| From: | Amit Langote <Langote_Amit_f8(at)lab(dot)ntt(dot)co(dot)jp> |
|---|---|
| To: | Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> |
| Cc: | Haribabu Kommi <kommi(dot)haribabu(at)gmail(dot)com>, Robert Haas <robertmhaas(at)gmail(dot)com>, Andres Freund <andres(at)2ndquadrant(dot)com>, Kouhei Kaigai <kaigai(at)ak(dot)jp(dot)nec(dot)com>, Amit Langote <amitlangote09(at)gmail(dot)com>, Fabrízio Mello <fabriziomello(at)gmail(dot)com>, Thom Brown <thom(at)linux(dot)com>, Stephen Frost <sfrost(at)snowman(dot)net>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: Parallel Seq Scan |
| Date: | 2015-03-13 04:52:36 |
| Message-ID: | 55026D14.2090604@lab.ntt.co.jp |
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| Lists: | pgsql-hackers |
On 13-03-2015 PM 01:37, Amit Langote wrote:
> By the way, is it right that TupleQueueFunnel.queue has one shm_mq_handle per
> initialized parallel worker? If so, how does TupleQueueFunnel.maxqueues relate
> to ParallelContext.nworkers (of the corresponding parallel context)?
>
> Why I asked this is because in CreateTupleQueueFunnel():
>
> funnel->maxqueues = 8;
> funnel->queue = palloc(funnel->maxqueues * sizeof(shm_mq_handle *));
>
> So, is the hardcoded "8" intentional or an oversight?
>
Oh, I see that in RegisterTupleQueueOnFunnel(), the TupleQueueFunnel.queue is
expanded (repalloc'd) if needed as per corresponding pcxt->nworkers.
Thanks,
Amit
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