I'm trying to remember a word, I think it's related to computational or database theory. The closest synonym is atomic but that's not exactly it. Basically it's a kind of computation that should produce the same result even when run multiple times in a row, meaning it doesn't create side effects for itself.

I specifically ran across this word in a Stack Overflow answer about a chmod command (or some other permission related operation).

Hopefully that's enough to go on. Poking around Wikipedia isn't much help.

You might be thinking of "Idempotent".


  Idempotence is the property of certain operations in mathematics and computer science, that they can be applied multiple times without changing the result beyond the initial application. 

