Re: Rename max_parallel_degree? - Mailing list pgsql-hackers

From Julien Rouhaud
Subject Re: Rename max_parallel_degree?
Date
Msg-id 20312f33-c14e-0d3f-a79f-95212f64a38c@dalibo.com
Whole thread Raw
In response to Re: Rename max_parallel_degree?  (Amit Kapila <amit.kapila16@gmail.com>)
Responses Re: Rename max_parallel_degree?  (Amit Kapila <amit.kapila16@gmail.com>)
Re: Rename max_parallel_degree?  (Amit Kapila <amit.kapila16@gmail.com>)
List pgsql-hackers
On 29/06/2016 06:29, Amit Kapila wrote:
> On Wed, Jun 29, 2016 at 2:57 AM, Julien Rouhaud
> <julien.rouhaud@dalibo.com> wrote:
>>
>> Thanks a lot for the help!
>>
>> PFA v6 which should fix all the issues mentioned.
>
> Couple of minor suggestions.
>
> -         <xref linkend="guc-max-worker-processes">.  Note that the requested
> +         <xref linkend="guc-max-worker-processes">, limited by
> +         <xref linked="guc-max-parallel-workers">.  Note that the requested
>
> Typo.
> /linked/linkend
>

Oops, fixed.

> You can always find such mistakes by doing make check in doc/src/sgml/
>

I wasn't aware of that, it's really a nice thing to know, thanks!

> + /*
> + * We need a memory barrier here to make sure the above test doesn't get
> + * reordered
> + */
> + pg_read_barrier();
>
> /memory barrier/read barrier
>

fixed

> + if (max_parallel_workers == 0)
> + {
> + ereport(elevel,
> + (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
> + errmsg("background worker \"%s\": cannot request parallel worker if
> no parallel worker allowed",
>
> " ..no parallel worker is allowed".  'is' seems to be missing.
>

fixed

>
>>  Also, after second
>> thought I didn't add the extra hint about max_worker_processes in the
>> max_parallel_worker paragraph, since this line was a duplicate of the
>> precedent paragraph, it seemed better to leave the text as is.
>>
>
> not a big problem, we can leave it for committer to decide on same.
> However just by reading the description of max_parallel_worker, user
> can set its value more than max_wroker_processes which we don't want.
>

Right.  On the other hand I'm not sure that's really an issue, because
such a case is handled in the code, and setting max_parallel_workers way
above max_worker_processes could be a way to configure it as unlimited.
Or should we allow setting it to -1 for instance to disable the limit?

--
Julien Rouhaud
http://dalibo.com - http://dalibo.org

Attachment

pgsql-hackers by date:

Previous
From: Oleg Bartunov
Date:
Subject: Re: Gin index on array of uuid
Next
From: Amit Kapila
Date:
Subject: Re: Rename max_parallel_degree?