"He who loves practice without theory is like the sailor who boards ship without a rudder and compass and never knows where he may cast." -- Leonardo da Vinci

My first paying IT job was in 1965. That's over 50 years in this trade; my consolation is that I got old by not dying. 🙂 Please don't tell me that I'm all theory. I was a code monkey for over 25 years. However, if you want to yell at me for being all "ANSI/ISO standards", "mathematical correctness", "best practices in the industry", "decades of research behind me" and pedantic as all merry hell, I will agree.

Basically, at some point, people were paying me to fix the messes that have been made by People like you, who think that it's okay to compromise on things. You have given me most of my later SQL consulting work. I fix bad designs and I'm expensive. But it's cheaper than living with a bad design of somebody wanted to save the cost of some storage, or kludge a program to cover a bad design..

I also agree that display has nothing to do with storage. Those things we show decimals are stored as binary. Of course we don't know if it's high-end or low-end storage or maybe on a it old Russian three valued machine. However, I like Brent's law that data should be stored the way it's used and use it the way it's stored. This means that a human being can read it, that pattern matching is a lot easier, check digits are easier to compute, etc. It's important to pick the level of abstraction (physical hardware, programming language, particular product, etc.) for your design. In the database, deciding to optimize at the current hardware/software level is always wrong.

I wrote one of the first articles on the Y2K problems in Information Systems News when I had a regular column. It was all too familiar with what would happen we got to the cusp of 1999 – 2000 and had to decide which decade ambiguous dates would fall. This decision was totally dependent on your data. You would be surprised by the percentage of errors you got trying to add the century. We have a lot of people that live over 90. Now tell me if a birthdate year is 19xx or 20xx in the hospital that treats both geriatrics and pediatrics. Whoever thought this was "a correct decision at the time" bought me a car at the time I got through cleaning of their data. Our slogan was "another day, another K, and we mean take-home pay" for jobs like this.