Derek Hans <derek.hans@gmail.com> writes:
> Unfortunately only "alter function" supports "leakproof" - "alter operator"
> does not. Is there a function-equivalent for marking operators as
> leakproof?
Leakproofness is a property of the underlying function, not the operator,
so that's where you change it.
> Is there any documentation for which operators/functions are
> leakproof?
select oid::regprocedure from pg_proc where proleakproof;
regards, tom lane