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

On Thu, Jan 18, 2018 at 8:53 PM, Robert Haas <robertmhaas@gmail.com> wrote:
> On Thu, Dec 21, 2017 at 9:13 AM, Amit Kapila <amit.kapila16@gmail.com> wrote:
>> I am not against using the way specific to parallel context layer as
>> described by you above.   However, I was trying to see if there is
>> some general purpose solution as the low-impact way is not very
>> straightforward.  I think you can go ahead with the way you have
>> described to fix the hole I was pointing to and I can review it or I
>> can also give it a try if you want to.
>
> See attached.
>

The patch doesn't apply cleanly on the head, but after rebasing it, I
have reviewed and tested it and it seems to be working fine.  Apart
from this specific issue, I think we should consider making
nworkers_launched reliable (at the very least for cases where it
matters).  You seem to be of opinion that can be a source of subtle
bugs which I don't deny but now I think we are starting to see some
use cases of such a mechanism as indicated by Peter G. in parallel
create index thread.  Even, if we find some way for parallel create
index to not rely on that assumption, I won't be surprised if some
future parallelism work would have such a requirement.

-- 
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com