Re: [HACKERS] Parallel tuplesort (for parallel B-Tree index creation)

On Sat, Jan 20, 2018 at 8:33 AM, Peter Geoghegan <pg(at)bowt(dot)ie> wrote:
> On Fri, Jan 19, 2018 at 6:52 PM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>
>> BTW, is there any other way for "parallel create index" to force that
>> the work is done by workers? I am insisting on having something which
>> can test the code path in workers because we have found quite a few
>> bugs using that idea.
>
> I agree that this is essential (more so than supporting
> parallel_leader_participation). You can use the parallel_workers table
> storage parameter for this. When the storage param has been set, we
> don't care about the amount of memory available to each worker. You
> can stress-test the implementation as needed. (The storage param does
> care about max_parallel_maintenance_workers, but you can set that as
> high as you like.)
>

Right, but I think using parallel_leader_participation, you can do it
reliably and probably write some regression tests which can complete
in a predictable time.

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