I think what he means is that the unique identifier for a database record is a composite of two fields: SSN + birth date. That doesn’t mean that SSN to birth date is a one-to-many relation.
But they are implying SSN to SSN+Birthdate is a one-to-many relationship. Since SSN to SSN should be one-to-one, you can conclude the SSN to Birthdate is one-to-many, right?
A weak example would be my grandma. She was born before social security and was told as a kid she was born in 1938. Because I guess in the olden days, you just didn’t need to pass your birth certificate around for anything, it wasn’t until she went to get married at ~age 25 that her birth certificate actually said she was born in 1940 (I forget the actual years, but I remember it was a two year and two day gap between dates).
Its a weak example that should apply to only a microscopic portion of the population, but I could see her having some weird records in the databases as a result.
BombOmOm@lemmy.world 9 months ago
Why would one person, one SSN ever have two different birth dates? That sounds like an issue all into itself.
geoff@lemm.ee 9 months ago
I think what he means is that the unique identifier for a database record is a composite of two fields: SSN + birth date. That doesn’t mean that SSN to birth date is a one-to-many relation.
DahGangalang@infosec.pub 9 months ago
But they are implying SSN to SSN+Birthdate is a one-to-many relationship. Since SSN to SSN should be one-to-one, you can conclude the SSN to Birthdate is one-to-many, right?
natecox@programming.dev 9 months ago
DahGangalang@infosec.pub 9 months ago
A weak example would be my grandma. She was born before social security and was told as a kid she was born in 1938. Because I guess in the olden days, you just didn’t need to pass your birth certificate around for anything, it wasn’t until she went to get married at ~age 25 that her birth certificate actually said she was born in 1940 (I forget the actual years, but I remember it was a two year and two day gap between dates).
Its a weak example that should apply to only a microscopic portion of the population, but I could see her having some weird records in the databases as a result.