Re: IMMUTABLE and PARALLEL SAFE function markings

>>>>> "Robert" == Robert Haas <robertmhaas(at)gmail(dot)com> writes:

>> I'm a bit more concerned by the fact that inlining the function
>> isn't affecting the parallel safety of the query - the fact that
>> parallel safety is being checked prior to inlining means that if
>> inlining *introduces* a parallel hazard, it will go unnoticed?

Robert> If a function is marked parallel-safe but internally calls
Robert> parallel-restricted or parallel-unsafe functions, it wasn't
Robert> really parallel-safe in the first place. So I think that if
Robert> inlining introduces a parallel hazard, the user has mislabeled
Robert> some functions and any resulting injury is self-inflicted.

But the combination of inlining and polymorphism, in particular, makes
it impossible for the function author to know this. Take the OP's
example; it is parallel safe if and only if the selected type's equal
function is parallel safe - how is the author supposed to know? What if
the type is one installed later?

--
Andrew (irc:RhodiumToad)