Re: Parallel Seq Scan - Mailing list pgsql-hackers

From Robert Haas
Subject Re: Parallel Seq Scan
Date
Msg-id CA+Tgmoa_oVw5FUJoyE_7C5UudKiSL92ZkXpjVzU37wqLANxzKA@mail.gmail.com
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In response to Re: Parallel Seq Scan  (Stephen Frost <sfrost@snowman.net>)
Responses Re: Parallel Seq Scan
List pgsql-hackers
On Thu, Jan 8, 2015 at 2:46 PM, Stephen Frost <sfrost@snowman.net> wrote:
> Yeah, if we come up with a plan for X workers and end up not being able
> to spawn that many then I could see that being worth a warning or notice
> or something.  Not sure what EXPLAIN has to do anything with it..

That seems mighty odd to me.  If there are 8 background worker
processes available, and you allow each session to use at most 4, then
when there are >2 sessions trying to do parallelism at the same time,
they might not all get their workers.  Emitting a notice for that
seems like it would be awfully chatty.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company



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