Re: [POC] Faster processing at Gather node

On Thu, Oct 19, 2017 at 1:16 AM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> On Tue, Oct 17, 2017 at 5:39 PM, Andres Freund <andres(at)anarazel(dot)de> wrote:
>
>> b) Use shm_mq_sendv in tqueue.c by batching up insertions into the
>> queue whenever it's not empty when a tuple is ready.
>
> Batching them with what? I hate to postpone sending tuples we've got;
> that sounds nice in the case where we're sending tons of tuples at
> high speed, but there might be other cases where it makes the leader
> wait.
>

I think Rafia's latest patch on the thread [1] has done something
similar where the tuples are sent till there is a space in shared
memory queue and then turn to batching the tuples using local queues.

[1] - https://www.postgresql.org/message-id/CAOGQiiNiMhq5Pg3LiYxjfi2B9eAQ_q5YjS%3DfHiBJmbSOF74aBQ%40mail.gmail.com

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