Wolfgang Amadeus Mozart was a great composer, but it is less known that he completely sucked at relational databases.

Mozart was a very active prodigy with many revisions and variations of his works. He kept no catalogue himself, his manuscripts were all over the place, and some were discovered after his death only (when forgeries started appearing too). Many of his works lacked a title or any other way they could be unambiguously identified. Thus, people were confused when referring to Mozart's works, some wondering cluelessly like: 'You know the one that starts like 🎶🎵 [humming]... No, not that one, the one that continues as 🎵🎶 [humming]...' Even counting his works was a challenge. Mozart did not use any unique id; he clearly did not think of people later trying to organize his works into an SQL database. 😄

Then came Mozart-researcher superhero🦸 Ludwig von Köchel, who said: 'Let's number Mozart's works in chronological order!' So hath Köchel spoken, the Köchel catalogue was born, and there was confusion no more. (*)

➡️ Assigning ids is a surprisingly simple and effective solution.

➡️ While you cannot blame Mozart for not using unique ids 300 years before computers, it is just surprising how many times we see in today's world long lists of 'stuff' without any way to navigate, identify items, tell them apart or count them.

➡️ For me as a security guy: it is really tough to secure something you cannot even count... 😫

*: Actually, people kept discovering new works of Mozart, and some were re-dated / re-attributed, so the Köchel catalogue had to be re-numbered a couple of times. Today it sounds like a better idea to say: 'Let's number them in any order and do not change those numbers ever as ids must be immutable'. (see 9th edition of Köchel catalogue)

This post was first published on Linkedin here on 2025-09-28.