Re: Parallel worker error

On Sat, Sep 2, 2017 at 12:21 PM, Noah Misch <noah(at)leadboat(dot)com> wrote:
> On Thu, Aug 31, 2017 at 03:11:10PM -0400, Robert Haas wrote:
>> On Wed, Aug 30, 2017 at 11:19 AM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>> > But since that's an established design fl^H^Hprinciple, maybe that
>> > means we should go with the approach of teaching SerializeGUCState()
>> > to ignore role altogether and instead have ParallelWorkerMain call
>> > SetCurrentRoleId using information passed via the FixedParallelState
>> > (not sure of the precise details here).
>>
>> Could I get some opinions on the virtues of this approach, vs. any of
>> the other suggestions at or near
>> http://postgr.es/m/CA+TgmoaSP90E33-MU2YpGs73TtJ37m5Hv-xqHjc7TPqX9wX8ew@mail.gmail.com
>> ?
>
> It seems good to me, better than the other options in that mail.
>

It seems like the consensus is to move forward with this approach. I
have written a patch implementing the above idea. Note, that to use
SetCurrentRoleId, we need the value of guc "is_superuser" for the
current user and we don't pass this value to parallel workers as this
is PGC_INTERNAL guc variable. So, I have passed this value via
FixedParallelState.

After this patch, I think the check of InitializingParallelWorker in
check_role function is redundant. I have prepared a separate patch
for it, but may be it can be handled with the main patch to fix the
issue.

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