[SigmundA]

If it is not recognizably different than it is the same in that context correct?

Two measurements of 25C are not recognizably different therefore they are equal, correct, regardless if the actual temperatures are not the same?

Two measurements of unknown are not recognizably different therefore they are equal in the context of the database.

Having null!=null has never been intuitive to me especially since every other programming language treats them equal. I am not hoping this gets changed, I know SQL is to far along for that, I can still complain about it and agree its wierd.

>And writing things like "value=param or (param is null and value is null)" is usually the sign of a poor understanding of the NULL logic.

It's needed with parametrized sql when your db doesn't support "is not distinct from" which is itself a silly way to just write '=' or '==' like a normal programming language. The distinct predict exist for this very reason to have yet another way to express equality that includes nulls: https://modern-sql.com/caniuse/T151