Re: Parallel Seq Scan - Mailing list pgsql-hackers

From Stephen Frost
Subject Re: Parallel Seq Scan
Date
Msg-id 20150105152107.GQ3062@tamriel.snowman.net
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In response to Re: Parallel Seq Scan  (Robert Haas <robertmhaas@gmail.com>)
Responses Re: Parallel Seq Scan
List pgsql-hackers
* Robert Haas (robertmhaas@gmail.com) wrote:
> I think it's right to view this in the same way we view work_mem.  We
> plan on the assumption that an amount of memory equal to work_mem will
> be available at execution time, without actually reserving it.

Agreed- this seems like a good approach for how to address this.  We
should still be able to end up with plans which use less than the max
possible parallel workers though, as I pointed out somewhere up-thread.
This is also similar to work_mem- we certainly have plans which don't
expect to use all of work_mem and others that expect to use all of it
(per node, of course).
Thanks,
    Stephen

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