Uniform boolean definitions in DB schemas are good!

I worked briefly in process control when I was younger, and saw Things.™ One of those Things™ was a wall of LEDs to indicate statuses of various valves and sensors across the entire plant. It was old school, but it worked. It also made you feel like you were on a 1960s-era sci-fi set. What does this have to do with databases? That’s an extremely excellent, and dare I say handsome, question. While we’re on the topic of things I used to do, I used to work against a large database that had a schema with a specific quirk that used to drive me up the wall. Take this contrived example of a table for an account: username | active | paid ---------------+--------+------ nagato_yuki | true | true takarada_rikka | true | false And another for some basic infrastructure: hostname | running | error ------------------+---------+------- retro.rubenerd.au | true | false www.sasara.moe | true | true Do you spot the subtle difference between the two? Why is the first table well designed, and the second…