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.

There was a protest in every single state capitol on February 3rd and many more cities like San Francisco as well. There will be another 50+ protests on Monday.

I honestly have no clue