Horton

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

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: Michael Paquier <michael.paquier@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2018-01-23T16:15:29Z
Lists: pgsql-hackers 
On Mon, Jan 22, 2018 at 10:56 PM, Amit Kapila <amit.kapila16@gmail.com> wrote:
> It does turn such cases into error but only at the end when someone
> calls WaitForParallelWorkersToFinish.  If one tries to rely on it at
> any other time, it won't work as I think is the case for Parallel
> Create Index where Peter G. is trying to use it differently.  I am not
> 100% sure whether Parallel Create index has this symptom as I have not
> tried it with that patch, but I and Peter are trying to figure that
> out.

OK.  I've committed this patch and back-patched it to 9.6.
Back-patching to 9.5 didn't looks simple because nworkers_launched
doesn't exist on that branch, and it doesn't matter very much anyway
since the infrastructure has no in-core users in 9.5.

I'll respond to the other thread about the issues specific to parallel
CREATE INDEX.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

Commits

  1. Report an ERROR if a parallel worker fails to start properly.

  2. Report failure to start a background worker.