Re: [HACKERS] intermittent failures in Cygwin from select_parallel tests - Mailing list pgsql-hackers

From Tom Lane
Subject Re: [HACKERS] intermittent failures in Cygwin from select_parallel tests
Date
Msg-id 10063.1497561363@sss.pgh.pa.us
Whole thread Raw
In response to Re: [HACKERS] intermittent failures in Cygwin from select_parallel tests  (Robert Haas <robertmhaas@gmail.com>)
Responses Re: [HACKERS] intermittent failures in Cygwin from select_parallel tests  (Robert Haas <robertmhaas@gmail.com>)
List pgsql-hackers
Robert Haas <robertmhaas@gmail.com> writes:
> On Thu, Jun 15, 2017 at 5:06 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> ... nodeGather cannot deem the query done until it's seen EOF on
>> each tuple queue, which it cannot see until each worker has attached
>> to and then detached from the associated shm_mq.

> Oh.  That's sad.  It definitely has to wait for any tuple queues that
> have been attached to be detached, but it would be better if it didn't
> have to wait for processes that haven't even attached yet.

Hm.  We assume they attach before they start taking any of the query
work?  Seems reasonable, and this would give us some chance of recovering
from worker fork failure.
        regards, tom lane



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