>>10
I've never seen a system using SQL - other than those where SQL is only used as persistent layer - being well designed or easy to maintain. Shit eventually goes all over the place, from UI to business logic, it all gets crapped into a stored procedure, schema, functions and triggers sooner or later, no structure or sense to it at all. DB guys fucking suck at software. The most common issue is performance though, which is usually solved by completely avoiding SQL, by a cache or by some other means, like a simple solution like a text file.