Re: Parallel query and temp_file_limit

On Tue, Jun 21, 2016 at 8:15 AM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> On Mon, Jun 20, 2016 at 11:01 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> Peter Geoghegan <pg(at)heroku(dot)com> writes:
>>> On Wed, May 18, 2016 at 3:40 AM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>>>> What I'm tempted to do is trying to document that, as a point of
>>>> policy, parallel query in 9.6 uses up to (workers + 1) times the
>>>> resources that a single session might use. That includes not only CPU
>>>> but also things like work_mem and temp file space. This obviously
>>>> isn't ideal, but it's what could be done by the ship date.
>>
>>> Where would that be documented, though? Would it need to be noted in
>>> the case of each such GUC?
>>
>> Why can't we just note this in the number-of-workers GUCs? It's not like
>> there even *is* a GUC for many of our per-process resource consumption
>> behaviors.
>
> +1.

Since Peter doesn't seem in a hurry to produce a patch for this issue,
I wrote one. It is attached. I'll commit this in a day or two if
nobody objects.

--
Robert Haas
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