In a database course I took, the teacher told a story about a company that would take three days to insert a single order. Thing was, they were the sort of company that took in one or two orders every year. When it's your whole revenue on the line, you want to make sure everything is correct. The relations in that database were checked to hell and back, and they didn't care if it took a week.

Though that would have been in the 90s, so it'd go a lot faster now.