Re: [HACKERS] [POC] Faster processing at Gather node - Mailing list pgsql-hackers

From Andres Freund
Subject Re: [HACKERS] [POC] Faster processing at Gather node
Date
Msg-id 20171115185403.xf476nhzpkgoddor@alap3.anarazel.de
Whole thread Raw
In response to Re: [HACKERS] [POC] Faster processing at Gather node  (Robert Haas <robertmhaas@gmail.com>)
Responses Re: [HACKERS] [POC] Faster processing at Gather node  (Rafia Sabih <rafia.sabih@enterprisedb.com>)
List pgsql-hackers
Hi,

On 2017-11-15 13:48:18 -0500, Robert Haas wrote:
> I think that we need a little bit deeper analysis here to draw any
> firm conclusions.

Indeed.


> I suspect that one factor is that many of the queries actually send
> very few rows through the Gather.

Yep. I kinda wonder if the same result would present if the benchmarks
were run with parallel_leader_participation. The theory being what were
seing is just that the leader doesn't accept any tuples, and the large
queue size just helps because workers can run for longer.


Greetings,

Andres Freund


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