Re: [HACKERS] parallel.c oblivion of worker-startup failures

Robert Haas <robertmhaas@gmail.com> writes:
> I'm not in love with that part of the fix; the other parts of that if
> statement are just testing variables, and a function call that takes
> and releases an LWLock is a lot more expensive.  Furthermore, that
> test will often be hit in practice, because we'll often arrive at this
> function before workers have actually finished.  On top of that, we'll
> typically arrive here having already communicated with the worker in
> some way, such as by receiving tuples, which means that in most cases
> we already know that the worker was alive at least at some point, and
> therefore the extra test isn't necessary.  We only need that test, if
> I understand correctly, to cover the failure-to-launch case, which is
> presumably very rare.

Maybe track "worker is known to have launched" in the leader's state
someplace?

            regards, tom lane