal data records using an SQL interface, although obviously in that legacy world it is insanely fractured and arcane.

The US government pays lots of money to Oracle to use their database. And it's not for BerkleyDB either. (Poor sleepy cat). Oracle provides them support for their relational databases... and those databases use... SQL.

Now if Musk tries to end the Oracle contracts, then Oracle's lawyers will go after his lawyers and I'm a gonna get me some popcorn. (But we all know that won't happen in any timeline... Elon gotta keep Larry happy.)

The ignorance of Elon is truly concerning, but somehow the worst part to me is Elon calling someone a retard for pointing that out.

Its because the comments he made are inconsistent with common conventions in data engineering.

1. It is very common not to deduplicate data and instead just append rows, The current value is the most recent and all the old ones are simply historical. That way you don't risk losing data and you have an entire history.
   • whilst you could do some trickery to deduplicate the data it does create more complexity. There's an old saying with ZFS: "Friends don't let friends dedupe" And it's much the same here.
   • compression is usually good enough. It will catch duplicated data and deal with it in a fairly efficient way, not as efficient as deduplication but it's probably fine and it's definitely a lot simpler
2. Claiming the government does not use SQL
   • It's possible they have rolled their own solution or they are using MongoDB Or something but this would be unlikely and wouldn't really refute the initial claim
   • I believe many other commenters noted that it probably is MySQL anyway.

Basically what he said is ~~incoherent~~ inconsistent with typical practices among data engineers ~~to anybody who has worked with larger data.~~

In terms of using SQL, it's basically just a more reliable and better Excel that doesn't come with a default GUI.

If you need to store data, It's almost always best throw it into a SQLite database Because it keeps it structured. It's standardised and it can be used from any programming language.

However, many people use excel because they don't have experience with programming languages.

Get chatGpt to help you write a PyQT GUI for a SQLite database and I think you would develop a high level understanding for how the pieces fit together

Edit: @zalgotext made a good point.

Clearly the solution is to just use a big Excel spreadsheet.

Musk's statement about the government not using SQL is false. I worked for FEMA for fourteen years, a decade of which was as a Reports Analyst. I wrote Oracle SQL+ code to pull data from a database and put it into spreadsheets. I know, I know. You're shocked that Elon Musk is wrong. Please remain calm.

Elon Musk is the walking talking embodiment of the Dunning-Kruger effect.

"The government" is multiple agencies and departments. There is no single computer system, database, mainframe, or file store that the entire US goverment uses. There is no standard programming language used. There is no standard server configuration. Each agency is different. Each software project is different.

When someone says the government doesn't use sql, they don't know what they are talking about. It could be refering to the fact that many government systems are ancient mainframe applications that store everything in vsam. But it is patently false that the government doesn't use sql. I've been on a number of government contracts over the years, spanning multiple agencies. MsSQL was used in all but one.

Furthermore, some people share SSNs, they are not unique. It's a common misconception that they are, but anyone working on a government software learns this pretty quickly. The fact that it seems to be a big shock goes to show that he doesn't know what he is doing and neither do the people reporting to him.

Not only is he failing to understand the technology, he is failing to understand the underlying data he is looking at.

As a data engineer for the past 20+ years: There is absolutely no fucking way that the us gov doesnt use sql. This is what shows that he’s stupid not only in sql but in data science in general.

Regarding duplications: its more nuanced than those statements each side put. There can be duplications in certain situations. In some situations there shouldnt be. And I dont really see how duplications in a db is open to fraud.

He is saying the US government doesn't use structured databases.

At least 90% of all databases have a structure.

139 comments and no one addresses his use of a slur.

He's just a permanent petulant child.